Topic 5: Energetics/thermochemistry

A student obtained the following data to calculate $q$, using $q=mc\mathrm{\Delta }T$.

$m=20.2 \mathrm{g}\pm 0.2 \mathrm{g}$

$∆T=10°\mathrm{C}\pm 1°\mathrm{C}$

$c=4.18 \mathrm{J} {\mathrm{g}}^{-1} {\mathrm{K}}^{-1}$

What is the percentage uncertainty in the calculated value of $q$?

A.  $0.2$

B.  $1.2$

C.  $11$

D.  $14$

Which equation shows the enthalpy of formation, $∆H_{\mathrm{f}}$, of ethanol?

A.  $2\mathrm{C} \left(\mathrm{s}\right)+3{\mathrm{H}}_2 \left(\mathrm{g}\right)+\frac{1}{2}{\mathrm{O}}_2 \left(\mathrm{g}\right)\to {\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH} \left(\mathrm{g}\right)$

B.  $4\mathrm{C} \left(\mathrm{s}\right)+6{\mathrm{H}}_2 \left(\mathrm{g}\right)+{\mathrm{O}}_2 \left(\mathrm{g}\right)\to 2{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH} \left(\mathrm{g}\right)$

C.  $2\mathrm{C} \left(\mathrm{s}\right)+3{\mathrm{H}}_2 \left(\mathrm{g}\right)+\frac{1}{2}{\mathrm{O}}_2 \left(\mathrm{g}\right)\to {\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH} \left(\mathrm{l}\right)$

D.  $4\mathrm{C} \left(\mathrm{s}\right)+6{\mathrm{H}}_2 \left(\mathrm{g}\right)+{\mathrm{O}}_2 \left(\mathrm{g}\right)\to 2{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH} \left(\mathrm{l}\right)$

Which statements about bond strength and activation energy are correct for this reaction?

${\mathrm{CH}}_4 \left(\mathrm{g}\right)+2{\mathrm{O}}_2 \left(\mathrm{g}\right)\to {\mathrm{CO}}_2 \left(\mathrm{g}\right)+2{\mathrm{H}}_2\mathrm{O} \left(\mathrm{l}\right)$      $∆H^{⦵}=-891 \mathrm{kJ}$

Which statements about bond strength and activation energy are correct for this reaction?

${\mathrm{CH}}_4 \left(\mathrm{g}\right)+2{\mathrm{O}}_2 \left(\mathrm{g}\right)\to {\mathrm{CO}}_2 \left(\mathrm{g}\right)+2{\mathrm{H}}_2\mathrm{O} \left(\mathrm{l}\right)$      $∆H^{⦵}=-891 \mathrm{kJ}$

A student obtained the following data to calculate $q$, using $q=mc\mathrm{\Delta }T$.

$m=20.2 \mathrm{g}\pm 0.2 \mathrm{g}$

$∆T=10°\mathrm{C}\pm 1°\mathrm{C}$

$c=4.18 \mathrm{J} {\mathrm{g}}^{-1} {\mathrm{K}}^{-1}$

What is the percentage uncertainty in the calculated value of $q$?

A.  $0.2$

B.  $1.2$

C.  $11$

D.  $14$

Determine the standard enthalpy change, $∆H^{⦵}$, for this reaction, using section 11 of the data booklet.

Which equation shows the enthalpy of formation, $∆H_{\mathrm{f}}$, of ethanol?

A.  $2\mathrm{C} \left(\mathrm{s}\right)+3{\mathrm{H}}_2 \left(\mathrm{g}\right)+\frac{1}{2}{\mathrm{O}}_2 \left(\mathrm{g}\right)\to {\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH} \left(\mathrm{g}\right)$

B.  $4\mathrm{C} \left(\mathrm{s}\right)+6{\mathrm{H}}_2 \left(\mathrm{g}\right)+{\mathrm{O}}_2 \left(\mathrm{g}\right)\to 2{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH} \left(\mathrm{g}\right)$

C.  $2\mathrm{C} \left(\mathrm{s}\right)+3{\mathrm{H}}_2 \left(\mathrm{g}\right)+\frac{1}{2}{\mathrm{O}}_2 \left(\mathrm{g}\right)\to {\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH} \left(\mathrm{l}\right)$

D.  $4\mathrm{C} \left(\mathrm{s}\right)+6{\mathrm{H}}_2 \left(\mathrm{g}\right)+{\mathrm{O}}_2 \left(\mathrm{g}\right)\to 2{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH} \left(\mathrm{l}\right)$

Which combination will give you the enthalpy change for the hydrogenation of ethene to ethane, $∆H_3$?

A.  $-∆H_2+∆H_1-∆H_4$

B.  $∆H_2\mathit{-}∆H_1+∆H_4$

C.  $∆H_2+∆H_1-∆H_4$

D.  $-∆H_2\mathit{-}∆H_1+∆H_4$

Calculate the standard enthalpy change, $∆H^{⦵}$, for this reaction using section 12 of the data booklet.

Determine the standard enthalpy change, $∆H^{⦵}$, for this reaction, using section 11 of the data booklet.

Determine the standard enthalpy change, $∆H^{⦵}$, for this reaction, using section 11 of the data booklet.

Calculate the standard enthalpy change, $∆H^{⦵}$, for this reaction using section 12 of the data booklet.

Calculate the standard enthalpy change, $∆H^{⦵}$, for this reaction using section 12 of the data booklet.

Which combination will give you the enthalpy change for the hydrogenation of ethene to ethane, $∆H_3$?

A.  $-∆H_2+∆H_1-∆H_4$

B.  $∆H_2\mathit{-}∆H_1+∆H_4$

C.  $∆H_2+∆H_1-∆H_4$

D.  $-∆H_2\mathit{-}∆H_1+∆H_4$

What is the $\mathrm{H}-\mathrm{H}$ bond enthalpy, in $\mathrm{kJ} {\mathrm{mol}}^{-1}$, in the ${\mathrm{H}}_2$ molecule?

$2{\mathrm{H}}_2\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\to 2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$

$∆H_{\mathrm{f}}\left({\mathrm{H}}_2\mathrm{O}\right)=x \mathrm{kJ} {\mathrm{mol}}^{-1}$

A.  $x-y+4z$

B.  $\frac{1}{2}\left(x-y+4z\right)$

C.  $x-y+2z$

D.  $\frac{1}{2}\left(x-y+2z\right)$

Calculate the standard enthalpy change, $∆H^{⦵}$, for this reaction using section 12 of the data booklet.

Determine the standard enthalpy change, $∆H^{⦵}$, for this reaction, using section 11 of the data booklet.

What is the $\mathrm{H}-\mathrm{H}$ bond enthalpy, in $\mathrm{kJ} {\mathrm{mol}}^{-1}$, in the ${\mathrm{H}}_2$ molecule?

$2{\mathrm{H}}_2\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\to 2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$

$∆H_{\mathrm{f}}\left({\mathrm{H}}_2\mathrm{O}\right)=x \mathrm{kJ} {\mathrm{mol}}^{-1}$

A.  $x-y+4z$

B.  $\frac{1}{2}\left(x-y+4z\right)$

C.  $x-y+2z$

D.  $\frac{1}{2}\left(x-y+2z\right)$

Calculate the standard enthalpy change, $∆H^{⦵}$, for this reaction using section 12 of the data booklet.

Calculate the standard enthalpy change, $∆H^{⦵}$, for this reaction using section 12 of the data booklet.

Determine the standard enthalpy change, $∆H^{⦵}$, for this reaction, using section 11 of the data booklet.

Determine the standard enthalpy change, $∆H^{⦵}$, for this reaction, using section 11 of the data booklet.

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.

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.

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

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.

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 standard enthalpy change for this reaction using the following data.

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)

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]

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

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

2C (graphite) + O₂(g) → 2CO (g)

A.  −394 − 283

B.  2(−394) + 2(−283)

C.  −394 + 283

D.  2(−394) + 2(283)

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]

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

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.

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

2C (graphite) + O₂(g) → 2CO (g)

A.  −394 − 283

B.  2(−394) + 2(−283)

C.  −394 + 283

D.  2(−394) + 2(283)

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.

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.

What is the enthalpy change, in J, when 5 g of water is heated from 10°C to 18°C?

Specific heat capacity of water: 4.18 kJ kg⁻¹ K⁻¹

A.  5 × 4.18 × 8

B.  5 × 10⁻³ × 4.18 × 8

C.  5 × 4.18 × (273 + 8)

D.  5 × 10⁻³ × 4.18 × (273 + 8)

What is the enthalpy change, in J, when 5 g of water is heated from 10°C to 18°C?

Specific heat capacity of water: 4.18 kJ kg⁻¹ K⁻¹

A.  5 × 4.18 × 8

B.  5 × 10⁻³ × 4.18 × 8

C.  5 × 4.18 × (273 + 8)

D.  5 × 10⁻³ × 4.18 × (273 + 8)

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.

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

What is the heat change, in kJ, when 100.0 g of aluminium is heated from 19.0 °C to 32.0 °C?

Specific heat capacity of aluminium: 0.90 J g⁻¹K⁻¹

A.  $0.90\times 100.0\times 13.0$

B.  $0.90\times 100.0\times 286$

C.  $\frac{0.90\times 100.0\times 13.0}{1000}$

D.  $\frac{0.90\times 100.0\times 286}{1000}$

What is the heat change, in kJ, when 100.0 g of aluminium is heated from 19.0 °C to 32.0 °C?

Specific heat capacity of aluminium: 0.90 J g⁻¹K⁻¹

A.  $0.90\times 100.0\times 13.0$

B.  $0.90\times 100.0\times 286$

C.  $\frac{0.90\times 100.0\times 13.0}{1000}$

D.  $\frac{0.90\times 100.0\times 286}{1000}$

Iron has a relatively small specific heat capacity; the temperature of a 50 g sample rises by 44.4°C when it absorbs 1 kJ of heat energy.

Determine the specific heat capacity of iron, in J g⁻¹K⁻¹. Use section 1 of the data booklet.

Determine the enthalpy change, ΔH, in kJ. Use section 11 of the data booklet.

Bond enthalpy of CO = 1077 kJ mol⁻¹.

Iron has a relatively small specific heat capacity; the temperature of a 50 g sample rises by 44.4°C when it absorbs 1 kJ of heat energy.

Determine the specific heat capacity of iron, in J g⁻¹K⁻¹. Use section 1 of the data booklet.

Iron has a relatively small specific heat capacity; the temperature of a 50 g sample rises by 44.4°C when it absorbs 1 kJ of heat energy.

Determine the specific heat capacity of iron, in J g⁻¹K⁻¹. Use section 1 of the data booklet.

Iron has a relatively small specific heat capacity; the temperature of a 50 g sample rises by 44.4°C when it absorbs 1 kJ of heat energy.

Determine the specific heat capacity of iron, in J g⁻¹K⁻¹. Use section 1 of the data booklet.

Iron has a relatively small specific heat capacity; the temperature of a 50 g sample rises by 44.4°C when it absorbs 1 kJ of heat energy.

Determine the specific heat capacity of iron, in J g⁻¹K⁻¹. Use section 1 of the data booklet.

Iron has a relatively small specific heat capacity; the temperature of a 50 g sample rises by 44.4°C when it absorbs 1 kJ of heat energy.

Determine the specific heat capacity of iron, in J g⁻¹K⁻¹. Use section 1 of the data booklet.

Determine the enthalpy change, ΔH, in kJ. Use section 11 of the data booklet.

Bond enthalpy of CO = 1077 kJ mol⁻¹.

Determine the enthalpy change, ΔH, in kJ. Use section 11 of the data booklet.

Bond enthalpy of CO = 1077 kJ mol⁻¹.

Explain, using equations, how the presence of ${\text{CCl}}_{\text{2}}{\text{F}}_{\text{2}}$ results in a chain reaction that decreases the concentration of ozone in the stratosphere.

State one reason why you would expect the value of ΔH calculated from the $∆H_f^{\mathrm{⦵}}$ values, given in section 12 of data booklet, to differ from your answer to (d)(i).

Thermodynamic data for the decomposition of calcium carbonate is given.

Calculate the enthalpy change of reaction, ΔH, in kJ, for the decomposition of calcium carbonate.

State one reason why you would expect the value of ΔH calculated from the $∆H_f^{\mathrm{⦵}}$ values, given in section 12 of data booklet, to differ from your answer to (d)(i).

State one reason why you would expect the value of ΔH calculated from the $∆H_f^{\mathrm{⦵}}$ values, given in section 12 of data booklet, to differ from your answer to (d)(i).

Explain, using equations, how the presence of ${\text{CCl}}_{\text{2}}{\text{F}}_{\text{2}}$ results in a chain reaction that decreases the concentration of ozone in the stratosphere.

Explain, using equations, how the presence of ${\text{CCl}}_{\text{2}}{\text{F}}_{\text{2}}$ results in a chain reaction that decreases the concentration of ozone in the stratosphere.

Determine the change in enthalpy, ΔH, for the combustion of but-2-ene, using section 11 of the data booklet. 

CH₃CH=CHCH₃(g) + 6O₂ (g) → 4CO₂(g) + 4H₂O (g)

Thermodynamic data for the decomposition of calcium carbonate is given.

Calculate the enthalpy change of reaction, ΔH, in kJ, for the decomposition of calcium carbonate.

Determine the change in enthalpy, ΔH, for the combustion of but-2-ene, using section 11 of the data booklet. 

CH₃CH=CHCH₃(g) + 6O₂ (g) → 4CO₂(g) + 4H₂O (g)

Determine the change in enthalpy, ΔH, for the combustion of but-2-ene, using section 11 of the data booklet. 

CH₃CH=CHCH₃(g) + 6O₂ (g) → 4CO₂(g) + 4H₂O (g)

Determine the change in enthalpy, ΔH, for the combustion of but-2-ene, using section 11 of the data booklet. 

CH₃CH=CHCH₃(g) + 6O₂ (g) → 4CO₂(g) + 4H₂O (g)

Determine the change in enthalpy, ΔH, for the combustion of but-2-ene, using section 11 of the data booklet. 

CH₃CH=CHCH₃(g) + 6O₂ (g) → 4CO₂(g) + 4H₂O (g)

Determine the change in enthalpy, ΔH, for the combustion of but-2-ene, using section 11 of the data booklet. 

CH₃CH=CHCH₃(g) + 6O₂ (g) → 4CO₂(g) + 4H₂O (g)

Thermodynamic data for the decomposition of calcium carbonate is given.

Calculate the enthalpy change of reaction, ΔH, in kJ, for the decomposition of calcium carbonate.

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

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 (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).

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).

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).

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).

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)]

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

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)]

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

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

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

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

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.

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.

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

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.

Calculate the standard enthalpy change (ΔH^⦵) for the forward reaction in kJ mol⁻¹.

ΔH^⦵_f PCl₃(g) = −306.4 kJ mol⁻¹

ΔH^⦵_f PCl₅(g) = −398.9 kJ mol⁻¹

Which combustion reaction releases the least energy per mole of C₃H₈?

Approximate bond enthalpy / kJ mol⁻¹
O=O    500
C=O    800
 C≡O   1000

A.  C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O (g)

B.  C₃H₈(g) + $\frac{9}{2}$O₂(g) → 2CO₂(g) + CO (g) + 4H₂O (g)

C.  C₃H₈(g) + 4O₂(g) → CO₂(g) + 2CO (g) + 4H₂O (g)

D.  C₃H₈(g) + $\frac{7}{2}$O₂(g) → 3CO (g) + 4H₂O (g)

Chemistry: Atoms First 2e, https://openstax.org/books/chemistry-atoms-first-2e/pages/9-4-strengths-of-ionic-andcovalent-bonds © 1999–2021, Rice University. Except where otherwise noted, textbooks on this site are licensed under a Creative Commons Attribution 4.0 International License.
(CC BY 4.0) https://creativecommons.org/licenses/ by/4.0/.

Which combustion reaction releases the least energy per mole of C₃H₈?

Approximate bond enthalpy / kJ mol⁻¹
O=O    500
C=O    800
 C≡O   1000

A.  C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O (g)

B.  C₃H₈(g) + $\frac{9}{2}$O₂(g) → 2CO₂(g) + CO (g) + 4H₂O (g)

C.  C₃H₈(g) + 4O₂(g) → CO₂(g) + 2CO (g) + 4H₂O (g)

D.  C₃H₈(g) + $\frac{7}{2}$O₂(g) → 3CO (g) + 4H₂O (g)

Chemistry: Atoms First 2e, https://openstax.org/books/chemistry-atoms-first-2e/pages/9-4-strengths-of-ionic-andcovalent-bonds © 1999–2021, Rice University. Except where otherwise noted, textbooks on this site are licensed under a Creative Commons Attribution 4.0 International License.
(CC BY 4.0) https://creativecommons.org/licenses/ by/4.0/.

Calculate the standard enthalpy change (ΔH^⦵) for the forward reaction in kJ mol⁻¹.

ΔH^⦵_f PCl₃(g) = −306.4 kJ mol⁻¹

ΔH^⦵_f PCl₅(g) = −398.9 kJ mol⁻¹

Which equation represents the standard enthalpy of formation of lithium oxide?

A.  4Li (s) + O₂(g) → 2Li₂O (s)

B.  2Li (s) + $\frac{1}{2}$O₂(g) → Li₂O (s)

C.  Li (s) + $\frac{1}{4}$O₂(g) → $\frac{1}{2}$Li₂O (s)

D.  Li (g) + $\frac{1}{4}$O₂(g) → $\frac{1}{2}$Li₂O (g)

Which equation represents the standard enthalpy of formation of lithium oxide?

A.  4Li (s) + O₂(g) → 2Li₂O (s)

B.  2Li (s) + $\frac{1}{2}$O₂(g) → Li₂O (s)

C.  Li (s) + $\frac{1}{4}$O₂(g) → $\frac{1}{2}$Li₂O (s)

D.  Li (g) + $\frac{1}{4}$O₂(g) → $\frac{1}{2}$Li₂O (g)

Calculate the standard enthalpy change (ΔH^⦵) for the forward reaction in kJ mol⁻¹.

ΔH^⦵_f PCl₃(g) = −306.4 kJ mol⁻¹

ΔH^⦵_f PCl₅(g) = −398.9 kJ mol⁻¹

Calculate the standard enthalpy change (ΔH^⦵) for the forward reaction in kJ mol⁻¹.

ΔH^⦵_f PCl₃(g) = −306.4 kJ mol⁻¹

ΔH^⦵_f PCl₅(g) = −398.9 kJ mol⁻¹

Calculate the standard enthalpy change (ΔH^⦵) for the forward reaction in kJ mol⁻¹.

ΔH^⦵_f PCl₃(g) = −306.4 kJ mol⁻¹

ΔH^⦵_f PCl₅(g) = −398.9 kJ mol⁻¹

Calculate the standard enthalpy change (ΔH^⦵) for the forward reaction in kJ mol⁻¹.

ΔH^⦵_f PCl₃(g) = −306.4 kJ mol⁻¹

ΔH^⦵_f PCl₅(g) = −398.9 kJ mol⁻¹

The energy from burning 0.250 g of ethanol causes the temperature of 150 cm³ of water to rise by 10.5 °C. What is the enthalpy of combustion of ethanol, in kJ mol^–1?

Specific heat capacity of water: 4.18 J g^–1K^–1.

A.  $\frac{150\times 4.18\times 10.5}{{\displaystyle \frac{0.250}{46.08}}}$

B.  $\frac{150\times 4.18\times 10.5}{{\displaystyle \frac{0.250}{46.08}}\times 1000}$

C.  $\frac{150\times 4.18\times \left(273+10.5\right)}{{\displaystyle \frac{0.250}{46.08}}}$

D.  $\frac{150\times 4.18\times \left(273+10.5\right)}{{\displaystyle \frac{0.250}{46.08}}\times 1000}$

Determine the molar enthalpy of combustion of an alkane if 8.75 × 10⁻⁴ moles are burned, raising the temperature of 20.0 g of water by 57.3 °C.

Determine the molar enthalpy of combustion of an alkane if 8.75 × 10⁻⁴ moles are burned, raising the temperature of 20.0 g of water by 57.3 °C.

Determine the molar enthalpy of combustion of an alkane if 8.75 × 10⁻⁴ moles are burned, raising the temperature of 20.0 g of water by 57.3 °C.

The energy from burning 0.250 g of ethanol causes the temperature of 150 cm³ of water to rise by 10.5 °C. What is the enthalpy of combustion of ethanol, in kJ mol^–1?

Specific heat capacity of water: 4.18 J g^–1K^–1.

A.  $\frac{150\times 4.18\times 10.5}{{\displaystyle \frac{0.250}{46.08}}}$

B.  $\frac{150\times 4.18\times 10.5}{{\displaystyle \frac{0.250}{46.08}}\times 1000}$

C.  $\frac{150\times 4.18\times \left(273+10.5\right)}{{\displaystyle \frac{0.250}{46.08}}}$

D.  $\frac{150\times 4.18\times \left(273+10.5\right)}{{\displaystyle \frac{0.250}{46.08}}\times 1000}$

State another assumption you made in (b)(i).

State another assumption you made in (b)(i).

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.

State another assumption you made in (b)(i).

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.

State another assumption you made in (b)(i).

State another assumption you made in (b)(i).

State another assumption you made in (b)(i).

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.

Determine the standard enthalpy change, ΔH^Θ, of step 1.

Calculate the standard enthalpy change, ΔH^Θ, of step 2 using section 13 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.

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.

Determine the standard enthalpy change, ΔH^Θ, of step 1.

Which combination of ΔH₁, ΔH₂, and ΔH₃ would give the enthalpy of the reaction?

CS₂(l) + 3O₂(g) → CO₂(g) + 2SO₂(g)

ΔH₁  C (s) + O₂(g) → CO₂(g)
ΔH₂  S (s) + O₂(g) → SO₂(g)
ΔH₃  C (s) + 2S (s) → CS₂(l)

A.  ΔH = ΔH₁ + ΔH₂ + ΔH₃

B.  ΔH = ΔH₁ + ΔH₂ − ΔH₃

C.  ΔH = ΔH₁ + 2(ΔH₂) + ΔH₃

D.  ΔH = ΔH₁ + 2(ΔH₂) − ΔH₃

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.

Which combination of ΔH₁, ΔH₂, and ΔH₃ would give the enthalpy of the reaction?

CS₂(l) + 3O₂(g) → CO₂(g) + 2SO₂(g)

ΔH₁  C (s) + O₂(g) → CO₂(g)
ΔH₂  S (s) + O₂(g) → SO₂(g)
ΔH₃  C (s) + 2S (s) → CS₂(l)

A.  ΔH = ΔH₁ + ΔH₂ + ΔH₃

B.  ΔH = ΔH₁ + ΔH₂ − ΔH₃

C.  ΔH = ΔH₁ + 2(ΔH₂) + ΔH₃

D.  ΔH = ΔH₁ + 2(ΔH₂) − ΔH₃

Calculate the enthalpy change, ΔH^⦵, for the Haber–Bosch process, in kJ, using the following data.

$∆H_{ \mathrm{f}}^{⦵}\left({\mathrm{NH}}_3\right)=-46.2 \mathrm{kJ} {\mathrm{mol}}^{-1}$.

Which equation represents the bond enthalpy for H–Br in hydrogen bromide?

A.  HBr (g) → H⁺ (g) + Br⁻ (g)

B.  HBr (g) → H (g) + Br (g)

C.  HBr (g) → $\frac{1}{2}$H₂ (g) + $\frac{1}{2}$Br₂ (l)

D.  HBr (g) → $\frac{1}{2}$H₂ (g) + $\frac{1}{2}$Br₂ (g)

Which equation represents the bond enthalpy for H–Br in hydrogen bromide?

A.  HBr (g) → H⁺ (g) + Br⁻ (g)

B.  HBr (g) → H (g) + Br (g)

C.  HBr (g) → $\frac{1}{2}$H₂ (g) + $\frac{1}{2}$Br₂ (l)

D.  HBr (g) → $\frac{1}{2}$H₂ (g) + $\frac{1}{2}$Br₂ (g)

Outline why the value obtained in (b)(i) might differ from a value calculated using ΔH_f data.

Determine the enthalpy change, ΔH, for the Haber–Bosch process, in kJ. Use Section 11 of the data booklet.

Calculate the enthalpy change, ΔH^⦵, for the Haber–Bosch process, in kJ, using the following data.

$∆H_{ \mathrm{f}}^{⦵}\left({\mathrm{NH}}_3\right)=-46.2 \mathrm{kJ} {\mathrm{mol}}^{-1}$.

Determine the enthalpy change, ΔH, for the Haber–Bosch process, in kJ. Use Section 11 of the data booklet.

Determine the enthalpy change, ΔH, for the Haber–Bosch process, in kJ. Use Section 11 of the data booklet.

Draw and label an enthalpy level diagram for this reaction.

Outline why the value obtained in (b)(i) might differ from a value calculated using ΔH_f data.

Outline why the value obtained in (b)(i) might differ from a value calculated using ΔH_f data.

Calculate the enthalpy change, ΔH^⦵, for the Haber–Bosch process, in kJ, using the following data.

$∆H_{ \mathrm{f}}^{⦵}\left({\mathrm{NH}}_3\right)=-46.2 \mathrm{kJ} {\mathrm{mol}}^{-1}$.

Outline why ozone in the stratosphere is important.

Draw and label an enthalpy level diagram for this reaction.

Draw and label an enthalpy level diagram for this reaction.

The IR spectrum and low resolution ¹H NMR spectrum of the actual product formed are shown.

Deduce whether the product is A or B, using evidence from these spectra together with sections 26 and 27 of the  data booklet.

Identity of product:

One piece of evidence from IR:

One piece of evidence from ¹H NMR:

Outline why ozone in the stratosphere is important.

The IR spectrum and low resolution ¹H NMR spectrum of the actual product formed are shown.

Deduce whether the product is A or B, using evidence from these spectra together with sections 26 and 27 of the  data booklet.

Identity of product:

One piece of evidence from IR:

One piece of evidence from ¹H NMR:

The IR spectrum and low resolution ¹H NMR spectrum of the actual product formed are shown.

Deduce whether the product is A or B, using evidence from these spectra together with sections 26 and 27 of the  data booklet.

Identity of product:

One piece of evidence from IR:

One piece of evidence from ¹H NMR:

Predict, giving a reason, how the final enthalpy of reaction calculated from this experiment would compare with the theoretical value.

Predict, giving a reason, how the final enthalpy of reaction calculated from this experiment would compare with the theoretical value.

Predict, giving a reason, how the final enthalpy of reaction calculated from this experiment would compare with the theoretical value.

Outline why ozone in the stratosphere is important.

The formula q = mcΔT was used to calculate the energy released. The values used in the calculation were m = 25.00 g, c = 4.18 J g⁻¹ K⁻¹.

State an assumption made when using these values for m and c.

The maximum temperature used to calculate the enthalpy of reaction was chosen at a point on the extrapolated (dotted) line.

State the maximum temperature which should be used and outline one assumption made in choosing this temperature on the extrapolated line.

Maximum temperature:

Assumption:

The maximum temperature used to calculate the enthalpy of reaction was chosen at a point on the extrapolated (dotted) line.

State the maximum temperature which should be used and outline one assumption made in choosing this temperature on the extrapolated line.

Maximum temperature:

Assumption:

The maximum temperature used to calculate the enthalpy of reaction was chosen at a point on the extrapolated (dotted) line.

State the maximum temperature which should be used and outline one assumption made in choosing this temperature on the extrapolated line.

Maximum temperature:

Assumption:

The formula q = mcΔT was used to calculate the energy released. The values used in the calculation were m = 25.00 g, c = 4.18 J g⁻¹ K⁻¹.

State an assumption made when using these values for m and c.

State what point Y on the graph represents.

To determine the enthalpy of reaction the experiment was carried out five times. The same volume and concentration of copper(II) sulfate was used but the mass of zinc was different each time. Suggest, with a reason, if zinc or copper(II) sulfate should be in excess for each trial.

The formula q = mcΔT was used to calculate the energy released. The values used in the calculation were m = 25.00 g, c = 4.18 J g⁻¹ K⁻¹.

State an assumption made when using these values for m and c.

To determine the enthalpy of reaction the experiment was carried out five times. The same volume and concentration of copper(II) sulfate was used but the mass of zinc was different each time. Suggest, with a reason, if zinc or copper(II) sulfate should be in excess for each trial.

To determine the enthalpy of reaction the experiment was carried out five times. The same volume and concentration of copper(II) sulfate was used but the mass of zinc was different each time. Suggest, with a reason, if zinc or copper(II) sulfate should be in excess for each trial.

Methane undergoes incomplete combustion.

2CH₄ (g) + 3O₂ (g) → 2CO (g) + 4H₂O (g)

What is the enthalpy change, in kJ, using the bond enthalpy data given below?

A. [2(1077) + 4(463)] − [2(414) + 3(498)]

B. [2(414) + 3(498)] − [2(1077) + 4(463)]

C. [8(414) + 3(498)] − [2(1077) + 8(463)]

D. [2(1077) + 8(463)] − [8(414) + 3(498)]

State what point Y on the graph represents.

State what point Y on the graph represents.

What is the enthalpy change of reaction for the following equation?

C₂H₄ (g) + H₂ (g) → C₂H₆ (g)

C₂H₄ (g) + 3O₂ (g) → 2CO₂ (g) + 2H₂O (l)        ΔH = x

C₂H₆ (g) + $\frac{7}{2}$O₂ (g) → 2CO₂ (g) + 3H₂O (l)    ΔH = y

H₂ (g) + $\frac{1}{2}$O₂ (g) → H₂O (l)                           ΔH = z

A. x + y + z

B. −x − y + z

C. x − y − z

D. x − y + z

What is the enthalpy change of reaction for the following equation?

C₂H₄ (g) + H₂ (g) → C₂H₆ (g)

C₂H₄ (g) + 3O₂ (g) → 2CO₂ (g) + 2H₂O (l)        ΔH = x

C₂H₆ (g) + $\frac{7}{2}$O₂ (g) → 2CO₂ (g) + 3H₂O (l)    ΔH = y

H₂ (g) + $\frac{1}{2}$O₂ (g) → H₂O (l)                           ΔH = z

A. x + y + z

B. −x − y + z

C. x − y − z

D. x − y + z

Methane undergoes incomplete combustion.

2CH₄ (g) + 3O₂ (g) → 2CO (g) + 4H₂O (g)

What is the enthalpy change, in kJ, using the bond enthalpy data given below?

A. [2(1077) + 4(463)] − [2(414) + 3(498)]

B. [2(414) + 3(498)] − [2(1077) + 4(463)]

C. [8(414) + 3(498)] − [2(1077) + 8(463)]

D. [2(1077) + 8(463)] − [8(414) + 3(498)]

The formula q = mcΔT was used to calculate the energy released. The values used in the calculation were m = 25.00 g, c = 4.18 J g⁻¹ K⁻¹.

State an assumption made when using these values for m and c.

The formula q = mcΔT was used to calculate the energy released. The values used in the calculation were m = 25.00 g, c = 4.18 J g⁻¹ K⁻¹.

State an assumption made when using these values for m and c.

The formula q = mcΔT was used to calculate the energy released. The values used in the calculation were m = 25.00 g, c = 4.18 J g⁻¹ K⁻¹.

State an assumption made when using these values for m and c.

Outline why ozone in the stratosphere is important.

The enthalpy change for the reaction to produce B is −213 kJ. Predict, giving a reason, which product is the most stable.

Outline why ozone in the stratosphere is important.

Outline why ozone in the stratosphere is important.

Determine the enthalpy change, ΔH, in kJ, for this reaction using data from the table and section 12 of the data booklet.

The enthalpy change for the reaction to produce B is −213 kJ. Predict, giving a reason, which product is the most stable.

Determine the enthalpy change, ΔH, in kJ, for this reaction using data from the table and section 12 of the data booklet.

Determine the enthalpy change, ΔH, in kJ, for this reaction using data from the table and section 12 of the data booklet.

To determine the enthalpy of reaction the experiment was carried out five times. The same volume and concentration of copper(II) sulfate was used but the mass of zinc was different each time. Suggest, with a reason, if zinc or copper(II) sulfate should be in excess for each trial.

To determine the enthalpy of reaction the experiment was carried out five times. The same volume and concentration of copper(II) sulfate was used but the mass of zinc was different each time. Suggest, with a reason, if zinc or copper(II) sulfate should be in excess for each trial.

To determine the enthalpy of reaction the experiment was carried out five times. The same volume and concentration of copper(II) sulfate was used but the mass of zinc was different each time. Suggest, with a reason, if zinc or copper(II) sulfate should be in excess for each trial.

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

The enthalpy change for the reaction to produce B is −213 kJ. Predict, giving a reason, which product is the most stable.

Methane undergoes incomplete combustion.

2CH₄ (g) + 3O₂ (g) → 2CO (g) + 4H₂O (g)

What is the enthalpy change, in kJ, using the bond enthalpy data given below?

A. [2(1077) + 4(463)] − [2(414) + 3(498)]

B. [2(414) + 3(498)] − [2(1077) + 4(463)]

C. [8(414) + 3(498)] − [2(1077) + 8(463)]

D. [2(1077) + 8(463)] − [8(414) + 3(498)]

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

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

Methane undergoes incomplete combustion.

2CH₄ (g) + 3O₂ (g) → 2CO (g) + 4H₂O (g)

What is the enthalpy change, in kJ, using the bond enthalpy data given below?

A. [2(1077) + 4(463)] − [2(414) + 3(498)]

B. [2(414) + 3(498)] − [2(1077) + 4(463)]

C. [8(414) + 3(498)] − [2(1077) + 8(463)]

D. [2(1077) + 8(463)] − [8(414) + 3(498)]

Determine the enthalpy of combustion of this compound, in kJ mol⁻¹, using data from section 11 of the data booklet.

Consider the following equations.

2Al (s) + $\frac{3}{2}$O₂ (g) → Al₂O₃ (s)    ΔH^Ɵ = −1670 kJ
Mn (s) + O₂ (g) → MnO₂ (s)    ΔH^Ɵ = −520 kJ

What is the standard enthalpy change, in kJ, of the reaction below?

4Al (s) + 3MnO₂ (s) → 2Al₂O₃ (s) + 3Mn (s)

A. −1670 + 520

B. $\frac{3}{2}$(−1670) + 3(520)

C. 2(−1670) + 3(−520)

D. 2(−1670) + 3(520)

Consider the following equations.

2Al (s) + $\frac{3}{2}$O₂ (g) → Al₂O₃ (s)    ΔH^Ɵ = −1670 kJ
Mn (s) + O₂ (g) → MnO₂ (s)    ΔH^Ɵ = −520 kJ

What is the standard enthalpy change, in kJ, of the reaction below?

4Al (s) + 3MnO₂ (s) → 2Al₂O₃ (s) + 3Mn (s)

A. −1670 + 520

B. $\frac{3}{2}$(−1670) + 3(520)

C. 2(−1670) + 3(−520)

D. 2(−1670) + 3(520)

What is the enthalpy change of the reaction?

C₆H₁₄ (l) → C₂H₄ (g) + C₄H₁₀ (g)

A.  + 1411 + 2878 + 4163

B.  + 1411 − 2878 − 4163

C.  + 1411 + 2878 − 4163

D.  − 1411 − 2878 + 4163

Which is correct for the reaction?

2Al (s) + 6HCl (aq) → 2AlCl₃ (aq) + 3H₂ (g)         ΔH = −1049 kJ

A. Reactants are less stable than products and the reaction is endothermic.

B. Reactants are more stable than products and the reaction is endothermic.

C. Reactants are more stable than products and the reaction is exothermic.

D. Reactants are less stable than products and the reaction is exothermic.

Which is correct for the reaction?

2Al (s) + 6HCl (aq) → 2AlCl₃ (aq) + 3H₂ (g)         ΔH = −1049 kJ

A. Reactants are less stable than products and the reaction is endothermic.

B. Reactants are more stable than products and the reaction is endothermic.

C. Reactants are more stable than products and the reaction is exothermic.

D. Reactants are less stable than products and the reaction is exothermic.

Determine the enthalpy of combustion of this compound, in kJ mol⁻¹, using data from section 11 of the data booklet.

The diagram shows the Maxwell–Boltzmann distribution and potential energy profile for the reaction without a catalyst.

Annotate both charts to show the activation energy for the catalysed reaction, using the label E_{a (cat)}.

What is the enthalpy change of the reaction?

C₆H₁₄ (l) → C₂H₄ (g) + C₄H₁₀ (g)

A.  + 1411 + 2878 + 4163

B.  + 1411 − 2878 − 4163

C.  + 1411 + 2878 − 4163

D.  − 1411 − 2878 + 4163

Determine the enthalpy of combustion of this compound, in kJ mol⁻¹, using data from section 11 of the data booklet.

Copper(II) chloride is used as a catalyst in the production of chlorine from hydrogen chloride.

4HCl (g) + O₂ (g) → 2Cl₂ (g) + 2H₂O (g)

Calculate the standard enthalpy change, ΔH^θ, in kJ, for this reaction, using section 12 of the data booklet.

Determine the enthalpy of combustion of the organic product in (b), in kJ mol⁻¹, using data from section 11 of the data booklet.

Copper(II) chloride is used as a catalyst in the production of chlorine from hydrogen chloride.

4HCl (g) + O₂ (g) → 2Cl₂ (g) + 2H₂O (g)

Calculate the standard enthalpy change, ΔH^θ, in kJ, for this reaction, using section 12 of the data booklet.

Copper(II) chloride is used as a catalyst in the production of chlorine from hydrogen chloride.

4HCl (g) + O₂ (g) → 2Cl₂ (g) + 2H₂O (g)

Calculate the standard enthalpy change, ΔH^θ, in kJ, for this reaction, using section 12 of the data booklet.

The diagram shows the Maxwell–Boltzmann distribution and potential energy profile for the reaction without a catalyst.

Annotate both charts to show the activation energy for the catalysed reaction, using the label E_{a (cat)}.

The diagram shows the Maxwell–Boltzmann distribution and potential energy profile for the reaction without a catalyst.

Annotate both charts to show the activation energy for the catalysed reaction, using the label E_{a (cat)}.

Determine the enthalpy of combustion of the organic product in (b), in kJ mol⁻¹, using data from section 11 of the data booklet.

Copper(II) chloride is used as a catalyst in the production of chlorine from hydrogen chloride.

4HCl (g) + O₂ (g) → 2Cl₂ (g) + 2H₂O (g)

Calculate the standard enthalpy change, ΔH^θ, in kJ, for this reaction, using section 12 of the data booklet.

Which equation represents the N–H bond enthalpy in NH₃?

A.  NH₃ (g) → N (g) + 3H (g)

B.  $\frac{1}{3}$NH₃ (g) → $\frac{1}{3}$N (g) + H (g)

C.  NH₃ (g) → $\frac{1}{2}$N₂ (g) + $\frac{3}{2}$H₂ (g)

D.  NH₃ (g) → •NH₂ (g) + •H (g)

Which equation represents the N–H bond enthalpy in NH₃?

A.  NH₃ (g) → N (g) + 3H (g)

B.  $\frac{1}{3}$NH₃ (g) → $\frac{1}{3}$N (g) + H (g)

C.  NH₃ (g) → $\frac{1}{2}$N₂ (g) + $\frac{3}{2}$H₂ (g)

D.  NH₃ (g) → •NH₂ (g) + •H (g)

Determine the enthalpy of combustion of the organic product in (b), in kJ mol⁻¹, using data from section 11 of the data booklet.

Copper(II) chloride is used as a catalyst in the production of chlorine from hydrogen chloride.

4HCl (g) + O₂ (g) → 2Cl₂ (g) + 2H₂O (g)

Calculate the standard enthalpy change, ΔH^θ, in kJ, for this reaction, using section 12 of the data booklet.

Copper(II) chloride is used as a catalyst in the production of chlorine from hydrogen chloride.

4HCl (g) + O₂ (g) → 2Cl₂ (g) + 2H₂O (g)

Calculate the standard enthalpy change, ΔH^θ, in kJ, for this reaction, using section 12 of the data booklet.

The diagram shows the Maxwell–Boltzmann distribution and potential energy profile for the reaction without a catalyst.

Annotate both charts to show the activation energy for the catalysed reaction, using the label E_{a (cat)}.

The diagram shows the Maxwell–Boltzmann distribution and potential energy profile for the reaction without a catalyst.

Annotate both charts to show the activation energy for the catalysed reaction, using the label E_{a (cat)}.

The diagram shows the Maxwell–Boltzmann distribution and potential energy profile for the reaction without a catalyst.

Annotate both charts to show the activation energy for the catalysed reaction, using the label E_{a (cat)}.

The mass of the contents of the cold pack is 25.32 g and its initial temperature is 25.2 °C. Once the contents are mixed, the temperature drops to 0.8 °C.

Calculate the energy, in J, absorbed by the dissolution of ammonium nitrate in water within the cold pack. Assume the specific heat capacity of the solution is 4.18 J g⁻¹ K⁻¹. Use section 1 of the data booklet.

What is the value for enthalpy of formation of methane from the given enthalpies of combustion?

C (s) + O₂ (g) → CO₂ (g)                               ΔH = −394 kJ mol⁻¹

H₂ (g) + $\frac{1}{2}$O₂ (g) → H₂O (l)                            ΔH = −286 kJ mol⁻¹

CH₄ (g) + 2O₂ (g) → CO₂ (g) + 2H₂O (l)         ΔH = −891 kJ mol⁻¹

A.   (−394 − 286 − 891) kJ mol⁻¹

B.   (−394 − (2 × 286) − 891) kJ mol⁻¹

C.   (−394 − 286 + 891) kJ mol⁻¹

D.   (−394 − (2 × 286) + 891) kJ mol⁻¹

What is the value for enthalpy of formation of methane from the given enthalpies of combustion?

C (s) + O₂ (g) → CO₂ (g)                               ΔH = −394 kJ mol⁻¹

H₂ (g) + $\frac{1}{2}$O₂ (g) → H₂O (l)                            ΔH = −286 kJ mol⁻¹

CH₄ (g) + 2O₂ (g) → CO₂ (g) + 2H₂O (l)         ΔH = −891 kJ mol⁻¹

A.   (−394 − 286 − 891) kJ mol⁻¹

B.   (−394 − (2 × 286) − 891) kJ mol⁻¹

C.   (−394 − 286 + 891) kJ mol⁻¹

D.   (−394 − (2 × 286) + 891) kJ mol⁻¹

Calculate the standard enthalpy change, $\text{Δ}{H}^{⦵}$, of the reaction. Use section 12 of the data booklet.

$\text{Δ}{H}_f^{⦵}$ ammonium nitrate = −366 kJ mol⁻¹

$\text{Δ}{H}_f^{⦵}$ dinitrogen monoxide = 82 kJ mol⁻¹

The mass of the contents of the cold pack is 25.32 g and its initial temperature is 25.2 °C. Once the contents are mixed, the temperature drops to 0.8 °C.

Calculate the energy, in J, absorbed by the dissolution of ammonium nitrate in water within the cold pack. Assume the specific heat capacity of the solution is 4.18 J g⁻¹ K⁻¹. Use section 1 of the data booklet.

The mass of the contents of the cold pack is 25.32 g and its initial temperature is 25.2 °C. Once the contents are mixed, the temperature drops to 0.8 °C.

Calculate the energy, in J, absorbed by the dissolution of ammonium nitrate in water within the cold pack. Assume the specific heat capacity of the solution is 4.18 J g⁻¹ K⁻¹. Use section 1 of the data booklet.

The mass of the contents of the cold pack is 25.32 g and its initial temperature is 25.2 °C. Once the contents are mixed, the temperature drops to 0.8 °C.

Calculate the energy, in J, absorbed by the dissolution of ammonium nitrate in water within the cold pack. Assume the specific heat capacity of the solution is 4.18 J g⁻¹ K⁻¹. Use section 1 of the data booklet.

The change in enthalpy when ammonium nitrate dissolves in water is 25.69 kJ mol⁻¹. Determine the mass of ammonium nitrate in the cold pack using your answer obtained in (e)(i) and section 6 of the data booklet.

If you did not obtain an answer in (e)(i), use 3.11 × 10³ J, although this is not the correct answer.

The change in enthalpy when ammonium nitrate dissolves in water is 25.69 kJ mol⁻¹. Determine the mass of ammonium nitrate in the cold pack using your answer obtained in (e)(i) and section 6 of the data booklet.

If you did not obtain an answer in (e)(i), use 3.11 × 10³ J, although this is not the correct answer.

The change in enthalpy when ammonium nitrate dissolves in water is 25.69 kJ mol⁻¹. Determine the mass of ammonium nitrate in the cold pack using your answer obtained in (e)(i) and section 6 of the data booklet.

If you did not obtain an answer in (e)(i), use 3.11 × 10³ J, although this is not the correct answer.

Calculate the standard enthalpy change, $\text{Δ}{H}^{⦵}$, of the reaction. Use section 12 of the data booklet.

$\text{Δ}{H}_f^{⦵}$ ammonium nitrate = −366 kJ mol⁻¹

$\text{Δ}{H}_f^{⦵}$ dinitrogen monoxide = 82 kJ mol⁻¹

Calculate the standard enthalpy change, $\text{Δ}{H}^{⦵}$, of the reaction. Use section 12 of the data booklet.

$\text{Δ}{H}_f^{⦵}$ ammonium nitrate = −366 kJ mol⁻¹

$\text{Δ}{H}_f^{⦵}$ dinitrogen monoxide = 82 kJ mol⁻¹

The mass of the contents of the cold pack is 25.32 g and its initial temperature is 25.2 °C. Once the contents are mixed, the temperature drops to 0.8 °C.

Calculate the energy, in J, absorbed by the dissolution of ammonium nitrate in water within the cold pack. Assume the specific heat capacity of the solution is 4.18 J g⁻¹ K⁻¹. Use section 1 of the data booklet.

Calculate the standard enthalpy change, $\text{Δ}{H}^{⦵}$, of the reaction. Use section 12 of the data booklet.

$\text{Δ}{H}_f^{⦵}$ ammonium nitrate = −366 kJ mol⁻¹

$\text{Δ}{H}_f^{⦵}$ dinitrogen monoxide = 82 kJ mol⁻¹

The mass of the contents of the cold pack is 25.32 g and its initial temperature is 25.2 °C. Once the contents are mixed, the temperature drops to 0.8 °C.

Calculate the energy, in J, absorbed by the dissolution of ammonium nitrate in water within the cold pack. Assume the specific heat capacity of the solution is 4.18 J g⁻¹ K⁻¹. Use section 1 of the data booklet.

Determine the mass of ammonium nitrate in the cold pack using your answer obtained in (d)(i) and and sections 6 and 19 of the data booklet.

If you did not obtain an answer in (d)(i), use 3.11 × 10³ J, although this is not the correct answer.

Calculate the standard enthalpy change, $\text{Δ}{H}^{⦵}$, of the reaction. Use section 12 of the data booklet.

$\text{Δ}{H}_f^{⦵}$ ammonium nitrate = −366 kJ mol⁻¹

$\text{Δ}{H}_f^{⦵}$ dinitrogen monoxide = 82 kJ mol⁻¹

Calculate the standard enthalpy change, $\text{Δ}{H}^{⦵}$, of the reaction. Use section 12 of the data booklet.

$\text{Δ}{H}_f^{⦵}$ ammonium nitrate = −366 kJ mol⁻¹

$\text{Δ}{H}_f^{⦵}$ dinitrogen monoxide = 82 kJ mol⁻¹

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?

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

Determine the mass of ammonium nitrate in the cold pack using your answer obtained in (d)(i) and and sections 6 and 19 of the data booklet.

If you did not obtain an answer in (d)(i), use 3.11 × 10³ J, although this is not the correct answer.

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).

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

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

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?

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 mass of ammonium nitrate in the cold pack using your answer obtained in (d)(i) and and sections 6 and 19 of the data booklet.

If you did not obtain an answer in (d)(i), use 3.11 × 10³ J, although this is not the correct answer.

Outline why bond enthalpy values are not valid in calculations such as that in (c)(i).

Determine the enthalpy change, ΔH, in kJ, for this reaction using data from the table and section 12 of the data booklet.

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

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

Outline why bond enthalpy values are not valid in calculations such as that in (c)(i).

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

Estimate the time at which the powdered zinc was placed in the beaker.

Estimate the time at which the powdered zinc was placed in the beaker.

Estimate the time at which the powdered zinc was placed in the beaker.

Determine the enthalpy change, ΔH, in kJ, for this reaction using data from the table and section 12 of the data booklet.

Determine the enthalpy change, ΔH, in kJ, for this reaction using data from the table and section 12 of the data booklet.

Outline why bond enthalpy values are not valid in calculations such as that in (c)(i).

State what point Y on the graph represents.

State what point Y on the graph represents.

State what point Y on the graph represents.

What is the enthalpy of combustion, ΔH_c, of ethanol in kJ mol⁻¹?
Maximum temperature of water: 30.0°C
Initial temperature of water: 20.0°C
Mass of water in beaker: 100.0 g
Loss in mass of ethanol: 0.230 g
M_r (ethanol): 46.08
Specific heat capacity of water: 4.18 J g⁻¹ K⁻¹
q = mcΔT

A.  $-\frac{100.0\times 4.18\times (10.0\times 273)}{{\displaystyle \frac{0.230}{46.08}}\times 1000}$

B.  $-\frac{0.0230\times 4.18\times 10.0}{{\displaystyle \frac{100.0}{46.08}}\times 1000}$

C.  $-\frac{100.0\times 4.18\times 10.0}{{\displaystyle \frac{0.230}{46.08}}\times 1000}$

D.  $-\frac{100.0\times 4.18\times 10.0}{{\displaystyle \frac{0.230}{46.08}}}$

The maximum temperature used to calculate the enthalpy of reaction was chosen at a point on the extrapolated (dotted) line.

State the maximum temperature which should be used and outline one assumption made in choosing this temperature on the extrapolated line.

Maximum temperature:

Assumption:

The maximum temperature used to calculate the enthalpy of reaction was chosen at a point on the extrapolated (dotted) line.

State the maximum temperature which should be used and outline one assumption made in choosing this temperature on the extrapolated line.

Maximum temperature:

Assumption:

The maximum temperature used to calculate the enthalpy of reaction was chosen at a point on the extrapolated (dotted) line.

State the maximum temperature which should be used and outline one assumption made in choosing this temperature on the extrapolated line.

Maximum temperature:

Assumption:

Outline why bond enthalpy values are not valid in calculations such as that in (g)(i).

What is the enthalpy of combustion, ΔH_c, of ethanol in kJ mol⁻¹?
Maximum temperature of water: 30.0°C
Initial temperature of water: 20.0°C
Mass of water in beaker: 100.0 g
Loss in mass of ethanol: 0.230 g
M_r (ethanol): 46.08
Specific heat capacity of water: 4.18 J g⁻¹ K⁻¹
q = mcΔT

A.  $-\frac{100.0\times 4.18\times (10.0\times 273)}{{\displaystyle \frac{0.230}{46.08}}\times 1000}$

B.  $-\frac{0.0230\times 4.18\times 10.0}{{\displaystyle \frac{100.0}{46.08}}\times 1000}$

C.  $-\frac{100.0\times 4.18\times 10.0}{{\displaystyle \frac{0.230}{46.08}}\times 1000}$

D.  $-\frac{100.0\times 4.18\times 10.0}{{\displaystyle \frac{0.230}{46.08}}}$

Outline why bond enthalpy values are not valid in calculations such as that in (g)(i).

Outline why bond enthalpy values are not valid in calculations such as that in (g)(i).

Predict, giving a reason, how the final enthalpy of reaction calculated from this experiment would compare with the theoretical value.

Predict, giving a reason, how the final enthalpy of reaction calculated from this experiment would compare with the theoretical value.

Predict, giving a reason, how the final enthalpy of reaction calculated from this experiment would compare with the theoretical value.

Which statement is correct?

A.  ${\mathrm{O}}_3$ bond dissociation occurs at a longer wavelength of light than ${\mathrm{O}}_2$ bond dissociation.

B.  ${\mathrm{O}}_3$ bond dissociation occurs at a higher energy than ${\mathrm{O}}_2$ bond dissociation.

C.  ${\mathrm{O}}_3$ bond lengths are shorter than ${\mathrm{O}}_2$ bond lengths.

D.  ${\mathrm{O}}_3$ bond dissociation occurs at a higher frequency of light than ${\mathrm{O}}_2$ bond dissociation.

Which statement is correct?

A.  ${\mathrm{O}}_3$ bond dissociation occurs at a longer wavelength of light than ${\mathrm{O}}_2$ bond dissociation.

B.  ${\mathrm{O}}_3$ bond dissociation occurs at a higher energy than ${\mathrm{O}}_2$ bond dissociation.

C.  ${\mathrm{O}}_3$ bond lengths are shorter than ${\mathrm{O}}_2$ bond lengths.

D.  ${\mathrm{O}}_3$ bond dissociation occurs at a higher frequency of light than ${\mathrm{O}}_2$ bond dissociation.

An allotrope of molecular oxygen is ozone. Compare, giving a reason, the bond enthalpies of the O to O bonds in O₂ and O₃.

An allotrope of molecular oxygen is ozone. Compare, giving a reason, the bond enthalpies of the O to O bonds in O₂ and O₃.

An allotrope of molecular oxygen is ozone. Compare, giving a reason, the bond enthalpies of the O to O bonds in O₂ and O₃.

Calculate the enthalpy change of reaction, ΔH, in kJ, for the decomposition of calcium carbonate.

Determine the enthalpy change, ΔH, in kJ. Use section 11 of the data booklet.

Bond enthalpy of CO = 1077 kJ mol⁻¹.

Calculate the enthalpy change of reaction, ΔH, in kJ, for the decomposition of calcium carbonate.

Determine the enthalpy change, ΔH, in kJ. Use section 11 of the data booklet.

Bond enthalpy of CO = 1077 kJ mol⁻¹.

Determine the enthalpy change, ΔH, in kJ. Use section 11 of the data booklet.

Bond enthalpy of CO = 1077 kJ mol⁻¹.

Calculate the enthalpy change of reaction, ΔH, in kJ, for the decomposition of calcium carbonate.

Sketch an energy profile for the decomposition of calcium carbonate based on your answer to b(i), labelling the axes and activation energy, E_a.

Calculate the enthalpy change of the reaction, ΔH, using section 11 of the data booklet.

Sketch an energy profile for the decomposition of calcium carbonate based on your answer to b(i), labelling the axes and activation energy, E_a.

Determine the enthalpy change, ΔH, for the Haber–Bosch process, in kJ. Use Section 11 of the data booklet.

Sketch an energy profile for the decomposition of calcium carbonate based on your answer to b(i), labelling the axes and activation energy, E_a.

Calculate the enthalpy change of the reaction, ΔH, using section 11 of the data booklet.

Calculate the enthalpy change of the reaction, ΔH, using section 11 of the data booklet.

Calculate the enthalpy change of the reaction, ΔH, using section 11 of the data booklet.

Calculate the enthalpy change of the reaction, ΔH, using section 11 of the data booklet.

Discuss two different ways to reduce the environmental impact of energy production from coal.

Determine the enthalpy change, ΔH, for the Haber–Bosch process, in kJ. Use Section 11 of the data booklet.

Determine the enthalpy change, ΔH, for the Haber–Bosch process, in kJ. Use Section 11 of the data booklet.

Calculate the enthalpy change of the reaction, ΔH, using section 11 of the data booklet.

Discuss two different ways to reduce the environmental impact of energy production from coal.

Discuss two different ways to reduce the environmental impact of energy production from coal.

Suggest why the values obtained in (d)(i) and (d)(ii) differ.

Suggest why the values obtained in (d)(i) and (d)(ii) differ.

Suggest why the values obtained in (d)(i) and (d)(ii) differ.

What happens to the average kinetic energy, KE, of the particles in a gas when the absolute temperature is doubled?

$\mathrm{KE}=\frac{1}{2}\hspace{0.17em}{\mathrm{mv}}^2$

A.  Increases by a factor of 2

B.  Decreases by a factor of 2

C.  Increases by a factor of 4

D.  Decreases by a factor of 4

What happens to the average kinetic energy, KE, of the particles in a gas when the absolute temperature is doubled?

$\mathrm{KE}=\frac{1}{2}\hspace{0.17em}{\mathrm{mv}}^2$

A.  Increases by a factor of 2

B.  Decreases by a factor of 2

C.  Increases by a factor of 4

D.  Decreases by a factor of 4

What happens to the average kinetic energy, KE, of the particles in a gas when the absolute temperature is doubled?

$\mathrm{KE}=\frac{1}{2}\hspace{0.17em}{\mathrm{mv}}^2$

A.  Increases by a factor of 2

B.  Decreases by a factor of 2

C.  Increases by a factor of 4

D.  Decreases by a factor of 4

What happens to the average kinetic energy, KE, of the particles in a gas when the absolute temperature is doubled?

$\mathrm{KE}=\frac{1}{2}\hspace{0.17em}{\mathrm{mv}}^2$

A.  Increases by a factor of 2

B.  Decreases by a factor of 2

C.  Increases by a factor of 4

D.  Decreases by a factor of 4

Which calculation determines the initial rate of this reaction?

A.  $\frac{0.40-0.19}{20-0}$

B.  $\frac{0.40-0.10}{40-0}$

C.  $\frac{0.40-0}{140-0}$

D.  $\frac{0.40-0.20}{10-0}$

Which calculation determines the initial rate of this reaction?

A.  $\frac{0.40-0.19}{20-0}$

B.  $\frac{0.40-0.10}{40-0}$

C.  $\frac{0.40-0}{140-0}$

D.  $\frac{0.40-0.20}{10-0}$

20 cm³ of gas A reacts with 20 cm³ of gas B to produce 10 cm³ of gas A_xB_y and 10 cm³ of excess gas A. What are the correct values for subscripts x and y in the empirical formula of the product A_xB_y (g)?

20 cm³ of gas A reacts with 20 cm³ of gas B to produce 10 cm³ of gas A_xB_y and 10 cm³ of excess gas A. What are the correct values for subscripts x and y in the empirical formula of the product A_xB_y (g)?

Deduce the ionic equation, including state symbols, for the reaction of hydrogen chloride gas with water.

Deduce the ionic equation, including state symbols, for the reaction of hydrogen chloride gas with water.

This reaction has an equilibrium constant K_c = 650 at a certain temperature.

NO₂ (g) + SO₂ (g) ⇌ NO + SO₃ (g)

What is the equilibrium constant for the following reaction at the same temperature?

$\frac{1}{2}\mathrm{NO}\hspace{0.17em}\left(\mathrm{g}\right)+\frac{1}{2}{\mathrm{SO}}_3\hspace{0.17em}\left(\mathrm{g}\right)\rightleftharpoons \frac{1}{2}{\mathrm{NO}}_2\hspace{0.17em}\left(\mathrm{g}\right)+\frac{1}{2}{\mathrm{SO}}_2\hspace{0.17em}\left(\mathrm{g}\right)$

A.  $\sqrt{650}$

B.  $\frac{1}{650}$

C.  $\frac{1}{\sqrt{650}}$

D.  $\frac{1}{2}\times 650$

This reaction has an equilibrium constant K_c = 650 at a certain temperature.

NO₂ (g) + SO₂ (g) ⇌ NO + SO₃ (g)

What is the equilibrium constant for the following reaction at the same temperature?

$\frac{1}{2}\mathrm{NO}\hspace{0.17em}\left(\mathrm{g}\right)+\frac{1}{2}{\mathrm{SO}}_3\hspace{0.17em}\left(\mathrm{g}\right)\rightleftharpoons \frac{1}{2}{\mathrm{NO}}_2\hspace{0.17em}\left(\mathrm{g}\right)+\frac{1}{2}{\mathrm{SO}}_2\hspace{0.17em}\left(\mathrm{g}\right)$

A.  $\sqrt{650}$

B.  $\frac{1}{650}$

C.  $\frac{1}{\sqrt{650}}$

D.  $\frac{1}{2}\times 650$

Deduce the ionic equation, including state symbols, for the reaction of hydrogen chloride gas with water.

What is the relationship between acid and base dissociation constants in a conjugate acid–base pair?

A.  $K\mathrm{a}\times K\mathrm{b}=K\mathrm{w}$

B.  $\frac{Ka}{Kb}=K\mathrm{w}$

C.  $\mathrm{p}K\mathrm{a}\times \mathrm{p}K\mathrm{b}=\mathrm{p}K\mathrm{w}$

D.  $\frac{pKa}{pKb}=\mathrm{p}K\mathrm{w}$

20 cm³ of gas A reacts with 20 cm³ of gas B to produce 10 cm³ of gas A_xB_y and 10 cm³ of excess gas A. What are the correct values for subscripts x and y in the empirical formula of the product A_xB_y (g)?

20 cm³ of gas A reacts with 20 cm³ of gas B to produce 10 cm³ of gas A_xB_y and 10 cm³ of excess gas A. What are the correct values for subscripts x and y in the empirical formula of the product A_xB_y (g)?

Which are the correct sequences of increasing bond strengths and bond lengths between two carbon atoms?

What is the relationship between acid and base dissociation constants in a conjugate acid–base pair?

A.  $K\mathrm{a}\times K\mathrm{b}=K\mathrm{w}$

B.  $\frac{Ka}{Kb}=K\mathrm{w}$

C.  $\mathrm{p}K\mathrm{a}\times \mathrm{p}K\mathrm{b}=\mathrm{p}K\mathrm{w}$

D.  $\frac{pKa}{pKb}=\mathrm{p}K\mathrm{w}$

The concentration of methanoic acid was found by titration with a 0.200 mol dm⁻³ standard solution of sodium hydroxide, NaOH (aq), using an indicator to determine the end point.

Calculate the pH of the sodium hydroxide solution.

Nitrogen (IV) oxide exists in equilibrium with dinitrogen tetroxide, N₂O₄(g), which is colourless.

2NO₂ (g) ⇌ N₂O₄ (g)

Nitrogen (IV) oxide exists in equilibrium with dinitrogen tetroxide, N₂O₄(g), which is colourless.

2NO₂ (g) ⇌ N₂O₄ (g)

Which are the correct sequences of increasing bond strengths and bond lengths between two carbon atoms?

The concentration of methanoic acid was found by titration with a 0.200 mol dm⁻³ standard solution of sodium hydroxide, NaOH (aq), using an indicator to determine the end point.

Calculate the pH of the sodium hydroxide solution.

The concentration of methanoic acid was found by titration with a 0.200 mol dm⁻³ standard solution of sodium hydroxide, NaOH (aq), using an indicator to determine the end point.

Calculate the pH of the sodium hydroxide solution.

Which condition will cause the given equilibrium to shift to the right?

Ag⁺ (aq) + Cl⁻ (aq) ⇌ AgCl (s)

A.  One half of solid AgCl is removed.

B.  Water is added.

C.  Solid NaCl is added.

D.  The system is subjected to increased pressure.

Which condition will cause the given equilibrium to shift to the right?

Ag⁺ (aq) + Cl⁻ (aq) ⇌ AgCl (s)

A.  One half of solid AgCl is removed.

B.  Water is added.

C.  Solid NaCl is added.

D.  The system is subjected to increased pressure.

Nitrogen (IV) oxide exists in equilibrium with dinitrogen tetroxide, N₂O₄(g), which is colourless.

2NO₂ (g) ⇌ N₂O₄ (g)

Nitrogen (IV) oxide exists in equilibrium with dinitrogen tetroxide, N₂O₄(g), which is colourless.

2NO₂ (g) ⇌ N₂O₄ (g)

Nitrogen (IV) oxide exists in equilibrium with dinitrogen tetroxide, N₂O₄(g), which is colourless.

2NO₂ (g) ⇌ N₂O₄ (g)

Nitrogen (IV) oxide exists in equilibrium with dinitrogen tetroxide, N₂O₄(g), which is colourless.

2NO₂ (g) ⇌ N₂O₄ (g)

The concentration of methanoic acid was found by titration with a 0.200 mol dm⁻³ standard solution of sodium hydroxide, NaOH (aq), using an indicator to determine the end point.

The concentration of methanoic acid was found by titration with a 0.200 mol dm⁻³ standard solution of sodium hydroxide, NaOH (aq), using an indicator to determine the end point.

The concentration of methanoic acid was found by titration with a 0.200 mol dm⁻³ standard solution of sodium hydroxide, NaOH (aq), using an indicator to determine the end point.

Deduce the overall rate equation.

Deduce the overall rate equation.

Deduce the overall rate equation.