Core

How many atoms of nitrogen are there in 0.50 mol of (NH₄)₂CO₃?

A. 1

B. 2

C. 3.01 × 10²³

D. 6.02 × 10²³

How many atoms of nitrogen are there in 0.50 mol of (NH₄)₂CO₃?

A. 1

B. 2

C. 3.01 × 10²³

D. 6.02 × 10²³

What is the value of x when 32.2 g of Na₂SO₄•xH₂O are heated leaving 14.2 g of anhydrous Na₂SO₄? M_r(H₂O) = 18; M_r(Na₂SO₄) = 142.

Na₂SO_4•xH₂O (s) → Na₂SO₄ (s) + xH₂O (g)

A. 0.1

B. 1

C. 5

D. 10

What is the value of x when 32.2 g of Na₂SO₄•xH₂O are heated leaving 14.2 g of anhydrous Na₂SO₄? M_r(H₂O) = 18; M_r(Na₂SO₄) = 142.

Na₂SO_4•xH₂O (s) → Na₂SO₄ (s) + xH₂O (g)

A. 0.1

B. 1

C. 5

D. 10

How many grams of sodium azide, NaN₃, are needed to produce 68.1 dm³ of N₂ (g) at STP?

Molar volume at STP = 22.7 dm³ mol^–1; M_r(NaN₃) = 65.0

2NaN₃ (s) → 3N₂ (g) + 2Na (s)

A. 32.5

B. 65.0

C. 130.0

D. 195.0

How many grams of sodium azide, NaN₃, are needed to produce 68.1 dm³ of N₂ (g) at STP?

Molar volume at STP = 22.7 dm³ mol^–1; M_r(NaN₃) = 65.0

2NaN₃ (s) → 3N₂ (g) + 2Na (s)

A. 32.5

B. 65.0

C. 130.0

D. 195.0

What is the sum of the coefficients when the following equation is balanced using the smallest whole numbers?

__C₆H₁₂O₆ (aq) → __C₂H₅OH (aq) + __CO₂ (g)

A. 4

B. 5

C. 9

D. 10

What is the sum of the coefficients when the following equation is balanced using the smallest whole numbers?

__C₆H₁₂O₆ (aq) → __C₂H₅OH (aq) + __CO₂ (g)

A. 4

B. 5

C. 9

D. 10

Which is the electron configuration of a chromium atom in the ground state?

A. [Ne]3s²3p⁶4s¹3d⁴

B. [Ar]3d³

C. 1s²2s²2p⁶3s²3p⁶4s²3d⁴

D. [Ar]4s¹3d⁵

Which is the electron configuration of a chromium atom in the ground state?

A. [Ne]3s²3p⁶4s¹3d⁴

B. [Ar]3d³

C. 1s²2s²2p⁶3s²3p⁶4s²3d⁴

D. [Ar]4s¹3d⁵

Which trends are correct across period 3 (from Na to Cl)?

I.   Atomic radius decreases
II.  Melting point increases
III. First ionization energy increases

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

Which trends are correct across period 3 (from Na to Cl)?

I.   Atomic radius decreases
II.  Melting point increases
III. First ionization energy increases

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

Consider the following half-equations:

I₂ (s) + 2e^– $\rightleftharpoons$ 2I^– (aq)                 E^θ = +0.54 V
(brown)          (colourless)

MnO₄^– (aq) + 8H⁺ (aq) + 5e^– $\rightleftharpoons$ Mn²⁺ (aq) + 4H₂O (l)                 E^θ = +1.51 V
(purple)                                      (colourless)                                                         

Which statement is correct for the reaction between KMnO₄ (aq) and KI (aq) in acidic conditions?

A. MnO₄^– reduces I^– to I₂.

B. I^– reduces MnO₄^– to Mn²⁺.

C. The colour changes from brown to purple.

D. MnO₄^– is oxidized to Mn²⁺.

Consider the following half-equations:

I₂ (s) + 2e^– $\rightleftharpoons$ 2I^– (aq)                 E^θ = +0.54 V
(brown)          (colourless)

MnO₄^– (aq) + 8H⁺ (aq) + 5e^– $\rightleftharpoons$ Mn²⁺ (aq) + 4H₂O (l)                 E^θ = +1.51 V
(purple)                                      (colourless)                                                         

Which statement is correct for the reaction between KMnO₄ (aq) and KI (aq) in acidic conditions?

A. MnO₄^– reduces I^– to I₂.

B. I^– reduces MnO₄^– to Mn²⁺.

C. The colour changes from brown to purple.

D. MnO₄^– is oxidized to Mn²⁺.

Which compound has the shortest C–N bond?

A. CH₃NH₂

B. (CH₃)₃CNH₂

C. CH₃CN

D. CH₃CHNH

Which compound has the shortest C–N bond?

A. CH₃NH₂

B. (CH₃)₃CNH₂

C. CH₃CN

D. CH₃CHNH

Which statement is correct for this reaction?

Fe₂O₃ (s) + 3CO (g) → 2Fe (s) + 3CO₂ (g)       ΔH = −26.6 kJ

A. 13.3 kJ are released for every mole of Fe produced.

B. 26.6 kJ are absorbed for every mole of Fe produced.

C. 53.2 kJ are released for every mole of Fe produced.

D. 26.6 kJ are released for every mole of Fe produced.

Sketch a graph that would support the student’s hypothesis.

Sketch a graph that would support the student’s hypothesis.

Sketch a graph that would support the student’s hypothesis.

Which statement is correct for this reaction?

Fe₂O₃ (s) + 3CO (g) → 2Fe (s) + 3CO₂ (g)       ΔH = −26.6 kJ

A. 13.3 kJ are released for every mole of Fe produced.

B. 26.6 kJ are absorbed for every mole of Fe produced.

C. 53.2 kJ are released for every mole of Fe produced.

D. 26.6 kJ are released for every mole of Fe produced.

Calculate the concentration of ethanoic acid, CH₃COOH, in mol dm^–3.

The enthalpy changes for two reactions are given.

Br₂ (l) + F₂ (g) → 2BrF (g)         ΔH = x kJ
Br₂ (l) + 3F₂ (g) → 2BrF₃ (g)      ΔH = y kJ

What is the enthalpy change for the following reaction?

BrF (g) + F₂ (g) → BrF₃ (g)

A.  x – y

B.  –x + y

C.  $\frac{1}{2}$(–x + y)

D.  $\frac{1}{2}$(x – y)

Calculate the concentration of ethanoic acid, CH₃COOH, in mol dm^–3.

Calculate the concentration of ethanoic acid, CH₃COOH, in mol dm^–3.

Determine the heat change, q, in kJ, for the neutralization reaction between ethanoic acid and sodium hydroxide.

Assume the specific heat capacities of the solutions and their densities are those of water.

The enthalpy changes for two reactions are given.

Br₂ (l) + F₂ (g) → 2BrF (g)         ΔH = x kJ
Br₂ (l) + 3F₂ (g) → 2BrF₃ (g)      ΔH = y kJ

What is the enthalpy change for the following reaction?

BrF (g) + F₂ (g) → BrF₃ (g)

A.  x – y

B.  –x + y

C.  $\frac{1}{2}$(–x + y)

D.  $\frac{1}{2}$(x – y)

Determine the heat change, q, in kJ, for the neutralization reaction between ethanoic acid and sodium hydroxide.

Assume the specific heat capacities of the solutions and their densities are those of water.

Determine the heat change, q, in kJ, for the neutralization reaction between ethanoic acid and sodium hydroxide.

Assume the specific heat capacities of the solutions and their densities are those of water.

What is the enthalpy change, in kJ, of the following reaction?

3H₂ (g) + N₂ (g) $\rightleftharpoons$ 2NH₃ (g)

A. (6 × 391) − [(3 × 436) + 945]

B. (3 × 391) − (436 + 945)

C. −[(3 × 436) + 945] + (3 × 391)

D. −(6 × 391) + [(3 × 436) + 945]

State an equation for the reaction of magnesium hydroxide with hydrochloric acid.

What is the enthalpy change, in kJ, of the following reaction?

3H₂ (g) + N₂ (g) $\rightleftharpoons$ 2NH₃ (g)

A. (6 × 391) − [(3 × 436) + 945]

B. (3 × 391) − (436 + 945)

C. −[(3 × 436) + 945] + (3 × 391)

D. −(6 × 391) + [(3 × 436) + 945]

State an equation for the reaction of magnesium hydroxide with hydrochloric acid.

State an equation for the reaction of magnesium hydroxide with hydrochloric acid.

Calculate the enthalpy change, ΔH, in kJ mol^–1, for the reaction between ethanoic acid and sodium hydroxide.

Calculate the enthalpy change, ΔH, in kJ mol^–1, for the reaction between ethanoic acid and sodium hydroxide.

Calculate the enthalpy change, ΔH, in kJ mol^–1, for the reaction between ethanoic acid and sodium hydroxide.

Suggest two variables, besides the time of reaction, which the student should have controlled in the experiment to ensure a fair comparison of the antacids.

Suggest two variables, besides the time of reaction, which the student should have controlled in the experiment to ensure a fair comparison of the antacids.

Suggest two variables, besides the time of reaction, which the student should have controlled in the experiment to ensure a fair comparison of the antacids.

Calculate the uncertainty in the change in pH.

Calculate the uncertainty in the change in pH.

Calculate the uncertainty in the change in pH.

Excess magnesium powder was added to a beaker containing hydrochloric acid, HCl (aq).

The mass of the beaker and its contents was recorded and plotted against time (line I).

Which change could give line II?

A. Doubling the mass of powdered Mg

B. Using the same mass of Mg ribbon

C. Increasing the temperature

D. Using the same volume of more concentrated HCl

Excess magnesium powder was added to a beaker containing hydrochloric acid, HCl (aq).

The mass of the beaker and its contents was recorded and plotted against time (line I).

Which change could give line II?

A. Doubling the mass of powdered Mg

B. Using the same mass of Mg ribbon

C. Increasing the temperature

D. Using the same volume of more concentrated HCl

Calculate the percentage of water by mass in the NaCl•2H₂O crystals. Use the data from section 6 of the data booklet and give your answer to two decimal places.

Calculate the percentage of water by mass in the NaCl•2H₂O crystals. Use the data from section 6 of the data booklet and give your answer to two decimal places.

Calculate the percentage of water by mass in the NaCl•2H₂O crystals. Use the data from section 6 of the data booklet and give your answer to two decimal places.

What will happen if the pressure is increased in the following reaction mixture at equilibrium?

CO₂ (g) + H₂O (l) $\rightleftharpoons$ H⁺ (aq) + HCO₃⁻ (aq)

A. The equilibrium will shift to the right and pH will decrease.

B. The equilibrium will shift to the right and pH will increase.

C. The equilibrium will shift to the left and pH will increase.

D. The equilibrium will shift to the left and pH will decrease.

Describe how the structures of LDPE and HDPE affect one mechanical property of the plastics.

Describe how the structures of LDPE and HDPE affect one mechanical property of the plastics.

Describe how the structures of LDPE and HDPE affect one mechanical property of the plastics.

One of the two infrared (IR) spectra is that of polyethene and the other of polytetrafluoroethene (PTFE).

Deduce, with a reason, which spectrum is that of PTFE. Infrared data is given in section 26 of the data booklet.

One of the two infrared (IR) spectra is that of polyethene and the other of polytetrafluoroethene (PTFE).

Deduce, with a reason, which spectrum is that of PTFE. Infrared data is given in section 26 of the data booklet.

One of the two infrared (IR) spectra is that of polyethene and the other of polytetrafluoroethene (PTFE).

Deduce, with a reason, which spectrum is that of PTFE. Infrared data is given in section 26 of the data booklet.

What will happen if the pressure is increased in the following reaction mixture at equilibrium?

CO₂ (g) + H₂O (l) $\rightleftharpoons$ H⁺ (aq) + HCO₃⁻ (aq)

A. The equilibrium will shift to the right and pH will decrease.

B. The equilibrium will shift to the right and pH will increase.

C. The equilibrium will shift to the left and pH will increase.

D. The equilibrium will shift to the left and pH will decrease.

Explain how the inclusion of carbohydrates in plastics makes them biodegradable.

Explain how the inclusion of carbohydrates in plastics makes them biodegradable.

Explain how the inclusion of carbohydrates in plastics makes them biodegradable.

Explain, at the molecular level, why vitamin D is soluble in fats. Use section 35 of the data booklet.

Explain, at the molecular level, why vitamin D is soluble in fats. Use section 35 of the data booklet.

Explain, at the molecular level, why vitamin D is soluble in fats. Use section 35 of the data booklet.

Explain why the melting points of the group 1 metals (Li → Cs) decrease down the group.

Identify the type of intermolecular bonding that is responsible for Kevlar^®’s strength.

Identify the type of intermolecular bonding that is responsible for Kevlar^®’s strength.

Identify the type of intermolecular bonding that is responsible for Kevlar^®’s strength.

Deduce which spectrum belongs to paracetamol, giving two reasons for your choice. Use section 26 of the data booklet.

Deduce which spectrum belongs to paracetamol, giving two reasons for your choice. Use section 26 of the data booklet.

Deduce which spectrum belongs to paracetamol, giving two reasons for your choice. Use section 26 of the data booklet.

Which statement is incorrect for a 0.10 mol dm^–3 HCOOH solution?

A. pH = 1

B. [H⁺] << 0.10 mol dm^–3

C. [HCOO^–] is approximately equal to [H⁺]

D. HCOOH is partially ionized

Explain why the melting points of the group 1 metals (Li → Cs) decrease down the group.

Explain why the melting points of the group 1 metals (Li → Cs) decrease down the group.

Which statement is incorrect for a 0.10 mol dm^–3 HCOOH solution?

A. pH = 1

B. [H⁺] << 0.10 mol dm^–3

C. [HCOO^–] is approximately equal to [H⁺]

D. HCOOH is partially ionized

State an equation for the reaction of phosphorus (V) oxide, P₄O₁₀ (s), with water.

What are the oxidation states of chromium in (NH₄)₂Cr₂O₇ (s) and Cr₂O₃ (s)?

State an equation for the reaction of phosphorus (V) oxide, P₄O₁₀ (s), with water.

State an equation for the reaction of phosphorus (V) oxide, P₄O₁₀ (s), with water.

What are the oxidation states of chromium in (NH₄)₂Cr₂O₇ (s) and Cr₂O₃ (s)?

Which of the following is a redox reaction?

A. 3Mg (s) + 2AlCl₃ (aq) → 2Al (s) + 3MgCl₂ (aq)

B. SiO₂ (s) + 2NaOH (aq) → Na₂SiO₃ (aq) + H₂O (l)

C. KCl (aq) + AgNO₃ (aq) → AgCl (s) + KNO₃ (aq)

D. 2NaHCO₃ (aq) → Na₂CO₃ (aq) + CO₂ (g) + H₂O (l)

What is the effect of increasing the temperature in this reaction?

CO₂(g) + H₂O(l) $\rightleftharpoons$ H⁺(aq) + HCO₃⁻(aq)     ΔH < 0

A.     The pH will decrease.

B.     The pH will increase.

C.     CO₂ pressure will decrease.

D.     The equilibrium position will shift to the right.

Which of the following is a redox reaction?

A. 3Mg (s) + 2AlCl₃ (aq) → 2Al (s) + 3MgCl₂ (aq)

B. SiO₂ (s) + 2NaOH (aq) → Na₂SiO₃ (aq) + H₂O (l)

C. KCl (aq) + AgNO₃ (aq) → AgCl (s) + KNO₃ (aq)

D. 2NaHCO₃ (aq) → Na₂CO₃ (aq) + CO₂ (g) + H₂O (l)

What is the effect of increasing the temperature in this reaction?

CO₂(g) + H₂O(l) $\rightleftharpoons$ H⁺(aq) + HCO₃⁻(aq)     ΔH < 0

A.     The pH will decrease.

B.     The pH will increase.

C.     CO₂ pressure will decrease.

D.     The equilibrium position will shift to the right.

What is the reaction type and major product at the anode (positive electrode) when molten sodium chloride is electrolysed using platinum electrodes?

What is the reaction type and major product at the anode (positive electrode) when molten sodium chloride is electrolysed using platinum electrodes?

A voltaic cell is made up of a Mn²⁺/Mn half-cell and a Ni²⁺/Ni half-cell.

Deduce the equation for the cell reaction.

A voltaic cell is made up of a Mn²⁺/Mn half-cell and a Ni²⁺/Ni half-cell.

Deduce the equation for the cell reaction.

A voltaic cell is made up of a Mn²⁺/Mn half-cell and a Ni²⁺/Ni half-cell.

Deduce the equation for the cell reaction.

Which compound can be oxidized when heated with an acidified solution of potassium dichromate(VI)?

A. CH₃C(O)CH₂CH₃

B. CH₃CH₂CH(OH)CH₃

C. (CH₃)₃COH

D. CH₃(CH₂)₂COOH

Which compound can be oxidized when heated with an acidified solution of potassium dichromate(VI)?

A. CH₃C(O)CH₂CH₃

B. CH₃CH₂CH(OH)CH₃

C. (CH₃)₃COH

D. CH₃(CH₂)₂COOH

The voltaic cell stated in part (ii) is partially shown below.

Draw and label the connections needed to show the direction of electron movement and ion flow between the two half-cells.

The voltaic cell stated in part (ii) is partially shown below.

Draw and label the connections needed to show the direction of electron movement and ion flow between the two half-cells.

The voltaic cell stated in part (ii) is partially shown below.

Draw and label the connections needed to show the direction of electron movement and ion flow between the two half-cells.

Calculate the percentage by mass of nitrogen in urea to two decimal places using section 6 of the data booklet.

Draw the Lewis (electron dot) structures of PF₃ and PF₄⁺ and use the VSEPR theory to deduce the molecular geometry of each species.

Draw the Lewis (electron dot) structures of PF₃ and PF₄⁺ and use the VSEPR theory to deduce the molecular geometry of each species.

Draw the Lewis (electron dot) structures of PF₃ and PF₄⁺ and use the VSEPR theory to deduce the molecular geometry of each species.

Predict with a reason, whether the molecule PF₃ is polar or non-polar.

Predict with a reason, whether the molecule PF₃ is polar or non-polar.

Predict with a reason, whether the molecule PF₃ is polar or non-polar.

Calculate the percentage by mass of nitrogen in urea to two decimal places using section 6 of the data booklet.

Calculate the percentage by mass of nitrogen in urea to two decimal places using section 6 of the data booklet.

What information is provided by ¹H NMR, MS and IR for an organic compound?

I.   ¹H NMR: chemical environment(s) of protons
II.  MS: fragmentation pattern
III. IR: types of functional group

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

The structural formula of urea is shown.

Predict the electron domain and molecular geometries at the nitrogen and carbon atoms, applying the VSEPR theory.

Complete combustion of 0.1595 g of menthol produces 0.4490 g of carbon dioxide and 0.1840 g of water. Determine the empirical formula of the compound showing your working.

What information is provided by ¹H NMR, MS and IR for an organic compound?

I.   ¹H NMR: chemical environment(s) of protons
II.  MS: fragmentation pattern
III. IR: types of functional group

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

The structural formula of urea is shown.

Predict the electron domain and molecular geometries at the nitrogen and carbon atoms, applying the VSEPR theory.

The structural formula of urea is shown.

Predict the electron domain and molecular geometries at the nitrogen and carbon atoms, applying the VSEPR theory.

Complete combustion of 0.1595 g of menthol produces 0.4490 g of carbon dioxide and 0.1840 g of water. Determine the empirical formula of the compound showing your working.

Complete combustion of 0.1595 g of menthol produces 0.4490 g of carbon dioxide and 0.1840 g of water. Determine the empirical formula of the compound showing your working.

0.150 g sample of menthol, when vaporized, had a volume of 0.0337 dm³ at 150 °C and 100.2 kPa. Calculate its molar mass showing your working.

Urea can be made by reacting potassium cyanate, KNCO, with ammonium chloride, NH₄Cl.

KNCO(aq) + NH₄Cl(aq) → (H₂N)₂CO(aq) + KCl(aq)

Determine the maximum mass of urea that could be formed from 50.0 cm³ of 0.100 mol dm⁻³ potassium cyanate solution.

Which solution neutralizes 50.0 cm³ of 0.120 mol dm^–3 NaOH (aq)?

A. 12.5 cm³ of 0.080 mol dm^–3 H₃PO₄

B. 25.0 cm³ of 0.120 mol dm^–3 CH₃COOH

C. 25.0 cm³ of 0.120 mol dm^–3 H₂SO₄

D. 50.0 cm³ of 0.060 mol dm^–3 HNO₃

Urea can be made by reacting potassium cyanate, KNCO, with ammonium chloride, NH₄Cl.

KNCO(aq) + NH₄Cl(aq) → (H₂N)₂CO(aq) + KCl(aq)

Determine the maximum mass of urea that could be formed from 50.0 cm³ of 0.100 mol dm⁻³ potassium cyanate solution.

Urea can be made by reacting potassium cyanate, KNCO, with ammonium chloride, NH₄Cl.

KNCO(aq) + NH₄Cl(aq) → (H₂N)₂CO(aq) + KCl(aq)

Determine the maximum mass of urea that could be formed from 50.0 cm³ of 0.100 mol dm⁻³ potassium cyanate solution.

0.150 g sample of menthol, when vaporized, had a volume of 0.0337 dm³ at 150 °C and 100.2 kPa. Calculate its molar mass showing your working.

0.150 g sample of menthol, when vaporized, had a volume of 0.0337 dm³ at 150 °C and 100.2 kPa. Calculate its molar mass showing your working.

Which solution neutralizes 50.0 cm³ of 0.120 mol dm^–3 NaOH (aq)?

A. 12.5 cm³ of 0.080 mol dm^–3 H₃PO₄

B. 25.0 cm³ of 0.120 mol dm^–3 CH₃COOH

C. 25.0 cm³ of 0.120 mol dm^–3 H₂SO₄

D. 50.0 cm³ of 0.060 mol dm^–3 HNO₃

The following reaction was allowed to reach equilibrium at 761 K.

H₂ (g) + I₂ (g) $\rightleftharpoons$ 2HI (g)               ΔH^θ < 0

Outline the effect, if any, of each of the following changes on the position of equilibrium, giving a reason in each case.

State the equilibrium constant expression, K_c.

State the equilibrium constant expression, K_c.

State the equilibrium constant expression, K_c.

What is the pressure, in Pa, inside a 1.0 m³ cylinder containing 10 kg of H₂ (g) at 25 ºC?

R = 8.31 J K^–1 mol^–1; pV = nRT

A. $\frac{1\times {10}^4\times 8.31\times 25}{1.0\times {10}^3}$

B. $\frac{5\times {10}^2\times 8.31\times 298}{1.0}$

C. $\frac{1\times 8.31\times 25}{1.0\times {10}^3}$

D. $\frac{5\times {10}^3\times 8.31\times 298}{1.0}$

Predict, with a reason, the effect on the equilibrium constant, K_c, when the temperature is increased.

The following reaction was allowed to reach equilibrium at 761 K.

H₂ (g) + I₂ (g) $\rightleftharpoons$ 2HI (g)               ΔH^θ < 0

Outline the effect, if any, of each of the following changes on the position of equilibrium, giving a reason in each case.

The following reaction was allowed to reach equilibrium at 761 K.

H₂ (g) + I₂ (g) $\rightleftharpoons$ 2HI (g)               ΔH^θ < 0

Outline the effect, if any, of each of the following changes on the position of equilibrium, giving a reason in each case.

What is the pressure, in Pa, inside a 1.0 m³ cylinder containing 10 kg of H₂ (g) at 25 ºC?

R = 8.31 J K^–1 mol^–1; pV = nRT

A. $\frac{1\times {10}^4\times 8.31\times 25}{1.0\times {10}^3}$

B. $\frac{5\times {10}^2\times 8.31\times 298}{1.0}$

C. $\frac{1\times 8.31\times 25}{1.0\times {10}^3}$

D. $\frac{5\times {10}^3\times 8.31\times 298}{1.0}$

Predict, with a reason, the effect on the equilibrium constant, K_c, when the temperature is increased.

Predict, with a reason, the effect on the equilibrium constant, K_c, when the temperature is increased.

Suggest one reason why urea is a solid and ammonia a gas at room temperature.

Suggest one reason why urea is a solid and ammonia a gas at room temperature.

Suggest one reason why urea is a solid and ammonia a gas at room temperature.

Sketch two different hydrogen bonding interactions between ammonia and water.

Which electron configuration is that of a transition metal atom in the ground state?

A. [Ne]3s²3p⁶4s¹

B. [Ar]3d⁹

C. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p²

D. [Ar]4s¹3d⁵

Sketch two different hydrogen bonding interactions between ammonia and water.

Sketch two different hydrogen bonding interactions between ammonia and water.

A student working in the laboratory classified HNO₃, H₂SO₄, H₃PO₄ and HClO₄ as acids based on their pH. He hypothesized that “all acids contain oxygen and hydrogen”.

Evaluate his hypothesis.

Which electron configuration is that of a transition metal atom in the ground state?

A. [Ne]3s²3p⁶4s¹

B. [Ar]3d⁹

C. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p²

D. [Ar]4s¹3d⁵

A student working in the laboratory classified HNO₃, H₂SO₄, H₃PO₄ and HClO₄ as acids based on their pH. He hypothesized that “all acids contain oxygen and hydrogen”.

Evaluate his hypothesis.

A student working in the laboratory classified HNO₃, H₂SO₄, H₃PO₄ and HClO₄ as acids based on their pH. He hypothesized that “all acids contain oxygen and hydrogen”.

Evaluate his hypothesis.

The combustion of urea produces water, carbon dioxide and nitrogen.

Formulate a balanced equation for the reaction.

The combustion of glucose is exothermic and occurs according to the following equation:

C₆H₁₂O₆ (s) + 6O₂ (g) → 6CO₂ (g) + 6H₂O (g)

Which is correct for this reaction?

The combustion of urea produces water, carbon dioxide and nitrogen.

Formulate a balanced equation for the reaction.

The combustion of urea produces water, carbon dioxide and nitrogen.

Formulate a balanced equation for the reaction.

Deduce the type of chemical reaction and the reagents used to distinguish between these compounds.

The combustion of glucose is exothermic and occurs according to the following equation:

C₆H₁₂O₆ (s) + 6O₂ (g) → 6CO₂ (g) + 6H₂O (g)

Which is correct for this reaction?

Deduce the type of chemical reaction and the reagents used to distinguish between these compounds.

Deduce the type of chemical reaction and the reagents used to distinguish between these compounds.

State the observation expected for each reaction giving your reasons.

Calculate the maximum volume of CO₂, in cm³, produced at STP by the combustion of 0.600 g of urea, using sections 2 and 6 of the data booklet.

Calculate the maximum volume of CO₂, in cm³, produced at STP by the combustion of 0.600 g of urea, using sections 2 and 6 of the data booklet.

Calculate the maximum volume of CO₂, in cm³, produced at STP by the combustion of 0.600 g of urea, using sections 2 and 6 of the data booklet.

State the observation expected for each reaction giving your reasons.

State the observation expected for each reaction giving your reasons.

Explain, with the help of equations, the mechanism of the free-radical substitution reaction of ethane with bromine in presence of sunlight.

The mass spectrum of urea is shown below.

Identify the species responsible for the peaks at m/z = 60 and 44.

The mass spectrum of urea is shown below.

Identify the species responsible for the peaks at m/z = 60 and 44.

The mass spectrum of urea is shown below.

Identify the species responsible for the peaks at m/z = 60 and 44.

Draw the best fit line for the reaction excluding point D.

The IR spectrum of urea is shown below.

Identify the bonds causing the absorptions at 3450 cm⁻¹ and 1700 cm⁻¹ using section 26 of the data booklet.

Explain, with the help of equations, the mechanism of the free-radical substitution reaction of ethane with bromine in presence of sunlight.

Explain, with the help of equations, the mechanism of the free-radical substitution reaction of ethane with bromine in presence of sunlight.

Draw the best fit line for the reaction excluding point D.

The IR spectrum of urea is shown below.

Identify the bonds causing the absorptions at 3450 cm⁻¹ and 1700 cm⁻¹ using section 26 of the data booklet.

The IR spectrum of urea is shown below.

Identify the bonds causing the absorptions at 3450 cm⁻¹ and 1700 cm⁻¹ using section 26 of the data booklet.

Draw the best fit line for the reaction excluding point D.

Suggest the relationship that points A, B and C show between the concentration of the acid and the rate of reaction.

Predict the number of signals in the ¹H NMR spectrum of urea.

Suggest the relationship that points A, B and C show between the concentration of the acid and the rate of reaction.

Predict the number of signals in the ¹H NMR spectrum of urea.

Predict the number of signals in the ¹H NMR spectrum of urea.

Suggest the relationship that points A, B and C show between the concentration of the acid and the rate of reaction.

Predict from your line of best fit the rate of reaction when the concentration of HCl is 1.00 mol dm⁻³.

Predict from your line of best fit the rate of reaction when the concentration of HCl is 1.00 mol dm⁻³.

Predict from your line of best fit the rate of reaction when the concentration of HCl is 1.00 mol dm⁻³.

Describe the nature of ionic bonding.

Predict, giving a reason, a difference between the reactions of the same concentrations of hydrochloric acid and ethanoic acid with samples of calcium carbonate.

Describe the nature of ionic bonding.

Describe the nature of ionic bonding.

Predict, giving a reason, a difference between the reactions of the same concentrations of hydrochloric acid and ethanoic acid with samples of calcium carbonate.

A sample of magnesium has the following isotopic composition.

Calculate the relative atomic mass of magnesium based on this data, giving your answer to two decimal places.

Predict, giving a reason, a difference between the reactions of the same concentrations of hydrochloric acid and ethanoic acid with samples of calcium carbonate.

Dissolved carbon dioxide causes unpolluted rain to have a pH of approximately 5, but other dissolved gases can result in a much lower pH. State one environmental effect of acid rain.

Describe how the relative atomic mass of a sample of calcium could be determined from its mass spectrum.

Dissolved carbon dioxide causes unpolluted rain to have a pH of approximately 5, but other dissolved gases can result in a much lower pH. State one environmental effect of acid rain.

Describe how the relative atomic mass of a sample of calcium could be determined from its mass spectrum.

Describe how the relative atomic mass of a sample of calcium could be determined from its mass spectrum.

A sample of magnesium has the following isotopic composition.

Calculate the relative atomic mass of magnesium based on this data, giving your answer to two decimal places.

A sample of magnesium has the following isotopic composition.

Calculate the relative atomic mass of magnesium based on this data, giving your answer to two decimal places.

Dissolved carbon dioxide causes unpolluted rain to have a pH of approximately 5, but other dissolved gases can result in a much lower pH. State one environmental effect of acid rain.

Write an equation to show ammonia, NH₃, acting as a Brønsted–Lowry base and a different equation to show it acting as a Lewis base.

Complete combustion of 0.1595 g of menthol produces 0.4490 g of carbon dioxide and 0.1840 g of water. Determine the empirical formula of the compound showing your working.

When calcium compounds are introduced into a gas flame a red colour is seen; sodium compounds give a yellow flame. Outline the source of the colours and why they are different.

Write an equation to show ammonia, NH₃, acting as a Brønsted–Lowry base and a different equation to show it acting as a Lewis base.

Write an equation to show ammonia, NH₃, acting as a Brønsted–Lowry base and a different equation to show it acting as a Lewis base.

Identify the missing component of the cell and its function.

When calcium compounds are introduced into a gas flame a red colour is seen; sodium compounds give a yellow flame. Outline the source of the colours and why they are different.

When calcium compounds are introduced into a gas flame a red colour is seen; sodium compounds give a yellow flame. Outline the source of the colours and why they are different.

Complete combustion of 0.1595 g of menthol produces 0.4490 g of carbon dioxide and 0.1840 g of water. Determine the empirical formula of the compound showing your working.

Complete combustion of 0.1595 g of menthol produces 0.4490 g of carbon dioxide and 0.1840 g of water. Determine the empirical formula of the compound showing your working.

0.150 g sample of menthol, when vaporized, had a volume of 0.0337 dm³ at 150 °C and 100.2 kPa. Calculate its molar mass showing your working.

Identify the missing component of the cell and its function.

Suggest two reasons why solid calcium has a greater density than solid potassium.

Identify the missing component of the cell and its function.

Deduce the half-equations for the reaction at each electrode when current flows.

Suggest two reasons why solid calcium has a greater density than solid potassium.

Suggest two reasons why solid calcium has a greater density than solid potassium.

0.150 g sample of menthol, when vaporized, had a volume of 0.0337 dm³ at 150 °C and 100.2 kPa. Calculate its molar mass showing your working.

0.150 g sample of menthol, when vaporized, had a volume of 0.0337 dm³ at 150 °C and 100.2 kPa. Calculate its molar mass showing your working.

Deduce the half-equations for the reaction at each electrode when current flows.

Deduce the half-equations for the reaction at each electrode when current flows.

Annotate the diagram with the location and direction of electron movement when current flows.

Determine the molecular formula of menthol using your answers from parts (d)(i) and (ii).

Outline why solid calcium is a good conductor of electricity.

Annotate the diagram with the location and direction of electron movement when current flows.

Outline why solid calcium is a good conductor of electricity.

Outline why solid calcium is a good conductor of electricity.

Annotate the diagram with the location and direction of electron movement when current flows.

State the organic product of the reaction between 1-chlorobutane, CH₃CH₂CH₂CH₂Cl, and aqueous sodium hydroxide.

Calcium carbide reacts with water to form ethyne and calcium hydroxide.

CaC₂(s) + H₂O(l) → C₂H₂(g) + Ca(OH)₂(aq)

Estimate the pH of the resultant solution.

Determine the molecular formula of menthol using your answers from parts (d)(i) and (ii).

Determine the molecular formula of menthol using your answers from parts (d)(i) and (ii).

State the organic product of the reaction between 1-chlorobutane, CH₃CH₂CH₂CH₂Cl, and aqueous sodium hydroxide.

State the organic product of the reaction between 1-chlorobutane, CH₃CH₂CH₂CH₂Cl, and aqueous sodium hydroxide.

Deduce the name of the class of compound formed when the product of (c)(i) reacts with butanoic acid.

Explain why the melting points of the group 1 metals (Li → Cs) decrease down the group whereas the melting points of the group 17 elements (F → I) increase down the group.

Calcium carbide reacts with water to form ethyne and calcium hydroxide.

CaC₂(s) + H₂O(l) → C₂H₂(g) + Ca(OH)₂(aq)

Estimate the pH of the resultant solution.

Calcium carbide reacts with water to form ethyne and calcium hydroxide.

CaC₂(s) + H₂O(l) → C₂H₂(g) + Ca(OH)₂(aq)

Estimate the pH of the resultant solution.

Deduce the name of the class of compound formed when the product of (c)(i) reacts with butanoic acid.

Deduce the name of the class of compound formed when the product of (c)(i) reacts with butanoic acid.

What occurs when the pressure on the given equilibrium is increased at constant temperature?

N₂(g) + O₂(g) $\rightleftharpoons$ 2NO(g)     ΔH = +180 kJ

A.     K_c increases and the position of equilibrium moves to the right.

B.     K_c stays the same and the position of equilibrium is unchanged.

C.     K_c stays the same and the position of equilibrium moves to the left.

D.     K_c decreases and the position of equilibrium moves to the left.

Ethyne, like ethene, undergoes hydrogenation to form ethane. State the conditions required.

Ethyne, like ethene, undergoes hydrogenation to form ethane. State the conditions required.

Ethyne, like ethene, undergoes hydrogenation to form ethane. State the conditions required.

Outline the formation of polyethene from ethene by drawing three repeating units of the polymer.

Outline the formation of polyethene from ethene by drawing three repeating units of the polymer.

Outline the formation of polyethene from ethene by drawing three repeating units of the polymer.

Explain why the melting points of the group 1 metals (Li → Cs) decrease down the group whereas the melting points of the group 17 elements (F → I) increase down the group.

Explain why the melting points of the group 1 metals (Li → Cs) decrease down the group whereas the melting points of the group 17 elements (F → I) increase down the group.

Draw the Lewis (electron dot) structures of PF₃ and PF₅ and use the VSEPR theory to deduce the molecular geometry of each species including bond angles.

Draw the Lewis (electron dot) structures of PF₃ and PF₅ and use the VSEPR theory to deduce the molecular geometry of each species including bond angles.

Draw the Lewis (electron dot) structures of PF₃ and PF₅ and use the VSEPR theory to deduce the molecular geometry of each species including bond angles.

Ethyne reacts with chlorine in a similar way to ethene. Formulate equations for the following reactions.

What occurs when the pressure on the given equilibrium is increased at constant temperature?

N₂(g) + O₂(g) $\rightleftharpoons$ 2NO(g)     ΔH = +180 kJ

A.     K_c increases and the position of equilibrium moves to the right.

B.     K_c stays the same and the position of equilibrium is unchanged.

C.     K_c stays the same and the position of equilibrium moves to the left.

D.     K_c decreases and the position of equilibrium moves to the left.

Ethyne reacts with chlorine in a similar way to ethene. Formulate equations for the following reactions.

Ethyne reacts with chlorine in a similar way to ethene. Formulate equations for the following reactions.

Under certain conditions, ethyne can be converted to benzene.

Determine the standard enthalpy change, ΔH^Θ, for the reaction stated, using section 11 of the data booklet.

3C₂H₂(g) → C₆H₆(g)

Predict whether the molecules PF₃ and PF₅ are polar or non-polar.

Predict whether the molecules PF₃ and PF₅ are polar or non-polar.

Predict whether the molecules PF₃ and PF₅ are polar or non-polar.

Calculate the standard enthalpy change for this reaction using the following data.

Calculate the standard enthalpy change for this reaction using the following data.

Calculate the standard enthalpy change for this reaction using the following data.

Under certain conditions, ethyne can be converted to benzene.

Determine the standard enthalpy change, ΔH^Θ, for the reaction stated, using section 11 of the data booklet.

3C₂H₂(g) → C₆H₆(g)

Under certain conditions, ethyne can be converted to benzene.

Determine the standard enthalpy change, ΔH^Θ, for the reaction stated, using section 11 of the data booklet.

3C₂H₂(g) → C₆H₆(g)

Determine the standard enthalpy change, ΔH^Θ, for the following similar reaction, using ΔH_f values in section 12 of the data booklet.

3C₂H₂(g) → C₆H₆(l)

Determine the standard enthalpy change, ΔH^Θ, for the following similar reaction, using ΔH_f values in section 12 of the data booklet.

3C₂H₂(g) → C₆H₆(l)

Determine the standard enthalpy change, ΔH^Θ, for the following similar reaction, using ΔH_f values in section 12 of the data booklet.

3C₂H₂(g) → C₆H₆(l)

Explain, giving two reasons, the difference in the values for (c)(i) and (ii). If you did not obtain answers, use −475 kJ for (i) and −600 kJ for (ii).

Outline why repeating quantitative measurements is important.

Explain, giving two reasons, the difference in the values for (c)(i) and (ii). If you did not obtain answers, use −475 kJ for (i) and −600 kJ for (ii).

Explain, giving two reasons, the difference in the values for (c)(i) and (ii). If you did not obtain answers, use −475 kJ for (i) and −600 kJ for (ii).

State the equilibrium constant expression, K_c , for this reaction.

Outline why repeating quantitative measurements is important.

One possible Lewis structure for benzene is shown.

State one piece of physical evidence that this structure is incorrect.

Outline why repeating quantitative measurements is important.

Outline, using an equation, why sodium ethanoate is basic.

One possible Lewis structure for benzene is shown.

State one piece of physical evidence that this structure is incorrect.

One possible Lewis structure for benzene is shown.

State one piece of physical evidence that this structure is incorrect.

State the equilibrium constant expression, K_c , for this reaction.

State the equilibrium constant expression, K_c , for this reaction.

Outline, using an equation, why sodium ethanoate is basic.

Deduce a balanced equation for the overall reaction when the standard nickel and iodine half-cells are connected.

Outline two ways in which the progress of the reaction can be monitored. No practical details are required.

Outline, using an equation, why sodium ethanoate is basic.

Formulate the equation for the reaction of nitrogen dioxide, NO₂, with water to form two acids.

Outline two ways in which the progress of the reaction can be monitored. No practical details are required.

Outline two ways in which the progress of the reaction can be monitored. No practical details are required.

Suggest why point D is so far out of line assuming human error is not the cause.

Deduce a balanced equation for the overall reaction when the standard nickel and iodine half-cells are connected.

Deduce a balanced equation for the overall reaction when the standard nickel and iodine half-cells are connected.

Formulate the equation for the reaction of nitrogen dioxide, NO₂, with water to form two acids.

Predict, giving a reason, the direction of movement of electrons when the standard nickel and manganese half-cells are connected.

Predict, giving a reason, the direction of movement of electrons when the standard nickel and manganese half-cells are connected.

Predict, giving a reason, the direction of movement of electrons when the standard nickel and manganese half-cells are connected.

Suggest why point D is so far out of line assuming human error is not the cause.

Suggest why point D is so far out of line assuming human error is not the cause.

Formulate the equation for the reaction of nitrogen dioxide, NO₂, with water to form two acids.

Formulate the equation for the reaction of one of the acids produced in (e)(i) with calcium carbonate.

Identify the best reducing agent in the table above.

Formulate the equation for the reaction of one of the acids produced in (e)(i) with calcium carbonate.

Identify the best reducing agent in the table above.

Identify the best reducing agent in the table above.

Formulate the equation for the reaction of one of the acids produced in (e)(i) with calcium carbonate.

Calculate the wavelength, in m, for the electron transition corresponding to the frequency in (a)(iii) using section 1 of the data booklet.

Calculate the wavelength, in m, for the electron transition corresponding to the frequency in (a)(iii) using section 1 of the data booklet.

Calculate the wavelength, in m, for the electron transition corresponding to the frequency in (a)(iii) using section 1 of the data booklet.

Deduce any change in the colour of the electrolyte during electrolysis.

Deduce any change in the colour of the electrolyte during electrolysis.

Deduce any change in the colour of the electrolyte during electrolysis.

In acidic solution, bromate ions, BrO₃⁻(aq), oxidize iodide ions, I⁻(aq).

BrO₃⁻(aq) + 6H⁺(aq) + 6e⁻ $\rightleftharpoons$ Br⁻(aq) + 3H₂O(l)

2I⁻(aq) $\rightleftharpoons$ I₂(s) + 2e⁻

Formulate the equation for the redox reaction.

In acidic solution, bromate ions, BrO₃⁻(aq), oxidize iodide ions, I⁻(aq).

BrO₃⁻(aq) + 6H⁺(aq) + 6e⁻ $\rightleftharpoons$ Br⁻(aq) + 3H₂O(l)

2I⁻(aq) $\rightleftharpoons$ I₂(s) + 2e⁻

Formulate the equation for the redox reaction.

In acidic solution, bromate ions, BrO₃⁻(aq), oxidize iodide ions, I⁻(aq).

BrO₃⁻(aq) + 6H⁺(aq) + 6e⁻ $\rightleftharpoons$ Br⁻(aq) + 3H₂O(l)

2I⁻(aq) $\rightleftharpoons$ I₂(s) + 2e⁻

Formulate the equation for the redox reaction.

What are the strongest intermolecular forces between molecules of propanone, CH₃COCH₃, in the liquid phase?

A.     London (dispersion) forces

B.     Covalent bonding

C.     Hydrogen bonding

D.     Dipole–dipole forces

What are the strongest intermolecular forces between molecules of propanone, CH₃COCH₃, in the liquid phase?

A.     London (dispersion) forces

B.     Covalent bonding

C.     Hydrogen bonding

D.     Dipole–dipole forces

Hydrogen gas can be formed industrially by the reaction of natural gas with steam.

                                          CH₄(g) + H₂O(g) → 3H₂(g) + CO(g)

Determine the enthalpy change, ΔH, for the reaction, in kJ, using section 11 of the data booklet.

Bond enthalpy for C≡O: 1077 kJ mol⁻¹

Hydrogen gas can be formed industrially by the reaction of natural gas with steam.

                                          CH₄(g) + H₂O(g) → 3H₂(g) + CO(g)

Determine the enthalpy change, ΔH, for the reaction, in kJ, using section 11 of the data booklet.

Bond enthalpy for C≡O: 1077 kJ mol⁻¹

Hydrogen gas can be formed industrially by the reaction of natural gas with steam.

                                          CH₄(g) + H₂O(g) → 3H₂(g) + CO(g)

Determine the enthalpy change, ΔH, for the reaction, in kJ, using section 11 of the data booklet.

Bond enthalpy for C≡O: 1077 kJ mol⁻¹

Outline why no value is listed for H₂(g).

Outline why no value is listed for H₂(g).

Outline why no value is listed for H₂(g).

Determine the value of ΔH^Θ, in kJ, for the reaction using the values in the table.

Determine the value of ΔH^Θ, in kJ, for the reaction using the values in the table.

Determine the value of ΔH^Θ, in kJ, for the reaction using the values in the table.

What is the enthalpy of combustion of butane in kJ mol⁻¹?

2C₄H₁₀(g) + 13O₂(g) → 8CO₂(g) + 10H₂O(l)

A.     4x + 5y − z 

B.     4x + 5y + z 

C.     8x + 10y − 2z 

D.     8x + 5y + 2z

What is the enthalpy of combustion of butane in kJ mol⁻¹?

2C₄H₁₀(g) + 13O₂(g) → 8CO₂(g) + 10H₂O(l)

A.     4x + 5y − z 

B.     4x + 5y + z 

C.     8x + 10y − 2z 

D.     8x + 5y + 2z

Nitrogen oxide is in equilibrium with dinitrogen dioxide.

2NO(g) $\rightleftharpoons$ N₂O₂(g)     ΔH^Θ < 0

Deduce, giving a reason, the effect of increasing the temperature on the concentration of N₂O₂.

Nitrogen oxide is in equilibrium with dinitrogen dioxide.

2NO(g) $\rightleftharpoons$ N₂O₂(g)     ΔH^Θ < 0

Deduce, giving a reason, the effect of increasing the temperature on the concentration of N₂O₂.

Nitrogen oxide is in equilibrium with dinitrogen dioxide.

2NO(g) $\rightleftharpoons$ N₂O₂(g)     ΔH^Θ < 0

Deduce, giving a reason, the effect of increasing the temperature on the concentration of N₂O₂.

Carbon and silicon are elements in group 14.

Explain why CO₂ is a gas but SiO₂ is a solid at room temperature.

Carbon and silicon are elements in group 14.

Explain why CO₂ is a gas but SiO₂ is a solid at room temperature.

Carbon and silicon are elements in group 14.

Explain why CO₂ is a gas but SiO₂ is a solid at room temperature.

What is the percentage yield when 7 g of ethene produces 6 g of ethanol?

M_r(ethene) = 28 and M_r(ethanol) = 46

C₂H₄(g) + H₂O(g) → C₂H₅OH(g)

A.     $\frac{6\times 7\times 100}{28\times 46}$

B.     $\frac{6\times 46\times 100}{7\times 28}$

C.     $\frac{6\times 28}{7\times 46\times 100}$

D.     $\frac{6\times 28\times 100}{7\times 46}$

Which change increases the rate of formation of hydrogen when zinc reacts with excess hydrochloric acid, assuming all other conditions remain the same?

Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)

A.     Adding water to the hydrochloric acid

B.     Decreasing the temperature

C.     Increasing the volume of hydrochloric acid

D.     Decreasing the size of the zinc particles while keeping the total mass of zinc the same

Which change increases the rate of formation of hydrogen when zinc reacts with excess hydrochloric acid, assuming all other conditions remain the same?

Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)

A.     Adding water to the hydrochloric acid

B.     Decreasing the temperature

C.     Increasing the volume of hydrochloric acid

D.     Decreasing the size of the zinc particles while keeping the total mass of zinc the same

Deduce the structural formulas of the two possible isomers.

Deduce the structural formulas of the two possible isomers.

Deduce the structural formulas of the two possible isomers.

What is the percentage yield when 7 g of ethene produces 6 g of ethanol?

M_r(ethene) = 28 and M_r(ethanol) = 46

C₂H₄(g) + H₂O(g) → C₂H₅OH(g)

A.     $\frac{6\times 7\times 100}{28\times 46}$

B.     $\frac{6\times 46\times 100}{7\times 28}$

C.     $\frac{6\times 28}{7\times 46\times 100}$

D.     $\frac{6\times 28\times 100}{7\times 46}$

Natural uranium needs to be enriched to increase the proportion of ²³⁵U. Suggest a technique that would determine the relative abundances of ²³⁵U and ²³⁸U.

Natural uranium needs to be enriched to increase the proportion of ²³⁵U. Suggest a technique that would determine the relative abundances of ²³⁵U and ²³⁸U.

Natural uranium needs to be enriched to increase the proportion of ²³⁵U. Suggest a technique that would determine the relative abundances of ²³⁵U and ²³⁸U.

The equilibrium constant for N₂(g) + 3H₂(g) $\rightleftharpoons$ 2NH₃(g) is K.

What is the equilibrium constant for this equation?

2N₂(g) + 6H₂(g) $\rightleftharpoons$ 4NH₃(g)

A.     K

B.     2K

C.     K²

D.     2K²

The equilibrium constant for N₂(g) + 3H₂(g) $\rightleftharpoons$ 2NH₃(g) is K.

What is the equilibrium constant for this equation?

2N₂(g) + 6H₂(g) $\rightleftharpoons$ 4NH₃(g)

A.     K

B.     2K

C.     K²

D.     2K²

What is the sum of the coefficients when the equation is balanced with the lowest whole number ratio?

__Na₂S₂O₃(aq) + __HCl(aq) → __S(s) + __SO₂(g) + __NaCl(aq) + __H₂O(l)

A.     6

B.     7

C.     8

D.     9

What is the sum of the coefficients when the equation is balanced with the lowest whole number ratio?

__Na₂S₂O₃(aq) + __HCl(aq) → __S(s) + __SO₂(g) + __NaCl(aq) + __H₂O(l)

A.     6

B.     7

C.     8

D.     9

Which classification is correct for the reaction?

H₂PO₄⁻(aq) + H₂O(l) → HPO₄²⁻(aq) + H₃O⁺(aq)

Which classification is correct for the reaction?

H₂PO₄⁻(aq) + H₂O(l) → HPO₄²⁻(aq) + H₃O⁺(aq)

What is the volume, in cm³, of the final solution if 100 cm³ of a solution containing 1.42 g of sodium sulfate, Na₂SO₄, is diluted to the concentration of 0.020 mol dm^–3?

M_r(Na₂SO₄) = 142

A.     50

B.     400

C.     500

D.     600

What is the volume, in cm³, of the final solution if 100 cm³ of a solution containing 1.42 g of sodium sulfate, Na₂SO₄, is diluted to the concentration of 0.020 mol dm^–3?

M_r(Na₂SO₄) = 142

A.     50

B.     400

C.     500

D.     600

What is the percentage yield when 2.0 g of ethene, C₂H₄, is formed from 5.0 g of ethanol, C₂H₅OH?
M_r(ethene) = 28; M_r(ethanol) = 46

A.     $\frac{2.0}{28}\times \frac{5.0}{46}\times 100$

B.     $\frac{\frac{2.0}{28}}{\frac{5.0}{46}}\times 100$

C.     $\frac{28}{2.0}\times \frac{5.0}{46}\times 100$

D.     $\frac{\frac{28}{2.0}}{\frac{5.0}{46}}\times 100$

What is the percentage yield when 2.0 g of ethene, C₂H₄, is formed from 5.0 g of ethanol, C₂H₅OH?
M_r(ethene) = 28; M_r(ethanol) = 46

A.     $\frac{2.0}{28}\times \frac{5.0}{46}\times 100$

B.     $\frac{\frac{2.0}{28}}{\frac{5.0}{46}}\times 100$

C.     $\frac{28}{2.0}\times \frac{5.0}{46}\times 100$

D.     $\frac{\frac{28}{2.0}}{\frac{5.0}{46}}\times 100$

Which equation shows oxygen undergoing reduction?

A.     2F₂ + O₂ → 2F₂O

B.     Na₂O + H₂O → 2NaOH

C.     H₂O₂ + 2HI → 2H₂O + I₂

D.     2CrO₄²⁻ + 2H⁺ $\rightleftharpoons$ Cr₂O₇²⁻ + H₂O

Which equation shows oxygen undergoing reduction?

A.     2F₂ + O₂ → 2F₂O

B.     Na₂O + H₂O → 2NaOH

C.     H₂O₂ + 2HI → 2H₂O + I₂

D.     2CrO₄²⁻ + 2H⁺ $\rightleftharpoons$ Cr₂O₇²⁻ + H₂O

Which coefficients correctly balance this redox equation?

aFe²⁺(aq) + MnO₄⁻(aq) + bH⁺(aq) → cFe³⁺(aq) + Mn²⁺(aq) + dH₂O(l)

Which coefficients correctly balance this redox equation?

aFe²⁺(aq) + MnO₄⁻(aq) + bH⁺(aq) → cFe³⁺(aq) + Mn²⁺(aq) + dH₂O(l)

What is the formula of ammonium phosphate?

A.     (NH₃)₃PO₄

B.     (NH₄)₃PO₄

C.     (NH₄)₂PO₄

D.     (NH₃)₂PO₃

What is the formula of ammonium phosphate?

A.     (NH₃)₃PO₄

B.     (NH₄)₃PO₄

C.     (NH₄)₂PO₄

D.     (NH₃)₂PO₃

Activity series of selected elements:

$$\text{greatest activity}\stackrel{\text{K, Ca, Al, Fe, H, Cu, Ag, Au}}{\leftarrow }\text{least activity}$$

Which react with dilute sulfuric acid?

       I.     Cu

       II.     CuO

       III.     CuCO₃

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

Which compound could be formed when CH₃CH₂CH₂OH is heated with acidified potassium dichromate(VI)?

        I.     CH₃CH₂CHO

        II.     CH₃CH₂COOH

        III.     CH₃COCH₃

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

Which compound could be formed when CH₃CH₂CH₂OH is heated with acidified potassium dichromate(VI)?

        I.     CH₃CH₂CHO

        II.     CH₃CH₂COOH

        III.     CH₃COCH₃

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

Activity series of selected elements:

$$\text{greatest activity}\stackrel{\text{K, Ca, Al, Fe, H, Cu, Ag, Au}}{\leftarrow }\text{least activity}$$

Which react with dilute sulfuric acid?

       I.     Cu

       II.     CuO

       III.     CuCO₃

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

Calculate the percentage by mass of nitrogen in urea to two decimal places using section 6 of the data booklet.

What are the predicted electron domain geometries around the carbon and both nitrogen atoms in urea, (NH₂)₂CO, applying VSEPR theory?

What are the predicted electron domain geometries around the carbon and both nitrogen atoms in urea, (NH₂)₂CO, applying VSEPR theory?

The compounds shown below have similar relative molecular masses. What is the correct order of increasing boiling point?

A.     CH₃COOH < (CH₃)₂CO < (CH₃)₂CHOH

B.     CH₃COOH < (CH₃)₂CHOH < (CH₃)₂CO

C.     (CH₃)₂CO < CH₃COOH < (CH₃)₂CHOH

D.     (CH₃)₂CO < (CH₃)₂CHOH < CH₃COOH

The compounds shown below have similar relative molecular masses. What is the correct order of increasing boiling point?

A.     CH₃COOH < (CH₃)₂CO < (CH₃)₂CHOH

B.     CH₃COOH < (CH₃)₂CHOH < (CH₃)₂CO

C.     (CH₃)₂CO < CH₃COOH < (CH₃)₂CHOH

D.     (CH₃)₂CO < (CH₃)₂CHOH < CH₃COOH

Calculate the percentage by mass of nitrogen in urea to two decimal places using section 6 of the data booklet.

Calculate the percentage by mass of nitrogen in urea to two decimal places using section 6 of the data booklet.

What is the enthalpy change of combustion of urea, (NH₂)₂CO, in kJ mol⁻¹?

2(NH₂)₂CO(s) + 3O₂(g) → 2CO₂(g) + 2N₂(g) + 4H₂O(l)

A.     2 × (−333) −2 × (−394) −4 × (−286)

B.     $\frac{1}{2}$[2 × (−394) + 4 × (−286) −2 × (−333)]

C.     2 × (−394) + 4 × (−286) −2 × (−333)

D.     $\frac{1}{2}$[2 × (−333) −2 × (−394) −4 × (−286)]

What is the enthalpy change of combustion of urea, (NH₂)₂CO, in kJ mol⁻¹?

2(NH₂)₂CO(s) + 3O₂(g) → 2CO₂(g) + 2N₂(g) + 4H₂O(l)

A.     2 × (−333) −2 × (−394) −4 × (−286)

B.     $\frac{1}{2}$[2 × (−394) + 4 × (−286) −2 × (−333)]

C.     2 × (−394) + 4 × (−286) −2 × (−333)

D.     $\frac{1}{2}$[2 × (−333) −2 × (−394) −4 × (−286)]

The structural formula of urea is shown.

Predict the electron domain and molecular geometries at the nitrogen and carbon atoms, applying the VSEPR theory.

The structural formula of urea is shown.

Predict the electron domain and molecular geometries at the nitrogen and carbon atoms, applying the VSEPR theory.

The structural formula of urea is shown.

Predict the electron domain and molecular geometries at the nitrogen and carbon atoms, applying the VSEPR theory.

Two 100 cm³ aqueous solutions, one containing 0.010 mol NaOH and the other 0.010 mol HCl, are at the same temperature.

When the two solutions are mixed the temperature rises by y °C.

Assume the density of the final solution is 1.00 g cm⁻³.

Specific heat capacity of water = 4.18 J g⁻¹ K⁻¹

What is the enthalpy change of neutralization in kJ mol⁻¹?

A.     $\frac{200\times 4.18\times y}{1000\times 0.020}$

B.     $\frac{200\times 4.18\times y}{1000\times 0.010}$

C.     $\frac{100\times 4.18\times y}{1000\times 0.010}$

D.     $\frac{200\times 4.18\times (y+273)}{1000\times 0.010}$

Two 100 cm³ aqueous solutions, one containing 0.010 mol NaOH and the other 0.010 mol HCl, are at the same temperature.

When the two solutions are mixed the temperature rises by y °C.

Assume the density of the final solution is 1.00 g cm⁻³.

Specific heat capacity of water = 4.18 J g⁻¹ K⁻¹

What is the enthalpy change of neutralization in kJ mol⁻¹?

A.     $\frac{200\times 4.18\times y}{1000\times 0.020}$

B.     $\frac{200\times 4.18\times y}{1000\times 0.010}$

C.     $\frac{100\times 4.18\times y}{1000\times 0.010}$

D.     $\frac{200\times 4.18\times (y+273)}{1000\times 0.010}$

The potential energy profile for the reversible reaction, X + Y ƒ$\rightleftharpoons$ Z is shown.

Which arrow represents the activation energy for the reverse reaction, Z → X + Y, with a catalyst?

Urea can be made by reacting potassium cyanate, KNCO, with ammonium chloride, NH₄Cl.

                                      KNCO(aq) + NH₄Cl(aq) → (H₂N)₂CO(aq) + KCl(aq)

Determine the maximum mass of urea that could be formed from 50.0 cm³ of 0.100 mol dm⁻³ potassium cyanate solution.

Urea can be made by reacting potassium cyanate, KNCO, with ammonium chloride, NH₄Cl.

                                      KNCO(aq) + NH₄Cl(aq) → (H₂N)₂CO(aq) + KCl(aq)

Determine the maximum mass of urea that could be formed from 50.0 cm³ of 0.100 mol dm⁻³ potassium cyanate solution.

Urea can be made by reacting potassium cyanate, KNCO, with ammonium chloride, NH₄Cl.

                                      KNCO(aq) + NH₄Cl(aq) → (H₂N)₂CO(aq) + KCl(aq)

Determine the maximum mass of urea that could be formed from 50.0 cm³ of 0.100 mol dm⁻³ potassium cyanate solution.

Urea can also be made by the direct combination of ammonia and carbon dioxide gases.

                                   2NH₃(g) + CO₂(g) $\rightleftharpoons$ (H₂N)₂CO(g) + H₂O(g)     ΔH < 0

Predict, with a reason, the effect on the equilibrium constant, K_c, when the temperature is increased.

The potential energy profile for the reversible reaction, X + Y ƒ$\rightleftharpoons$ Z is shown.

Which arrow represents the activation energy for the reverse reaction, Z → X + Y, with a catalyst?

Urea can also be made by the direct combination of ammonia and carbon dioxide gases.

                                   2NH₃(g) + CO₂(g) $\rightleftharpoons$ (H₂N)₂CO(g) + H₂O(g)     ΔH < 0

Predict, with a reason, the effect on the equilibrium constant, K_c, when the temperature is increased.

Urea can also be made by the direct combination of ammonia and carbon dioxide gases.

                                   2NH₃(g) + CO₂(g) $\rightleftharpoons$ (H₂N)₂CO(g) + H₂O(g)     ΔH < 0

Predict, with a reason, the effect on the equilibrium constant, K_c, when the temperature is increased.

Which factor does not affect the position of equilibrium in this reaction?

2NO₂(g) $\rightleftharpoons$ N₂O₄(g)     ΔH = −58 kJ mol⁻¹

A.     Change in volume of the container

B.     Change in temperature

C.     Addition of a catalyst

D.     Change in pressure

Suggest one reason why urea is a solid and ammonia a gas at room temperature.

Suggest one reason why urea is a solid and ammonia a gas at room temperature.

Suggest one reason why urea is a solid and ammonia a gas at room temperature.

Which factor does not affect the position of equilibrium in this reaction?

2NO₂(g) $\rightleftharpoons$ N₂O₄(g)     ΔH = −58 kJ mol⁻¹

A.     Change in volume of the container

B.     Change in temperature

C.     Addition of a catalyst

D.     Change in pressure

Deduce the number of ¹H NMR signals produced by the zwitterion form of alanine.

Deduce the number of ¹H NMR signals produced by the zwitterion form of alanine.

Deduce the number of ¹H NMR signals produced by the zwitterion form of alanine.

Sketch two different hydrogen bonding interactions between ammonia and water.

Explain why aspirin is not stored in a hot, humid location.

Explain why aspirin is not stored in a hot, humid location.

Explain why aspirin is not stored in a hot, humid location.

Sketch two different hydrogen bonding interactions between ammonia and water.

Sketch two different hydrogen bonding interactions between ammonia and water.

The combustion of urea produces water, carbon dioxide and nitrogen.

Formulate a balanced equation for the reaction.

The combustion of urea produces water, carbon dioxide and nitrogen.

Formulate a balanced equation for the reaction.

The combustion of urea produces water, carbon dioxide and nitrogen.

Formulate a balanced equation for the reaction.

Calculate the amount, in mol, of H₂SO₄.

The mass spectrum of urea is shown below.

Identify the species responsible for the peaks at m/z = 60 and 44.

The mass spectrum of urea is shown below.

Identify the species responsible for the peaks at m/z = 60 and 44.

The mass spectrum of urea is shown below.

Identify the species responsible for the peaks at m/z = 60 and 44.

Calculate the amount, in mol, of H₂SO₄.

The IR spectrum of urea is shown below.

Identify the bonds causing the absorptions at 3450 cm⁻¹ and 1700 cm⁻¹ using section 26 of the data booklet.

The IR spectrum of urea is shown below.

Identify the bonds causing the absorptions at 3450 cm⁻¹ and 1700 cm⁻¹ using section 26 of the data booklet.

The IR spectrum of urea is shown below.

Identify the bonds causing the absorptions at 3450 cm⁻¹ and 1700 cm⁻¹ using section 26 of the data booklet.

Calculate the amount, in mol, of H₂SO₄.

Formulate the equation for the reaction of H₂SO₄ with Mg(OH)₂.

Predict the number of signals in the ¹H NMR spectrum of urea.

How many moles of FeS₂ are required to produce 32 g of SO₂? (A_r: S = 32, O = 16)

4FeS₂ (s) + 11O₂ (g) → 2Fe₂O₃ (s) + 8SO₂ (g)

A.   0.25

B.   0.50

C.   1.0

D.   2.0

Formulate the equation for the reaction of H₂SO₄ with Mg(OH)₂.

Predict the number of signals in the ¹H NMR spectrum of urea.

Predict the number of signals in the ¹H NMR spectrum of urea.

Formulate the equation for the reaction of H₂SO₄ with Mg(OH)₂.

The excess sulfuric acid required 20.80 cm³ of 0.1133 mol dm⁻³ NaOH for neutralization.

Calculate the amount of excess acid present.

How many moles of FeS₂ are required to produce 32 g of SO₂? (A_r: S = 32, O = 16)

4FeS₂ (s) + 11O₂ (g) → 2Fe₂O₃ (s) + 8SO₂ (g)

A.   0.25

B.   0.50

C.   1.0

D.   2.0

Describe the nature of ionic bonding.

The excess sulfuric acid required 20.80 cm³ of 0.1133 mol dm⁻³ NaOH for neutralization.

Calculate the amount of excess acid present.

The excess sulfuric acid required 20.80 cm³ of 0.1133 mol dm⁻³ NaOH for neutralization.

Calculate the amount of excess acid present.

Calculate the amount of H₂SO₄ that reacted with Mg(OH)₂.

Describe the nature of ionic bonding.

Describe the nature of ionic bonding.

Calculate the amount of H₂SO₄ that reacted with Mg(OH)₂.

State the electron configuration of the Ca²⁺ ion.

Calculate the amount of H₂SO₄ that reacted with Mg(OH)₂.

Determine the mass of Mg(OH)₂ in the antacid tablet.

16 g of bromine react with 5.2 g of metal, M, to form MBr₂. What is the relative atomic mass of the metal M? (A_r : Br = 80)

A.   13

B.   26

C.   52

D.   104

State the electron configuration of the Ca²⁺ ion.

State the electron configuration of the Ca²⁺ ion.

Determine the mass of Mg(OH)₂ in the antacid tablet.

16 g of bromine react with 5.2 g of metal, M, to form MBr₂. What is the relative atomic mass of the metal M? (A_r : Br = 80)

A.   13

B.   26

C.   52

D.   104

Determine the mass of Mg(OH)₂ in the antacid tablet.

When calcium compounds are introduced into a gas flame a red colour is seen; sodium compounds give a yellow flame. Outline the source of the colours and why they are different.

Calculate the percentage by mass of magnesium hydroxide in the 1.24 g antacid tablet to three significant figures.

When calcium compounds are introduced into a gas flame a red colour is seen; sodium compounds give a yellow flame. Outline the source of the colours and why they are different.

When calcium compounds are introduced into a gas flame a red colour is seen; sodium compounds give a yellow flame. Outline the source of the colours and why they are different.

An antacid tablet containing 0.50 g of NaHCO₃ (M_r = 84) is dissolved in water to give a volume of 250 cm³. What is the concentration, in mol dm⁻³, of HCO₃⁻ in this solution?

A.   $\frac{0.250\times 84}{0.50}$

B.   $\frac{0.50}{84\times 0.250}$

C.   $\frac{250\times 84}{0.50}$

D.   $\frac{0.50}{84\times 250}$

Calculate the percentage by mass of magnesium hydroxide in the 1.24 g antacid tablet to three significant figures.

An antacid tablet containing 0.50 g of NaHCO₃ (M_r = 84) is dissolved in water to give a volume of 250 cm³. What is the concentration, in mol dm⁻³, of HCO₃⁻ in this solution?

A.   $\frac{0.250\times 84}{0.50}$

B.   $\frac{0.50}{84\times 0.250}$

C.   $\frac{250\times 84}{0.50}$

D.   $\frac{0.50}{84\times 250}$

Calculate the percentage by mass of magnesium hydroxide in the 1.24 g antacid tablet to three significant figures.

Sketch a Maxwell–Boltzmann distribution curve for a chemical reaction showing the activation energies with and without a catalyst.

Suggest two reasons why solid calcium has a greater density than solid potassium.

Sketch a Maxwell–Boltzmann distribution curve for a chemical reaction showing the activation energies with and without a catalyst.

Suggest two reasons why solid calcium has a greater density than solid potassium.

Suggest two reasons why solid calcium has a greater density than solid potassium.

Sketch a Maxwell–Boltzmann distribution curve for a chemical reaction showing the activation energies with and without a catalyst.

Sketch a curve on the graph to show the volume of gas produced over time if the same mass of crushed calcium carbonate is used instead of lumps. All other conditions remain constant.

Outline why solid calcium is a good conductor of electricity.

Sketch a curve on the graph to show the volume of gas produced over time if the same mass of crushed calcium carbonate is used instead of lumps. All other conditions remain constant.

Outline why solid calcium is a good conductor of electricity.

Outline why solid calcium is a good conductor of electricity.

Sketch a curve on the graph to show the volume of gas produced over time if the same mass of crushed calcium carbonate is used instead of lumps. All other conditions remain constant.

State and explain the effect on the rate of reaction if ethanoic acid of the same concentration is used in place of hydrochloric acid.

Calcium carbide reacts with water to form ethyne and calcium hydroxide.

CaC₂(s) + H₂O(l) → C₂H₂(g) + Ca(OH)₂(aq)

Estimate the pH of the resultant solution.

State and explain the effect on the rate of reaction if ethanoic acid of the same concentration is used in place of hydrochloric acid.

Calcium carbide reacts with water to form ethyne and calcium hydroxide.

CaC₂(s) + H₂O(l) → C₂H₂(g) + Ca(OH)₂(aq)

Estimate the pH of the resultant solution.

Calcium carbide reacts with water to form ethyne and calcium hydroxide.

CaC₂(s) + H₂O(l) → C₂H₂(g) + Ca(OH)₂(aq)

Estimate the pH of the resultant solution.

State and explain the effect on the rate of reaction if ethanoic acid of the same concentration is used in place of hydrochloric acid.

Outline why pH is more widely used than [H⁺] for measuring relative acidity.

Outline why pH is more widely used than [H⁺] for measuring relative acidity.

Ethyne, like ethene, undergoes hydrogenation to form ethane. State the conditions required.

Outline why pH is more widely used than [H⁺] for measuring relative acidity.

Outline why H₃PO₄/HPO₄²⁻ is not a conjugate acid-base pair.

Ethyne, like ethene, undergoes hydrogenation to form ethane. State the conditions required.

Ethyne, like ethene, undergoes hydrogenation to form ethane. State the conditions required.

Outline why H₃PO₄/HPO₄²⁻ is not a conjugate acid-base pair.

Outline the formation of polyethene from ethene by drawing three repeating units of the polymer.

Outline why H₃PO₄/HPO₄²⁻ is not a conjugate acid-base pair.

Draw the first four energy levels of a hydrogen atom on the axis, labelling n = 1, 2, 3 and 4.

Outline the formation of polyethene from ethene by drawing three repeating units of the polymer.

Outline the formation of polyethene from ethene by drawing three repeating units of the polymer.

Under certain conditions, ethyne can be converted to benzene.

Determine the standard enthalpy change, ΔH^ϴ, for the reaction stated, using section 11 of the data booklet.

                                        3C₂H₂(g) → C₆H₆(g)

Under certain conditions, ethyne can be converted to benzene.

Determine the standard enthalpy change, ΔH^ϴ, for the reaction stated, using section 11 of the data booklet.

                                        3C₂H₂(g) → C₆H₆(g)

Under certain conditions, ethyne can be converted to benzene.

Determine the standard enthalpy change, ΔH^ϴ, for the reaction stated, using section 11 of the data booklet.

                                        3C₂H₂(g) → C₆H₆(g)

Determine the standard enthalpy change, ΔH^Θ, for the following similar reaction, using ΔH_f values in section 12 of the data booklet.

3C₂H₂(g) → C₆H₆(l)

Determine the standard enthalpy change, ΔH^Θ, for the following similar reaction, using ΔH_f values in section 12 of the data booklet.

3C₂H₂(g) → C₆H₆(l)

Determine the standard enthalpy change, ΔH^Θ, for the following similar reaction, using ΔH_f values in section 12 of the data booklet.

3C₂H₂(g) → C₆H₆(l)

Explain, giving two reasons, the difference in the values for (b)(i) and (ii). If you did not obtain answers, use −475 kJ for (i) and −600 kJ for (ii).

Draw the first four energy levels of a hydrogen atom on the axis, labelling n = 1, 2, 3 and 4.

Explain, giving two reasons, the difference in the values for (b)(i) and (ii). If you did not obtain answers, use −475 kJ for (i) and −600 kJ for (ii).

Explain, giving two reasons, the difference in the values for (b)(i) and (ii). If you did not obtain answers, use −475 kJ for (i) and −600 kJ for (ii).

One possible Lewis structure for benzene is shown.

State one piece of physical evidence that this structure is incorrect.

One possible Lewis structure for benzene is shown.

State one piece of physical evidence that this structure is incorrect.

One possible Lewis structure for benzene is shown.

State one piece of physical evidence that this structure is incorrect.

Draw the first four energy levels of a hydrogen atom on the axis, labelling n = 1, 2, 3 and 4.

Draw the lines, on your diagram, that represent the electron transitions to n = 2 in the emission spectrum.

State the characteristic reaction mechanism of benzene.

State the characteristic reaction mechanism of benzene.

State the characteristic reaction mechanism of benzene.

Outline two ways in which the progress of the reaction can be monitored. No practical details are required.

Outline two ways in which the progress of the reaction can be monitored. No practical details are required.

Outline two ways in which the progress of the reaction can be monitored. No practical details are required.

Suggest why point D is so far out of line assuming human error is not the cause.

Suggest why point D is so far out of line assuming human error is not the cause.

Suggest why point D is so far out of line assuming human error is not the cause.

Draw the lines, on your diagram, that represent the electron transitions to n = 2 in the emission spectrum.

Suggest the relationship that points A, B and C show between the concentration of the acid and the rate of reaction.

Suggest the relationship that points A, B and C show between the concentration of the acid and the rate of reaction.

Suggest the relationship that points A, B and C show between the concentration of the acid and the rate of reaction.

Draw the lines, on your diagram, that represent the electron transitions to n = 2 in the emission spectrum.

Outline why atomic radius decreases across period 3, sodium to chlorine.

Predict, giving a reason, a difference between the reactions of the same concentrations of hydrochloric acid and ethanoic acid with samples of calcium carbonate.

Predict, giving a reason, a difference between the reactions of the same concentrations of hydrochloric acid and ethanoic acid with samples of calcium carbonate.

Predict, giving a reason, a difference between the reactions of the same concentrations of hydrochloric acid and ethanoic acid with samples of calcium carbonate.

Dissolved carbon dioxide causes unpolluted rain to have a pH of approximately 5, but other dissolved gases can result in a much lower pH. State one environmental effect of acid rain.

Outline why atomic radius decreases across period 3, sodium to chlorine.

Dissolved carbon dioxide causes unpolluted rain to have a pH of approximately 5, but other dissolved gases can result in a much lower pH. State one environmental effect of acid rain.

Dissolved carbon dioxide causes unpolluted rain to have a pH of approximately 5, but other dissolved gases can result in a much lower pH. State one environmental effect of acid rain.

Outline why atomic radius decreases across period 3, sodium to chlorine.

Outline why the ionic radius of K⁺ is smaller than that of Cl⁻.

Identify the missing component of the cell and its function.

Identify the missing component of the cell and its function.

Identify the missing component of the cell and its function.

Deduce the half-equations for the reaction at each electrode when current flows.

Outline why the ionic radius of K⁺ is smaller than that of Cl⁻.

Consider the following reactions:

Fe₂O₃ (s) + CO (g) → 2FeO (s) + CO₂ (g)       ΔH^Θ = −3 kJ

Fe (s) + CO₂ (g) → FeO (s) + CO (g)               ΔH^Θ = +11 kJ

What is the ΔH^Θ value, in kJ, for the following reaction?

Fe₂O₃ (s) + 3CO (g) → 2Fe (s) + 3CO₂ (g)

A.   −25

B.   −14

C.   +8

D.   +19

Deduce the half-equations for the reaction at each electrode when current flows.

Deduce the half-equations for the reaction at each electrode when current flows.

Outline why the ionic radius of K⁺ is smaller than that of Cl⁻.

Copper is widely used as an electrical conductor.

Draw arrows in the boxes to represent the electronic configuration of copper in the 4s and 3d orbitals.

Annotate the diagram with the location and direction of electron movement when current flows.

Annotate the diagram with the location and direction of electron movement when current flows.

Annotate the diagram with the location and direction of electron movement when current flows.

Part of this molecule is hydrophilic (bonds readily to water) and part hydrophobic (does not bond readily to water). Draw a circle around all of the hydrophilic part of the molecule.

Part of this molecule is hydrophilic (bonds readily to water) and part hydrophobic (does not bond readily to water). Draw a circle around all of the hydrophilic part of the molecule.

Part of this molecule is hydrophilic (bonds readily to water) and part hydrophobic (does not bond readily to water). Draw a circle around all of the hydrophilic part of the molecule.

When a small amount of palmitic acid is placed in water it disperses to form a layer on the surface that is only one molecule thick. Explain, in terms of intermolecular forces, why this occurs.

When a small amount of palmitic acid is placed in water it disperses to form a layer on the surface that is only one molecule thick. Explain, in terms of intermolecular forces, why this occurs.

When a small amount of palmitic acid is placed in water it disperses to form a layer on the surface that is only one molecule thick. Explain, in terms of intermolecular forces, why this occurs.

Suggest why there is a small increase in the surface pressure as the area is reduced to about 240 cm², but a much faster increase when it is further reduced.

Suggest why there is a small increase in the surface pressure as the area is reduced to about 240 cm², but a much faster increase when it is further reduced.

Suggest why there is a small increase in the surface pressure as the area is reduced to about 240 cm², but a much faster increase when it is further reduced.

Consider the following reactions:

Fe₂O₃ (s) + CO (g) → 2FeO (s) + CO₂ (g)       ΔH^Θ = −3 kJ

Fe (s) + CO₂ (g) → FeO (s) + CO (g)               ΔH^Θ = +11 kJ

What is the ΔH^Θ value, in kJ, for the following reaction?

Fe₂O₃ (s) + 3CO (g) → 2Fe (s) + 3CO₂ (g)

A.   −25

B.   −14

C.   +8

D.   +19

Which is correct when Ba(OH)₂ reacts with NH₄Cl?

Ba(OH)₂ (s) + 2NH₄Cl (s) → BaCl₂ (aq) + 2NH₃ (g) + 2H₂O (l)       ΔH^Θ = +164 kJ mol⁻¹

Which is correct when Ba(OH)₂ reacts with NH₄Cl?

Ba(OH)₂ (s) + 2NH₄Cl (s) → BaCl₂ (aq) + 2NH₃ (g) + 2H₂O (l)       ΔH^Θ = +164 kJ mol⁻¹

Copper is widely used as an electrical conductor.

Draw arrows in the boxes to represent the electronic configuration of copper in the 4s and 3d orbitals.

Consider the following reaction:

N₂ (g) + 3H₂ (g) $\rightleftharpoons$ 2NH₃ (g)

Which calculation gives ΔH^Θ, in kJ, for the forward reaction?

A.   2z − y − 3x

B.   y + 3x − 2z

C.   y + 3x − 6z

D.   6z − y − 3x

Consider the following reaction:

N₂ (g) + 3H₂ (g) $\rightleftharpoons$ 2NH₃ (g)

Which calculation gives ΔH^Θ, in kJ, for the forward reaction?

A.   2z − y − 3x

B.   y + 3x − 2z

C.   y + 3x − 6z

D.   6z − y − 3x

Samples of sodium carbonate powder were reacted with separate samples of excess hydrochloric acid.

Na₂CO₃ (s) + 2HCl (aq) → CO₂ (g) + 2NaCl (aq) + H₂O (l)

Reaction I: 1.0 g Na₂CO₃ (s) added to 0.50 mol dm⁻³ HCl (aq)

Reaction II: 1.0 g Na₂CO₃ (s) added to 2.0 mol dm⁻³ HCl (aq)

What is the same for reactions I and II?

A.   Initial rate of reaction

B.   Total mass of CO₂ produced

C.   Total reaction time

D.   Average rate of production of CO₂

The solution of palmitic acid had a concentration of 0.0034 mol dm⁻³. Calculate the number of molecules of palmitic acid present in the 0.050 cm³ drop, using section 2 of the data booklet.

The solution of palmitic acid had a concentration of 0.0034 mol dm⁻³. Calculate the number of molecules of palmitic acid present in the 0.050 cm³ drop, using section 2 of the data booklet.

The solution of palmitic acid had a concentration of 0.0034 mol dm⁻³. Calculate the number of molecules of palmitic acid present in the 0.050 cm³ drop, using section 2 of the data booklet.

Assuming the sudden change in gradient occurs at 240 cm², calculate the area, in cm², that a single molecule of palmitic acid occupies on surface of the water.

If you did not obtain an answer for (b)(ii) use a value of 8.2 × 10¹⁶, but this is not the correct answer.

Assuming the sudden change in gradient occurs at 240 cm², calculate the area, in cm², that a single molecule of palmitic acid occupies on surface of the water.

If you did not obtain an answer for (b)(ii) use a value of 8.2 × 10¹⁶, but this is not the correct answer.

Assuming the sudden change in gradient occurs at 240 cm², calculate the area, in cm², that a single molecule of palmitic acid occupies on surface of the water.

If you did not obtain an answer for (b)(ii) use a value of 8.2 × 10¹⁶, but this is not the correct answer.

Copper is widely used as an electrical conductor.

Draw arrows in the boxes to represent the electronic configuration of copper in the 4s and 3d orbitals.

Impure copper can be purified by electrolysis. In the electrolytic cell, impure copper is the anode (positive electrode), pure copper is the cathode (negative electrode) and the electrolyte is copper(II) sulfate solution.

Formulate the half-equation at each electrode.

Annotate the balanced equation below with state symbols.

CaCO₃(__) + 2HCl(__) → CaCl₂(__) + CO₂(__) + H₂O(__)

Annotate the balanced equation below with state symbols.

CaCO₃(__) + 2HCl(__) → CaCl₂(__) + CO₂(__) + H₂O(__)

Annotate the balanced equation below with state symbols.

CaCO₃(__) + 2HCl(__) → CaCl₂(__) + CO₂(__) + H₂O(__)

Neither method actually gives the initial rate. Outline a method that would allow the initial rate to be determined.

Samples of sodium carbonate powder were reacted with separate samples of excess hydrochloric acid.

Na₂CO₃ (s) + 2HCl (aq) → CO₂ (g) + 2NaCl (aq) + H₂O (l)

Reaction I: 1.0 g Na₂CO₃ (s) added to 0.50 mol dm⁻³ HCl (aq)

Reaction II: 1.0 g Na₂CO₃ (s) added to 2.0 mol dm⁻³ HCl (aq)

What is the same for reactions I and II?

A.   Initial rate of reaction

B.   Total mass of CO₂ produced

C.   Total reaction time

D.   Average rate of production of CO₂

Impure copper can be purified by electrolysis. In the electrolytic cell, impure copper is the anode (positive electrode), pure copper is the cathode (negative electrode) and the electrolyte is copper(II) sulfate solution.

Formulate the half-equation at each electrode.

Neither method actually gives the initial rate. Outline a method that would allow the initial rate to be determined.

Neither method actually gives the initial rate. Outline a method that would allow the initial rate to be determined.

Deduce, giving a reason, which of the two methods would be least affected by the chips not having exactly the same mass when used with the different concentrations of acid.

Deduce, giving a reason, which of the two methods would be least affected by the chips not having exactly the same mass when used with the different concentrations of acid.

Deduce, giving a reason, which of the two methods would be least affected by the chips not having exactly the same mass when used with the different concentrations of acid.

Impure copper can be purified by electrolysis. In the electrolytic cell, impure copper is the anode (positive electrode), pure copper is the cathode (negative electrode) and the electrolyte is copper(II) sulfate solution.

Formulate the half-equation at each electrode.

Outline where and in which direction the electrons flow during electrolysis.

State a factor, that has a significant effect on reaction rate, which could vary between marble chips of exactly the same mass.

State a factor, that has a significant effect on reaction rate, which could vary between marble chips of exactly the same mass.

State a factor, that has a significant effect on reaction rate, which could vary between marble chips of exactly the same mass.

Justify why it is inappropriate to record the uncertainty of the mean as ±0.01 s.

Consider the reaction:

2N₂O (g) $\rightleftharpoons$ 2N₂ (g) + O₂ (g)

The values of K_c at different temperatures are:

Which statement is correct at higher temperature?

A.   The forward reaction is favoured.

B.   The reverse reaction is favoured.

C.   The rate of the reverse reaction is greater than the rate of the forward reaction.

D.   The concentration of both reactants and products increase.

Outline where and in which direction the electrons flow during electrolysis.

Justify why it is inappropriate to record the uncertainty of the mean as ±0.01 s.

Justify why it is inappropriate to record the uncertainty of the mean as ±0.01 s.

If doubling the concentration doubles the reaction rate, suggest the mean time you would expect for the reaction with 2.00 mol dm⁻³ hydrochloric acid.

Outline where and in which direction the electrons flow during electrolysis.

Hydrogen gas can be formed industrially by the reaction of natural gas with steam.

                                          CH₄(g) + H₂O(g) → 3H₂(g) + CO(g)

Determine the enthalpy change, ΔH, for the reaction, in kJ, using section 11 of the data booklet.

Bond enthalpy for C≡O: 1077 kJ mol⁻¹

If doubling the concentration doubles the reaction rate, suggest the mean time you would expect for the reaction with 2.00 mol dm⁻³ hydrochloric acid.

If doubling the concentration doubles the reaction rate, suggest the mean time you would expect for the reaction with 2.00 mol dm⁻³ hydrochloric acid.

Another student, working alone, always dropped the marble chips into the acid and then picked up the stopwatch to start it. State, giving a reason, whether this introduced a random or systematic error.

Consider the reaction:

2N₂O (g) $\rightleftharpoons$ 2N₂ (g) + O₂ (g)

The values of K_c at different temperatures are:

Which statement is correct at higher temperature?

A.   The forward reaction is favoured.

B.   The reverse reaction is favoured.

C.   The rate of the reverse reaction is greater than the rate of the forward reaction.

D.   The concentration of both reactants and products increase.

Hydrogen gas can be formed industrially by the reaction of natural gas with steam.

                                          CH₄(g) + H₂O(g) → 3H₂(g) + CO(g)

Determine the enthalpy change, ΔH, for the reaction, in kJ, using section 11 of the data booklet.

Bond enthalpy for C≡O: 1077 kJ mol⁻¹

Which two species act as Brønsted–Lowry acids in the reaction?

H₂PO₄⁻ (aq) + OH⁻ (aq) $\rightleftharpoons$ HPO₄²⁻ (aq) + H₂O (l)

A. HPO₄²⁻ (aq) and OH⁻ (aq)

B. H₂PO₄⁻ (aq) and HPO₄²⁻ (aq)

C. HPO₄²⁻ (aq) and H₂O (l)

D. H₂PO₄⁻ (aq) and H₂O (l)

Another student, working alone, always dropped the marble chips into the acid and then picked up the stopwatch to start it. State, giving a reason, whether this introduced a random or systematic error.

Another student, working alone, always dropped the marble chips into the acid and then picked up the stopwatch to start it. State, giving a reason, whether this introduced a random or systematic error.

Hydrogen gas can be formed industrially by the reaction of natural gas with steam.

                                          CH₄(g) + H₂O(g) → 3H₂(g) + CO(g)

Determine the enthalpy change, ΔH, for the reaction, in kJ, using section 11 of the data booklet.

Bond enthalpy for C≡O: 1077 kJ mol⁻¹

Outline why no value is listed for H₂(g).

Outline why no value is listed for H₂(g).

Outline why no value is listed for H₂(g).

Determine the value of ΔH^Θ, in kJ, for the reaction using the values in the table.

Which two species act as Brønsted–Lowry acids in the reaction?

H₂PO₄⁻ (aq) + OH⁻ (aq) $\rightleftharpoons$ HPO₄²⁻ (aq) + H₂O (l)

A. HPO₄²⁻ (aq) and OH⁻ (aq)

B. H₂PO₄⁻ (aq) and HPO₄²⁻ (aq)

C. HPO₄²⁻ (aq) and H₂O (l)

D. H₂PO₄⁻ (aq) and H₂O (l)

Determine the value of ΔH^Θ, in kJ, for the reaction using the values in the table.

Determine the value of ΔH^Θ, in kJ, for the reaction using the values in the table.

Outline why the value of enthalpy of reaction calculated from bond enthalpies is less accurate.

What is the order of increasing pH for the following solutions of the same concentration?

A.   HCl (aq) < NH₃ (aq) < NaOH (aq) < CH₃COOH (aq)

B.   CH₃COOH (aq) < HCl (aq) < NH₃ (aq) < NaOH (aq)

C.   HCl (aq) < CH₃COOH (aq) < NH₃ (aq) < NaOH (aq)

D.   NaOH (aq) < NH₃ (aq) < CH₃COOH (aq) < HCl (aq)

Determine the limiting reactant showing your working.

Outline why the value of enthalpy of reaction calculated from bond enthalpies is less accurate.

Outline why the value of enthalpy of reaction calculated from bond enthalpies is less accurate.

Distinguish between the terms reaction quotient, Q, and equilibrium constant, K_c.

What is the order of increasing pH for the following solutions of the same concentration?

A.   HCl (aq) < NH₃ (aq) < NaOH (aq) < CH₃COOH (aq)

B.   CH₃COOH (aq) < HCl (aq) < NH₃ (aq) < NaOH (aq)

C.   HCl (aq) < CH₃COOH (aq) < NH₃ (aq) < NaOH (aq)

D.   NaOH (aq) < NH₃ (aq) < CH₃COOH (aq) < HCl (aq)

Distinguish between the terms reaction quotient, Q, and equilibrium constant, K_c.

Which is correct for the reaction?

P₄ (s) + 3H₂O (l) + 3OH⁻ (aq) → PH₃ (g) + 3H₂PO₂⁻ (aq)

Determine the limiting reactant showing your working.

Determine the limiting reactant showing your working.

Distinguish between the terms reaction quotient, Q, and equilibrium constant, K_c.

The equilibrium constant, K_c, is 0.282 at temperature T.

Deduce, showing your work, the direction of the initial reaction.

The equilibrium constant, K_c, is 0.282 at temperature T.

Deduce, showing your work, the direction of the initial reaction.

The mass of copper obtained experimentally was 0.872 g. Calculate the percentage yield of copper.

Which is correct for the reaction?

P₄ (s) + 3H₂O (l) + 3OH⁻ (aq) → PH₃ (g) + 3H₂PO₂⁻ (aq)

The equilibrium constant, K_c, is 0.282 at temperature T.

Deduce, showing your work, the direction of the initial reaction.

Explain why the hydrides of group 16 elements (H₂O, H₂S, H₂Se and H₂Te) are polar molecules.

Which describes the flow of electrons in a voltaic cell?

A.   From the cathode (positive electrode) to the anode (negative electrode) through the external circuit

B.   From the anode (negative electrode) to the cathode (positive electrode) through the external circuit

C.   From the oxidizing agent to the reducing agent through the salt bridge

D.   From the reducing agent to the oxidizing agent through the salt bridge

The mass of copper obtained experimentally was 0.872 g. Calculate the percentage yield of copper.

The mass of copper obtained experimentally was 0.872 g. Calculate the percentage yield of copper.

Explain why the hydrides of group 16 elements (H₂O, H₂S, H₂Se and H₂Te) are polar molecules.

Which describes the flow of electrons in a voltaic cell?

A.   From the cathode (positive electrode) to the anode (negative electrode) through the external circuit

B.   From the anode (negative electrode) to the cathode (positive electrode) through the external circuit

C.   From the oxidizing agent to the reducing agent through the salt bridge

D.   From the reducing agent to the oxidizing agent through the salt bridge

Explain why the hydrides of group 16 elements (H₂O, H₂S, H₂Se and H₂Te) are polar molecules.

The graph shows the boiling points of the hydrides of group 16 elements.

Explain the increase in the boiling point from H₂S to H₂Te.

The reaction was carried out in a calorimeter. The maximum temperature rise of the solution was 7.5 °C.

Calculate the enthalpy change, ΔH, of the reaction, in kJ, assuming that all the heat released was absorbed by the solution. Use sections 1 and 2 of the data booklet.

The graph shows the boiling points of the hydrides of group 16 elements.

Explain the increase in the boiling point from H₂S to H₂Te.

The graph shows the boiling points of the hydrides of group 16 elements.

Explain the increase in the boiling point from H₂S to H₂Te.

Lewis structures show electron domains and are used to predict molecular geometry.

Deduce the electron domain geometry and the molecular geometry for the NH₂⁻ ion.

Which compounds cause the colour of acidified potassium manganate(VII) solution to change from purple to colourless?

I.    CH₃CH₂CH₂CH₂OH

II.   (CH₃)₃CCH₂OH

III.  CH₃CH₂CH(OH)CH₃

A.   I and II only

B.   I and III only

C.   II and III only

D.   I, II and III

The reaction was carried out in a calorimeter. The maximum temperature rise of the solution was 7.5 °C.

Calculate the enthalpy change, ΔH, of the reaction, in kJ, assuming that all the heat released was absorbed by the solution. Use sections 1 and 2 of the data booklet.

The reaction was carried out in a calorimeter. The maximum temperature rise of the solution was 7.5 °C.

Calculate the enthalpy change, ΔH, of the reaction, in kJ, assuming that all the heat released was absorbed by the solution. Use sections 1 and 2 of the data booklet.

Lewis structures show electron domains and are used to predict molecular geometry.

Deduce the electron domain geometry and the molecular geometry for the NH₂⁻ ion.

Which compounds cause the colour of acidified potassium manganate(VII) solution to change from purple to colourless?

I.    CH₃CH₂CH₂CH₂OH

II.   (CH₃)₃CCH₂OH

III.  CH₃CH₂CH(OH)CH₃

A.   I and II only

B.   I and III only

C.   II and III only

D.   I, II and III

Lewis structures show electron domains and are used to predict molecular geometry.

Deduce the electron domain geometry and the molecular geometry for the NH₂⁻ ion.

The Kekulé structure of benzene suggests it should readily undergo addition reactions.

Discuss two pieces of evidence, one physical and one chemical, which suggest this is not the structure of benzene.

State another assumption you made in (b)(i).

The Kekulé structure of benzene suggests it should readily undergo addition reactions.

Discuss two pieces of evidence, one physical and one chemical, which suggest this is not the structure of benzene.

State another assumption you made in (b)(i).

State another assumption you made in (b)(i).

What is the order of increasing boiling point for the isomers of C₅H₁₂?

A.   CH₃CH₂CH₂CH₂CH₃ < CH₃CH(CH₃)CH₂CH₃ < CH₃C(CH₃)₃

B.   CH₃C(CH₃)₃ < CH₃CH(CH₃)CH₂CH₃ < CH₃CH₂CH₂CH₂CH₃

C.   CH₃C(CH₃)₃ < CH₃CH₂CH₂CH₂CH₃ < CH₃CH(CH₃)CH₂CH₃

D.   CH₃CH(CH₃)CH₂CH₃ < CH₃C(CH₃)₃ < CH₃CH₂CH₂CH₂CH₃

The Kekulé structure of benzene suggests it should readily undergo addition reactions.

Discuss two pieces of evidence, one physical and one chemical, which suggest this is not the structure of benzene.

Formulate the ionic equation for the oxidation of propan-1-ol to the corresponding aldehyde by acidified dichromate(VI) ions. Use section 24 of the data booklet.

What is the order of increasing boiling point for the isomers of C₅H₁₂?

A.   CH₃CH₂CH₂CH₂CH₃ < CH₃CH(CH₃)CH₂CH₃ < CH₃C(CH₃)₃

B.   CH₃C(CH₃)₃ < CH₃CH(CH₃)CH₂CH₃ < CH₃CH₂CH₂CH₂CH₃

C.   CH₃C(CH₃)₃ < CH₃CH₂CH₂CH₂CH₃ < CH₃CH(CH₃)CH₂CH₃

D.   CH₃CH(CH₃)CH₂CH₃ < CH₃C(CH₃)₃ < CH₃CH₂CH₂CH₂CH₃

The only significant uncertainty is in the temperature measurement.

Determine the absolute uncertainty in the calculated value of ΔH if the uncertainty in the temperature rise was ±0.2 °C.

Formulate the ionic equation for the oxidation of propan-1-ol to the corresponding aldehyde by acidified dichromate(VI) ions. Use section 24 of the data booklet.

Formulate the ionic equation for the oxidation of propan-1-ol to the corresponding aldehyde by acidified dichromate(VI) ions. Use section 24 of the data booklet.

The aldehyde can be further oxidized to a carboxylic acid.

Outline how the experimental procedures differ for the synthesis of the aldehyde and the carboxylic acid.

The only significant uncertainty is in the temperature measurement.

Determine the absolute uncertainty in the calculated value of ΔH if the uncertainty in the temperature rise was ±0.2 °C.

The only significant uncertainty is in the temperature measurement.

Determine the absolute uncertainty in the calculated value of ΔH if the uncertainty in the temperature rise was ±0.2 °C.

Which compounds react to form CH₃CH₂CH₂COOCH(CH₃)₂?

A.   propanoic acid and propan-2-ol

B.   propanoic acid and butan-2-ol

C.   butanoic acid and propan-1-ol

D.   butanoic acid and propan-2-ol

The aldehyde can be further oxidized to a carboxylic acid.

Outline how the experimental procedures differ for the synthesis of the aldehyde and the carboxylic acid.

Which compounds react to form CH₃CH₂CH₂COOCH(CH₃)₂?

A.   propanoic acid and propan-2-ol

B.   propanoic acid and butan-2-ol

C.   butanoic acid and propan-1-ol

D.   butanoic acid and propan-2-ol

Sketch a graph of the concentration of iron(II) sulfate, FeSO₄, against time as the reaction proceeds.

The aldehyde can be further oxidized to a carboxylic acid.

Outline how the experimental procedures differ for the synthesis of the aldehyde and the carboxylic acid.

Deduce the molecular formula of the compound.

Deduce the molecular formula of the compound.

Sketch a graph of the concentration of iron(II) sulfate, FeSO₄, against time as the reaction proceeds.

Sketch a graph of the concentration of iron(II) sulfate, FeSO₄, against time as the reaction proceeds.

Deduce the molecular formula of the compound.

Identify the bonds causing peaks A and B in the IR spectrum of the unknown compound using section 26 of the data booklet.

Identify the bonds causing peaks A and B in the IR spectrum of the unknown compound using section 26 of the data booklet.

Outline how the initial rate of reaction can be determined from the graph in part (c)(i).

Identify the bonds causing peaks A and B in the IR spectrum of the unknown compound using section 26 of the data booklet.

Deduce full structural formulas of two possible isomers of the unknown compound, both of which are esters.

Outline how the initial rate of reaction can be determined from the graph in part (c)(i).

Outline how the initial rate of reaction can be determined from the graph in part (c)(i).

Deduce full structural formulas of two possible isomers of the unknown compound, both of which are esters.

Deduce full structural formulas of two possible isomers of the unknown compound, both of which are esters.

Deduce the formula of the unknown compound based on its ¹H NMR spectrum using section 27 of the data booklet.

Deduce the formula of the unknown compound based on its ¹H NMR spectrum using section 27 of the data booklet.

Deduce the formula of the unknown compound based on its ¹H NMR spectrum using section 27 of the data booklet.

Graphene is two-dimensional, rather than three-dimensional, material.

Justify this by using the structure of graphene and information from the table.

Graphene is two-dimensional, rather than three-dimensional, material.

Justify this by using the structure of graphene and information from the table.

Graphene is two-dimensional, rather than three-dimensional, material.

Justify this by using the structure of graphene and information from the table.

Show that graphene is over 1600 times stronger than graphite.

Show that graphene is over 1600 times stronger than graphite.

Show that graphene is over 1600 times stronger than graphite.

Identify a value from the table which can be used to support the information about graphene given below.

Electrons in a solid are restricted to certain ranges, or bands, of energy (vertical axis). In an insulator or semiconductor, an electron bound to an atom can break free only if it gets enough energy from heat or a passing photon to jump the “band gap”, but in graphene the gap is infinitely small.

Identify a value from the table which can be used to support the information about graphene given below.

Electrons in a solid are restricted to certain ranges, or bands, of energy (vertical axis). In an insulator or semiconductor, an electron bound to an atom can break free only if it gets enough energy from heat or a passing photon to jump the “band gap”, but in graphene the gap is infinitely small.

Identify a value from the table which can be used to support the information about graphene given below.

Electrons in a solid are restricted to certain ranges, or bands, of energy (vertical axis). In an insulator or semiconductor, an electron bound to an atom can break free only if it gets enough energy from heat or a passing photon to jump the “band gap”, but in graphene the gap is infinitely small.

Diamond, graphene, and graphite are all network solids.

Suggest, giving a reason, the electron mobility of diamond compared to graphene.

Diamond, graphene, and graphite are all network solids.

Suggest, giving a reason, the electron mobility of diamond compared to graphene.

Determine the limiting reactant showing your working.

Diamond, graphene, and graphite are all network solids.

Suggest, giving a reason, the electron mobility of diamond compared to graphene.

The melting point of diamond at 1 × 10⁶ kPa is 4200 K (in the absence of oxygen).

Suggest, based on molecular structure, why graphene has a higher melting point under these conditions.

The melting point of diamond at 1 × 10⁶ kPa is 4200 K (in the absence of oxygen).

Suggest, based on molecular structure, why graphene has a higher melting point under these conditions.

The melting point of diamond at 1 × 10⁶ kPa is 4200 K (in the absence of oxygen).

Suggest, based on molecular structure, why graphene has a higher melting point under these conditions.

Describe two differences, other than the number of atoms, between the models of ethane and ethene constructed from the kit shown.

Describe two differences, other than the number of atoms, between the models of ethane and ethene constructed from the kit shown.

Describe two differences, other than the number of atoms, between the models of ethane and ethene constructed from the kit shown.

Bromate(V) ions act as oxidizing agents in acidic conditions to form bromide ions.

Deduce the half-equation for this reduction reaction.

The above ball and stick model is a substituted pyridine molecule (made of carbon, hydrogen, nitrogen, bromine and chlorine atoms). All atoms are shown and represented according to their relative atomic size.

Label each ball in the diagram, excluding hydrogens, as a carbon, C, nitrogen, N, bromine, Br, or chlorine, Cl.

Determine the limiting reactant showing your working.

Determine the limiting reactant showing your working.

The above ball and stick model is a substituted pyridine molecule (made of carbon, hydrogen, nitrogen, bromine and chlorine atoms). All atoms are shown and represented according to their relative atomic size.

Label each ball in the diagram, excluding hydrogens, as a carbon, C, nitrogen, N, bromine, Br, or chlorine, Cl.

The above ball and stick model is a substituted pyridine molecule (made of carbon, hydrogen, nitrogen, bromine and chlorine atoms). All atoms are shown and represented according to their relative atomic size.

Label each ball in the diagram, excluding hydrogens, as a carbon, C, nitrogen, N, bromine, Br, or chlorine, Cl.

Pyridine, like benzene, is an aromatic compound.

Outline what is meant by an aromatic compound.

Pyridine, like benzene, is an aromatic compound.

Outline what is meant by an aromatic compound.

Pyridine, like benzene, is an aromatic compound.

Outline what is meant by an aromatic compound.

The mass of copper obtained experimentally was 0.872 g. Calculate the percentage yield of copper.

The mass of copper obtained experimentally was 0.872 g. Calculate the percentage yield of copper.

The mass of copper obtained experimentally was 0.872 g. Calculate the percentage yield of copper.

Bromate(V) ions act as oxidizing agents in acidic conditions to form bromide ions.

Deduce the half-equation for this reduction reaction.

Bromate(V) ions act as oxidizing agents in acidic conditions to form bromide ions.

Deduce the half-equation for this reduction reaction.

Bromate(V) ions oxidize iron(II) ions, Fe²⁺, to iron(III) ions, Fe³⁺.

Deduce the equation for this redox reaction.

Bromate(V) ions oxidize iron(II) ions, Fe²⁺, to iron(III) ions, Fe³⁺.

Deduce the equation for this redox reaction.

Bromate(V) ions oxidize iron(II) ions, Fe²⁺, to iron(III) ions, Fe³⁺.

Deduce the equation for this redox reaction.

The reaction was carried out in a calorimeter. The maximum temperature rise of the solution was 7.5 °C.

Calculate the enthalpy change, ΔH, of the reaction, in kJ, assuming that all the heat released was absorbed by the solution. Use sections 1 and 2 of the data booklet.

The reaction was carried out in a calorimeter. The maximum temperature rise of the solution was 7.5 °C.

Calculate the enthalpy change, ΔH, of the reaction, in kJ, assuming that all the heat released was absorbed by the solution. Use sections 1 and 2 of the data booklet.

The reaction was carried out in a calorimeter. The maximum temperature rise of the solution was 7.5 °C.

Calculate the enthalpy change, ΔH, of the reaction, in kJ, assuming that all the heat released was absorbed by the solution. Use sections 1 and 2 of the data booklet.

Calculate the standard enthalpy change, ΔH^Θ, of step 2 using section 13 of the data booklet.

State another assumption you made in (b)(i).

State the electron configuration of a bromine atom.

Calculate the standard enthalpy change, ΔH^Θ, of step 2 using section 13 of the data booklet.

State another assumption you made in (b)(i).

State another assumption you made in (b)(i).

Calculate the standard enthalpy change, ΔH^Θ, of step 2 using section 13 of the data booklet.

Determine the standard enthalpy change, ΔH^Θ, of step 1.

The only significant uncertainty is in the temperature measurement.

Determine the absolute uncertainty in the calculated value of ΔH if the uncertainty in the temperature rise was ±0.2 °C.

State the electron configuration of a bromine atom.

State the electron configuration of a bromine atom.

Determine the standard enthalpy change, ΔH^Θ, of step 1.

Sketch the orbital diagram of the valence shell of a bromine atom (ground state) on the energy axis provided. Use boxes to represent orbitals and arrows to represent electrons.

The only significant uncertainty is in the temperature measurement.

Determine the absolute uncertainty in the calculated value of ΔH if the uncertainty in the temperature rise was ±0.2 °C.

The only significant uncertainty is in the temperature measurement.

Determine the absolute uncertainty in the calculated value of ΔH if the uncertainty in the temperature rise was ±0.2 °C.

Determine the standard enthalpy change, ΔH^Θ, of step 1.

Determine the empirical formula of the compound, showing your working.

Sketch a graph of the concentration of iron(II) sulfate, FeSO₄, against time as the reaction proceeds.

Sketch the orbital diagram of the valence shell of a bromine atom (ground state) on the energy axis provided. Use boxes to represent orbitals and arrows to represent electrons.

Sketch the orbital diagram of the valence shell of a bromine atom (ground state) on the energy axis provided. Use boxes to represent orbitals and arrows to represent electrons.

Determine the empirical formula of the compound, showing your working.

Sketch a graph of the concentration of iron(II) sulfate, FeSO₄, against time as the reaction proceeds.

Sketch a graph of the concentration of iron(II) sulfate, FeSO₄, against time as the reaction proceeds.

Determine the empirical formula of the compound, showing your working.

Outline how the initial rate of reaction can be determined from the graph in part (c)(i).

Draw two Lewis (electron dot) structures for BrO₃⁻.

Draw two Lewis (electron dot) structures for BrO₃⁻.

Draw two Lewis (electron dot) structures for BrO₃⁻.

Outline how the initial rate of reaction can be determined from the graph in part (c)(i).

Outline how the initial rate of reaction can be determined from the graph in part (c)(i).

The compound could not be oxidized using acidifi ed potassium dichromate(VI).

Deduce the structural formula of the compound.

The compound could not be oxidized using acidifi ed potassium dichromate(VI).

Deduce the structural formula of the compound.

The compound could not be oxidized using acidifi ed potassium dichromate(VI).

Deduce the structural formula of the compound.

Bromate(V) ions act as oxidizing agents in acidic conditions to form bromide ions.

Deduce the half-equation for this reduction reaction.

Draw the structural formula of propan-2-ol.

Bromate(V) ions act as oxidizing agents in acidic conditions to form bromide ions.

Deduce the half-equation for this reduction reaction.

Bromate(V) ions act as oxidizing agents in acidic conditions to form bromide ions.

Deduce the half-equation for this reduction reaction.

Draw two structural isomers of methyloxirane.

Draw two structural isomers of methyloxirane.

Bromate(V) ions oxidize iron(II) ions, Fe²⁺, to iron(III) ions, Fe³⁺.

Deduce the equation for this redox reaction.

Draw the structural formula of propan-2-ol.

Draw the structural formula of propan-2-ol.

Draw two structural isomers of methyloxirane.

Calculate the number of hydrogen atoms in 1.00 g of propan-2-ol.

Bromate(V) ions oxidize iron(II) ions, Fe²⁺, to iron(III) ions, Fe³⁺.

Deduce the equation for this redox reaction.

Bromate(V) ions oxidize iron(II) ions, Fe²⁺, to iron(III) ions, Fe³⁺.

Deduce the equation for this redox reaction.

Calculate the number of hydrogen atoms in 1.00 g of propan-2-ol.

Calculate the number of hydrogen atoms in 1.00 g of propan-2-ol.

Deduce the equation for the relationship between absorbance and concentration.

State a suitable oxidizing agent for the oxidation of propan-2-ol in an acidified aqueous solution.

Deduce the equation for the relationship between absorbance and concentration.

Deduce the equation for the relationship between absorbance and concentration.

Outline how a solution of 0.0100 mol dm⁻³ is obtained from a standard 1.000 mol dm⁻³ copper(II) sulfate solution, including two essential pieces of glassware you would need.

State a suitable oxidizing agent for the oxidation of propan-2-ol in an acidified aqueous solution.

State a suitable oxidizing agent for the oxidation of propan-2-ol in an acidified aqueous solution.

Outline how a solution of 0.0100 mol dm⁻³ is obtained from a standard 1.000 mol dm⁻³ copper(II) sulfate solution, including two essential pieces of glassware you would need.

Outline how a solution of 0.0100 mol dm⁻³ is obtained from a standard 1.000 mol dm⁻³ copper(II) sulfate solution, including two essential pieces of glassware you would need.

The original piece of brass weighed 0.200 g. The absorbance was 0.32.

Calculate, showing your working, the percentage of copper by mass in the brass.

The original piece of brass weighed 0.200 g. The absorbance was 0.32.

Calculate, showing your working, the percentage of copper by mass in the brass.

The original piece of brass weighed 0.200 g. The absorbance was 0.32.

Calculate, showing your working, the percentage of copper by mass in the brass.

Deduce the appropriate number of significant figures for your answer in (d)(i).

Deduce the appropriate number of significant figures for your answer in (d)(i).

Deduce the appropriate number of significant figures for your answer in (d)(i).

Copper(II) ions are reduced to copper(I) iodide by the addition of potassium iodide solution, releasing iodine that can be titrated with sodium thiosulfate solution, Na₂S₂O₃ (aq). Copper(I) iodide is a white solid.

4I⁻ (aq) + 2Cu²⁺ (aq) → 2CuI (s) + I₂ (aq)

I₂ (aq) + 2S₂O₃²⁻ (aq) → 2I⁻ (aq) + S₄O₆²⁻ (aq)

Deduce the overall equation for the two reactions by combining the two equations.

Deduce the product of the oxidation of propan-2-ol with the oxidizing agent in (d)(i).

Copper(II) ions are reduced to copper(I) iodide by the addition of potassium iodide solution, releasing iodine that can be titrated with sodium thiosulfate solution, Na₂S₂O₃ (aq). Copper(I) iodide is a white solid.

4I⁻ (aq) + 2Cu²⁺ (aq) → 2CuI (s) + I₂ (aq)

I₂ (aq) + 2S₂O₃²⁻ (aq) → 2I⁻ (aq) + S₄O₆²⁻ (aq)

Deduce the overall equation for the two reactions by combining the two equations.

Copper(II) ions are reduced to copper(I) iodide by the addition of potassium iodide solution, releasing iodine that can be titrated with sodium thiosulfate solution, Na₂S₂O₃ (aq). Copper(I) iodide is a white solid.

4I⁻ (aq) + 2Cu²⁺ (aq) → 2CuI (s) + I₂ (aq)

I₂ (aq) + 2S₂O₃²⁻ (aq) → 2I⁻ (aq) + S₄O₆²⁻ (aq)

Deduce the overall equation for the two reactions by combining the two equations.

Suggest why the end point of the titration is difficult to determine, even with the addition of starch to turn the remaining free iodine black.

Deduce the product of the oxidation of propan-2-ol with the oxidizing agent in (d)(i).

Deduce the product of the oxidation of propan-2-ol with the oxidizing agent in (d)(i).

Suggest why the end point of the titration is difficult to determine, even with the addition of starch to turn the remaining free iodine black.

Suggest why the end point of the titration is difficult to determine, even with the addition of starch to turn the remaining free iodine black.

Deduce the equation for the relationship between absorbance and concentration.

State the electron configuration of a bromine atom.

Deduce the equation for the relationship between absorbance and concentration.

Deduce the equation for the relationship between absorbance and concentration.

Outline how a solution of 0.0100 mol dm⁻³ is obtained from a standard 1.000 mol dm⁻³ copper(II) sulfate solution, including two essential pieces of glassware you would need.

Outline how a solution of 0.0100 mol dm⁻³ is obtained from a standard 1.000 mol dm⁻³ copper(II) sulfate solution, including two essential pieces of glassware you would need.

State the electron configuration of a bromine atom.

State the electron configuration of a bromine atom.

Outline how a solution of 0.0100 mol dm⁻³ is obtained from a standard 1.000 mol dm⁻³ copper(II) sulfate solution, including two essential pieces of glassware you would need.

The original piece of brass weighed 0.200 g. The absorbance was 0.32.

Calculate, showing your working, the percentage of copper by mass in the brass.

The original piece of brass weighed 0.200 g. The absorbance was 0.32.

Calculate, showing your working, the percentage of copper by mass in the brass.

The original piece of brass weighed 0.200 g. The absorbance was 0.32.

Calculate, showing your working, the percentage of copper by mass in the brass.

Deduce the appropriate number of significant figures for your answer in (e)(i).

0.200 mol sulfur dioxide, 0.300 mol oxygen and 0.500 mol sulfur trioxide were mixed in a 1.00 dm³ flask at 1000 K.

Predict the direction of the reaction showing your working.

Deduce the appropriate number of significant figures for your answer in (e)(i).

0.200 mol sulfur dioxide, 0.300 mol oxygen and 0.500 mol sulfur trioxide were mixed in a 1.00 dm³ flask at 1000 K.

Predict the direction of the reaction showing your working.

0.200 mol sulfur dioxide, 0.300 mol oxygen and 0.500 mol sulfur trioxide were mixed in a 1.00 dm³ flask at 1000 K.

Predict the direction of the reaction showing your working.

Sketch the orbital diagram of the valence shell of a bromine atom (ground state) on the energy axis provided. Use boxes to represent orbitals and arrows to represent electrons.

Deduce the appropriate number of significant figures for your answer in (e)(i).

Titration is another method for analysing the solution obtained from adding brass to nitric acid.

Copper(II) ions are reduced to copper(I) iodide by the addition of potassium iodide solution, releasing iodine that can be titrated with sodium thiosulfate solution, Na₂S₂O₃ (aq). Copper(I) iodide is a white solid.

4I⁻ (aq) + 2Cu²⁺ (aq) → 2CuI (s) + I₂ (aq)

I₂ (aq) + 2S₂O₃²⁻ (aq) → 2I⁻ (aq) + S₄O₆²⁻ (aq)

Suggest why the end point of the titration is difficult to determine, even with the addition of starch to turn the remaining free iodine black.

Titration is another method for analysing the solution obtained from adding brass to nitric acid.

Copper(II) ions are reduced to copper(I) iodide by the addition of potassium iodide solution, releasing iodine that can be titrated with sodium thiosulfate solution, Na₂S₂O₃ (aq). Copper(I) iodide is a white solid.

4I⁻ (aq) + 2Cu²⁺ (aq) → 2CuI (s) + I₂ (aq)

I₂ (aq) + 2S₂O₃²⁻ (aq) → 2I⁻ (aq) + S₄O₆²⁻ (aq)

Suggest why the end point of the titration is difficult to determine, even with the addition of starch to turn the remaining free iodine black.

Titration is another method for analysing the solution obtained from adding brass to nitric acid.

Copper(II) ions are reduced to copper(I) iodide by the addition of potassium iodide solution, releasing iodine that can be titrated with sodium thiosulfate solution, Na₂S₂O₃ (aq). Copper(I) iodide is a white solid.

4I⁻ (aq) + 2Cu²⁺ (aq) → 2CuI (s) + I₂ (aq)

I₂ (aq) + 2S₂O₃²⁻ (aq) → 2I⁻ (aq) + S₄O₆²⁻ (aq)

Suggest why the end point of the titration is difficult to determine, even with the addition of starch to turn the remaining free iodine black.

State the number of ¹H NMR signals for this isomer of xylene and the ratio in which they appear.

Sketch the orbital diagram of the valence shell of a bromine atom (ground state) on the energy axis provided. Use boxes to represent orbitals and arrows to represent electrons.

Sketch the orbital diagram of the valence shell of a bromine atom (ground state) on the energy axis provided. Use boxes to represent orbitals and arrows to represent electrons.

Draw the Lewis (electron dot) structure for BrO₃⁻ that obeys the octet rule.

Draw the Lewis (electron dot) structure for BrO₃⁻ that obeys the octet rule.

Draw the Lewis (electron dot) structure for BrO₃⁻ that obeys the octet rule.

0.200 mol sulfur dioxide, 0.300 mol oxygen and 0.500 mol sulfur trioxide were mixed in a 1.00 dm³ flask at 1000 K.

Predict the direction of the reaction showing your working.

0.200 mol sulfur dioxide, 0.300 mol oxygen and 0.500 mol sulfur trioxide were mixed in a 1.00 dm³ flask at 1000 K.

Predict the direction of the reaction showing your working.

0.200 mol sulfur dioxide, 0.300 mol oxygen and 0.500 mol sulfur trioxide were mixed in a 1.00 dm³ flask at 1000 K.

Predict the direction of the reaction showing your working.

State the equation for the reaction of each substance with water.

State the equation for the reaction of each substance with water.

State the equation for the reaction of each substance with water.

State the equation for the reaction of each substance with water.

State the equation for the reaction of each substance with water.

State the equation for the reaction of each substance with water.

State the number of ¹H NMR signals for this isomer of xylene and the ratio in which they appear.

State the number of ¹H NMR signals for this isomer of xylene and the ratio in which they appear.

A 0.250 mol dm⁻³ aqueous solution of butanoic acid has a concentration of hydrogen ions, [H⁺], of 0.00192 mol dm⁻³. Calculate the concentration of hydroxide ions, [OH⁻], in the solution at 298 K.

Draw the structure of one other isomer of xylene which retains the benzene ring.

In a laboratory experiment solutions of potassium iodide and hydrogen peroxide were mixed and the volume of oxygen generated was recorded. The volume was adjusted to 0 at t = 0.

The data for the first trial is given below.

Plot a graph on the axes below and from it determine the average rate of
formation of oxygen gas in cm³ O₂ (g) s⁻¹.

Average rate of reaction:

Draw the structure of one other isomer of xylene which retains the benzene ring.

A 0.250 mol dm⁻³ aqueous solution of butanoic acid has a concentration of hydrogen ions, [H⁺], of 0.00192 mol dm⁻³. Calculate the concentration of hydroxide ions, [OH⁻], in the solution at 298 K.

A 0.250 mol dm⁻³ aqueous solution of butanoic acid has a concentration of hydrogen ions, [H⁺], of 0.00192 mol dm⁻³. Calculate the concentration of hydroxide ions, [OH⁻], in the solution at 298 K.

Draw the structure of one other isomer of xylene which retains the benzene ring.

Identify the initiation step of the reaction and its conditions.

In a laboratory experiment solutions of potassium iodide and hydrogen peroxide were mixed and the volume of oxygen generated was recorded. The volume was adjusted to 0 at t = 0.

The data for the first trial is given below.

Plot a graph on the axes below and from it determine the average rate of
formation of oxygen gas in cm³ O₂ (g) s⁻¹.

Average rate of reaction:

In a laboratory experiment solutions of potassium iodide and hydrogen peroxide were mixed and the volume of oxygen generated was recorded. The volume was adjusted to 0 at t = 0.

The data for the first trial is given below.

Plot a graph on the axes below and from it determine the average rate of
formation of oxygen gas in cm³ O₂ (g) s⁻¹.

Average rate of reaction:

Identify the initiation step of the reaction and its conditions.

Sketch the pH curve for the titration of 25.0 cm³ of ethylamine aqueous solution with 50.0 cm³ of butanoic acid aqueous solution of equal concentration. No calculations are required.

Identify the initiation step of the reaction and its conditions.

1,4-dimethylbenzene reacts as a substituted alkane. Draw the structures of the two products of the overall reaction when one molecule of bromine reacts with one molecule of 1,4-dimethylbenzene.

Sketch the pH curve for the titration of 25.0 cm³ of ethylamine aqueous solution with 50.0 cm³ of butanoic acid aqueous solution of equal concentration. No calculations are required.

Sketch the pH curve for the titration of 25.0 cm³ of ethylamine aqueous solution with 50.0 cm³ of butanoic acid aqueous solution of equal concentration. No calculations are required.

Additional experiments were carried out at an elevated temperature. On the axes below, sketch Maxwell–Boltzmann energy distribution curves at two temperatures T₁ and T₂, where T₂ > T₁.

1,4-dimethylbenzene reacts as a substituted alkane. Draw the structures of the two products of the overall reaction when one molecule of bromine reacts with one molecule of 1,4-dimethylbenzene.

Additional experiments were carried out at an elevated temperature. On the axes below, sketch Maxwell–Boltzmann energy distribution curves at two temperatures T₁ and T₂, where T₂ > T₁.

Additional experiments were carried out at an elevated temperature. On the axes below, sketch Maxwell–Boltzmann energy distribution curves at two temperatures T₁ and T₂, where T₂ > T₁.

1,4-dimethylbenzene reacts as a substituted alkane. Draw the structures of the two products of the overall reaction when one molecule of bromine reacts with one molecule of 1,4-dimethylbenzene.

Outline one piece of physical evidence for the structure of the benzene ring.

Apart from a greater frequency of collisions, explain, by annotating your graphs in (b)(iii), why an increased temperature causes the rate of reaction to increase.

Outline one piece of physical evidence for the structure of the benzene ring.

Apart from a greater frequency of collisions, explain, by annotating your graphs in (b)(iii), why an increased temperature causes the rate of reaction to increase.

Apart from a greater frequency of collisions, explain, by annotating your graphs in (b)(iii), why an increased temperature causes the rate of reaction to increase.

MnO₂ is another possible catalyst for the reaction. State the IUPAC name for MnO₂.

Outline one piece of physical evidence for the structure of the benzene ring.

Draw the structure of the conjugate base of benzoic acid showing all the atoms and all the bonds.

MnO₂ is another possible catalyst for the reaction. State the IUPAC name for MnO₂.

MnO₂ is another possible catalyst for the reaction. State the IUPAC name for MnO₂.

Draw the structure of the conjugate base of benzoic acid showing all the atoms and all the bonds.

Comment on why peracetic acid, CH3COOOH, is always sold in solution with ethanoic acid and hydrogen peroxide.

H₂O₂ (aq) + CH₃COOH (aq) ⇌ CH₃COOOH (aq) + H₂O (l)

Draw the structure of the conjugate base of benzoic acid showing all the atoms and all the bonds.

The pH of an aqueous solution of benzoic acid at 298 K is 2.95. Determine the concentration of hydroxide ions in the solution, using section 2 of the data booklet.

The pH of an aqueous solution of benzoic acid at 298 K is 2.95. Determine the concentration of hydroxide ions in the solution, using section 2 of the data booklet.

Comment on why peracetic acid, CH3COOOH, is always sold in solution with ethanoic acid and hydrogen peroxide.

H₂O₂ (aq) + CH₃COOH (aq) ⇌ CH₃COOOH (aq) + H₂O (l)

Comment on why peracetic acid, CH3COOOH, is always sold in solution with ethanoic acid and hydrogen peroxide.

H₂O₂ (aq) + CH₃COOH (aq) ⇌ CH₃COOOH (aq) + H₂O (l)

Sodium percarbonate, 2Na₂CO₃•3H₂O₂, is an adduct of sodium carbonate and hydrogen peroxide and is used as a cleaning agent.

M_r (2Na₂CO₃•3H₂O₂) = 314.04

Calculate the percentage by mass of hydrogen peroxide in sodium percarbonate, giving your answer to two decimal places.

Deduce the full electron configuration of Fe²⁺.

Deduce the full electron configuration of Fe²⁺.

Deduce the full electron configuration of Fe²⁺.

The pH of an aqueous solution of benzoic acid at 298 K is 2.95. Determine the concentration of hydroxide ions in the solution, using section 2 of the data booklet.

Formulate the equation for the complete combustion of benzoic acid in oxygen using only integer coefficients.

Formulate the equation for the complete combustion of benzoic acid in oxygen using only integer coefficients.

State the nuclear symbol notation, ${}_{\text{Z}}^{\text{A}}\text{X}$, for iron-54.

Sodium percarbonate, 2Na₂CO₃•3H₂O₂, is an adduct of sodium carbonate and hydrogen peroxide and is used as a cleaning agent.

M_r (2Na₂CO₃•3H₂O₂) = 314.04

Calculate the percentage by mass of hydrogen peroxide in sodium percarbonate, giving your answer to two decimal places.

Sodium percarbonate, 2Na₂CO₃•3H₂O₂, is an adduct of sodium carbonate and hydrogen peroxide and is used as a cleaning agent.

M_r (2Na₂CO₃•3H₂O₂) = 314.04

Calculate the percentage by mass of hydrogen peroxide in sodium percarbonate, giving your answer to two decimal places.

Outline why ethanoic acid is classified as a weak acid.

Formulate the equation for the complete combustion of benzoic acid in oxygen using only integer coefficients.

The combustion reaction in (f)(ii) can also be classed as redox. Identify the atom that is oxidized and the atom that is reduced.

Outline why ethanoic acid is classified as a weak acid.

Outline why ethanoic acid is classified as a weak acid.

State the nuclear symbol notation, ${}_{\text{Z}}^{\text{A}}\text{X}$, for iron-54.

State the nuclear symbol notation, ${}_{\text{Z}}^{\text{A}}\text{X}$, for iron-54.

The combustion reaction in (f)(ii) can also be classed as redox. Identify the atom that is oxidized and the atom that is reduced.

The combustion reaction in (f)(ii) can also be classed as redox. Identify the atom that is oxidized and the atom that is reduced.

Suggest how benzoic acid, M_r = 122.13, forms an apparent dimer, M_r = 244.26, when dissolved in a non-polar solvent such as hexane.

Mass spectrometry analysis of a sample of iron gave the following results:

Calculate the relative atomic mass, A_r, of this sample of iron to two decimal places.

Mass spectrometry analysis of a sample of iron gave the following results:

Calculate the relative atomic mass, A_r, of this sample of iron to two decimal places.

Mass spectrometry analysis of a sample of iron gave the following results:

Calculate the relative atomic mass, A_r, of this sample of iron to two decimal places.

A solution of bleach can be made by reacting chlorine gas with a sodium hydroxide solution.

Cl₂ (g) + 2NaOH (aq) ⇌ NaOCl (aq) + NaCl (aq) + H₂O (l)

Suggest, with reference to Le Châtelier’s principle, why it is dangerous to mix vinegar and bleach together as cleaners.

A solution of bleach can be made by reacting chlorine gas with a sodium hydroxide solution.

Cl₂ (g) + 2NaOH (aq) ⇌ NaOCl (aq) + NaCl (aq) + H₂O (l)

Suggest, with reference to Le Châtelier’s principle, why it is dangerous to mix vinegar and bleach together as cleaners.

A solution of bleach can be made by reacting chlorine gas with a sodium hydroxide solution.

Cl₂ (g) + 2NaOH (aq) ⇌ NaOCl (aq) + NaCl (aq) + H₂O (l)

Suggest, with reference to Le Châtelier’s principle, why it is dangerous to mix vinegar and bleach together as cleaners.

Suggest how benzoic acid, M_r = 122.13, forms an apparent dimer, M_r = 244.26, when dissolved in a non-polar solvent such as hexane.

Draw a Lewis (electron dot) structure of chloramine.

Suggest how benzoic acid, M_r = 122.13, forms an apparent dimer, M_r = 244.26, when dissolved in a non-polar solvent such as hexane.

Outline why the alkali metals (group 1) have similar chemical properties.

Outline why the alkali metals (group 1) have similar chemical properties.

Draw a Lewis (electron dot) structure of chloramine.

Draw a Lewis (electron dot) structure of chloramine.

Deduce the molecular geometry of chloramine and estimate its H–N–H bond angle.

Molecular geometry:

H–N–H bond angle:

Deduce the molecular geometry of chloramine and estimate its H–N–H bond angle.

Molecular geometry:

H–N–H bond angle:

Deduce the molecular geometry of chloramine and estimate its H–N–H bond angle.

Molecular geometry:

H–N–H bond angle:

State the type of bond formed when chloramine is protonated.

State the type of bond formed when chloramine is protonated.

State the type of bond formed when chloramine is protonated.

An iron nail and a copper nail are inserted into a lemon.

Explain why a potential is detected when the nails are connected through a voltmeter.

An iron nail and a copper nail are inserted into a lemon.

Explain why a potential is detected when the nails are connected through a voltmeter.

An iron nail and a copper nail are inserted into a lemon.

Explain why a potential is detected when the nails are connected through a voltmeter.

Write an equation for the complete combustion of ethyne.

Write an equation for the complete combustion of ethyne.

Write an equation for the complete combustion of ethyne.

Deduce the Lewis (electron dot) structure of ethyne.

Outline why the alkali metals (group 1) have similar chemical properties.

Describe the structure and bonding in solid sodium oxide.

Deduce the Lewis (electron dot) structure of ethyne.

Deduce the Lewis (electron dot) structure of ethyne.

Compare, giving a reason, the length of the bond between the carbon atoms in ethyne with that in ethane, C₂H₆.

Compare, giving a reason, the length of the bond between the carbon atoms in ethyne with that in ethane, C₂H₆.

Compare, giving a reason, the length of the bond between the carbon atoms in ethyne with that in ethane, C₂H₆.

Outline why ozone in the stratosphere is important.

Outline why ozone in the stratosphere is important.

Outline why ozone in the stratosphere is important.

Describe the structure and bonding in solid sodium oxide.

State one analytical technique that could be used to determine the ratio of ¹⁴N : ¹⁵N.

Identify the type of interaction that must be overcome when liquid ethyne vaporizes.

Identify the type of interaction that must be overcome when liquid ethyne vaporizes.

Identify the type of interaction that must be overcome when liquid ethyne vaporizes.

Describe the structure and bonding in solid sodium oxide.

Write equations for the separate reactions of solid sodium oxide and solid phosphorus(V) oxide with excess water and differentiate between the solutions formed.

Sodium oxide, Na₂O:

Phosphorus(V) oxide, P₄O₁₀:

Differentiation:

State the name of product B, applying IUPAC rules.

State the name of product B, applying IUPAC rules.

State the name of product B, applying IUPAC rules.

State one analytical technique that could be used to determine the ratio of ¹⁴N : ¹⁵N.

State one analytical technique that could be used to determine the ratio of ¹⁴N : ¹⁵N.

A sample of gas was enriched to contain 2 % by mass of ¹⁵N with the remainder being ¹⁴N.

Calculate the relative molecular mass of the resulting N₂O.

Write equations for the separate reactions of solid sodium oxide and solid phosphorus(V) oxide with excess water and differentiate between the solutions formed.