Topic 8: Acids and bases

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.

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.

Which classification is correct for the reaction?

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

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

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)

State the equation for the reaction of each substance with water.

State the equation for the reaction of each substance with water.

Draw the structure of the conjugate base of benzoic acid showing all the atoms and all the bonds.

The hydrogencarbonate ion, produced in Equilibrium (2), can also act as an acid.

State the formula of its conjugate base.

The reaction of the hydroxide ion with carbon dioxide and with the hydrogencarbonate ion can be represented by Equations 3 and 4.

Equation (3)     OH⁻ (aq) + CO₂ (g) → HCO₃⁻ (aq)
Equation (4)     OH⁻ (aq) + HCO₃⁻ (aq) → H₂O (l) + CO₃²⁻ (aq)

Discuss how these equations show the difference between a Lewis base and a Brønsted–Lowry base.

Equation (3):

Equation (4):

Draw the structure of the conjugate base of benzoic acid showing all the atoms and all the bonds.

The hydrogencarbonate ion, produced in Equilibrium (2), can also act as an acid.

State the formula of its conjugate base.

Which of these acids has the weakest conjugate base?

A.  $\mathrm{HCl}$

B.  ${\mathrm{CH}}_3\mathrm{COOH}$

C.  ${\mathrm{NH}}_4\mathrm{Cl}$

D.  ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COOH}$

Which species is a Lewis acid but not a Brønsted–Lowry acid?

A.  ${\mathrm{Cu}}^{2+}$

B.  ${{\mathrm{NH}}_4}^{+}$

C.  $\mathrm{Cu}$

D.  ${\mathrm{CH}}_3\mathrm{COOH}$

State the formula of the conjugate base of hypochlorous acid.

State the formula of the conjugate base of hypochlorous acid.

Calculate the $K_{\mathrm{b}}$ of the conjugate base of ethanoic acid using sections 2 and 21 of the data booklet.

Which is a Lewis acid, but not a Brønsted-Lowry acid?

A.  ${\text{BF}}_3$

B.  ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$

C.  ${\text{NH}}_3$

D.  ${\text{Cl}}^{-}$

Formulate an equation for the reaction of one mole of phosphoric acid with one mole of sodium hydroxide.

Formulate two equations to show the amphiprotic nature of H₂PO₄⁻.

Formulate an equation for the reaction of one mole of phosphoric acid with one mole of sodium hydroxide.

Formulate two equations to show the amphiprotic nature of H₂PO₄⁻.

Draw the structure of the conjugate base of benzoic acid showing all the atoms and all the bonds.

Draw the structure of the conjugate base of benzoic acid showing all the atoms and all the bonds.

The hydrogencarbonate ion, produced in Equilibrium (2), can also act as an acid.

State the formula of its conjugate base.

The reaction of the hydroxide ion with carbon dioxide and with the hydrogencarbonate ion can be represented by Equations 3 and 4.

Equation (3)     OH⁻ (aq) + CO₂ (g) → HCO₃⁻ (aq)
Equation (4)     OH⁻ (aq) + HCO₃⁻ (aq) → H₂O (l) + CO₃²⁻ (aq)

Discuss how these equations show the difference between a Lewis base and a Brønsted–Lowry base.

Equation (3):

Equation (4):

The hydrogencarbonate ion, produced in Equilibrium (2), can also act as an acid.

State the formula of its conjugate base.

The reaction of the hydroxide ion with carbon dioxide and with the hydrogencarbonate ion can be represented by Equations 3 and 4.

Equation (3)     OH⁻ (aq) + CO₂ (g) → HCO₃⁻ (aq)
Equation (4)     OH⁻ (aq) + HCO₃⁻ (aq) → H₂O (l) + CO₃²⁻ (aq)

Discuss how these equations show the difference between a Lewis base and a Brønsted–Lowry base.

Equation (3):

Equation (4):

Draw the structure of the conjugate base of benzoic acid showing all the atoms and all the bonds.

Draw the structure of the conjugate base of benzoic acid showing all the atoms and all the bonds.

The hydrogencarbonate ion, produced in Equilibrium (2), can also act as an acid.

State the formula of its conjugate base.

The hydrogencarbonate ion, produced in Equilibrium (2), can also act as an acid.

State the formula of its conjugate base.

Which of these acids has the weakest conjugate base?

A.  $\mathrm{HCl}$

B.  ${\mathrm{CH}}_3\mathrm{COOH}$

C.  ${\mathrm{NH}}_4\mathrm{Cl}$

D.  ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COOH}$

Which species is a Lewis acid but not a Brønsted–Lowry acid?

A.  ${\mathrm{Cu}}^{2+}$

B.  ${{\mathrm{NH}}_4}^{+}$

C.  $\mathrm{Cu}$

D.  ${\mathrm{CH}}_3\mathrm{COOH}$

State the formula of the conjugate base of hypochlorous acid.

State the formula of the conjugate base of hypochlorous acid.

State the formula of the conjugate base of hypochlorous acid.

State the formula of the conjugate base of hypochlorous acid.

Calculate the $K_{\mathrm{b}}$ of the conjugate base of ethanoic acid using sections 2 and 21 of the data booklet.

Calculate the $K_{\mathrm{b}}$ of the conjugate base of ethanoic acid using sections 2 and 21 of the data booklet.

Which is a Lewis acid, but not a Brønsted-Lowry acid?

A.  ${\text{BF}}_3$

B.  ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$

C.  ${\text{NH}}_3$

D.  ${\text{Cl}}^{-}$

Formulate an equation for the reaction of one mole of phosphoric acid with one mole of sodium hydroxide.

Formulate two equations to show the amphiprotic nature of H₂PO₄⁻.

Formulate an equation for the reaction of one mole of phosphoric acid with one mole of sodium hydroxide.

Formulate two equations to show the amphiprotic nature of H₂PO₄⁻.

Formulate an equation for the reaction of one mole of phosphoric acid with one mole of sodium hydroxide.

Formulate two equations to show the amphiprotic nature of H₂PO₄⁻.

Formulate an equation for the reaction of one mole of phosphoric acid with one mole of sodium hydroxide.

Formulate two equations to show the amphiprotic nature of H₂PO₄⁻.

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.

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.

Which classification is correct for the reaction?

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

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

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

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)

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

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

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

With which do most acids react?

   I. sodium hydrogen carbonate
   II. magnesium
   III. calcium sulfate

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

An antacid contains calcium carbonate and magnesium carbonate.

Write the equation for the reaction of magnesium carbonate with excess stomach acid.

Which substance will not produce copper(II) chloride when added to dilute hydrochloric acid?

A.  $\mathrm{Cu} \left(\mathrm{s}\right)$

B.  $\mathrm{Cu}\left(\mathrm{OH}{)}_2 \right(\mathrm{s})$

C.  ${\mathrm{CuCO}}_3 \left(\mathrm{s}\right)$

D.  $\mathrm{CuO} \left(\mathrm{s}\right)$

State the $K_{\mathrm{a}}$ expression for ethanoic acid.

Potassium hydroxide solutions can react with carbon dioxide from the air. The solution was made one day prior to using it in the titration.

Predict, giving a reason, the effect of this error on the calculated concentration of ethanoic acid in 5(e).

An additional experiment was conducted in which only the sulfuric acid catalyst was titrated with $\mathrm{NaOH}\hspace{0.17em}\left(\mathrm{aq}\right)$. Outline why this experiment was necessary.

What happens to the amount of hydroxide ions and hydroxide ion concentration when water is added to a solution of NH₃(aq)?

Deduce, giving reasons, whether the reaction of magnesium nitride with water is an acid–base reaction, a redox reaction, neither or both.

Deduce, giving reasons, whether the reaction of magnesium nitride with water is an acid–base reaction, a redox reaction, neither or both.

With which do most acids react?

   I. sodium hydrogen carbonate
   II. magnesium
   III. calcium sulfate

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

An antacid contains calcium carbonate and magnesium carbonate.

Write the equation for the reaction of magnesium carbonate with excess stomach acid.

An antacid contains calcium carbonate and magnesium carbonate.

Write the equation for the reaction of magnesium carbonate with excess stomach acid.

Which substance will not produce copper(II) chloride when added to dilute hydrochloric acid?

A.  $\mathrm{Cu} \left(\mathrm{s}\right)$

B.  $\mathrm{Cu}\left(\mathrm{OH}{)}_2 \right(\mathrm{s})$

C.  ${\mathrm{CuCO}}_3 \left(\mathrm{s}\right)$

D.  $\mathrm{CuO} \left(\mathrm{s}\right)$

State the $K_{\mathrm{a}}$ expression for ethanoic acid.

Potassium hydroxide solutions can react with carbon dioxide from the air. The solution was made one day prior to using it in the titration.

Predict, giving a reason, the effect of this error on the calculated concentration of ethanoic acid in 5(e).

State the $K_{\mathrm{a}}$ expression for ethanoic acid.

Potassium hydroxide solutions can react with carbon dioxide from the air. The solution was made one day prior to using it in the titration.

Predict, giving a reason, the effect of this error on the calculated concentration of ethanoic acid in 5(e).

An additional experiment was conducted in which only the sulfuric acid catalyst was titrated with $\mathrm{NaOH}\hspace{0.17em}\left(\mathrm{aq}\right)$. Outline why this experiment was necessary.

An additional experiment was conducted in which only the sulfuric acid catalyst was titrated with $\mathrm{NaOH}\hspace{0.17em}\left(\mathrm{aq}\right)$. Outline why this experiment was necessary.

What happens to the amount of hydroxide ions and hydroxide ion concentration when water is added to a solution of NH₃(aq)?

Deduce, giving reasons, whether the reaction of magnesium nitride with water is an acid–base reaction, a redox reaction, neither or both.

Deduce, giving reasons, whether the reaction of magnesium nitride with water is an acid–base reaction, a redox reaction, neither or both.

Deduce, giving reasons, whether the reaction of magnesium nitride with water is an acid–base reaction, a redox reaction, neither or both.

Deduce, giving reasons, whether the reaction of magnesium nitride with water is an acid–base reaction, a redox reaction, neither or both.

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

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

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

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

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

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.

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

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

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.

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.

Predict, referring to Equilibrium (2), how the added sodium hydrogencarbonate affects the pH.(Assume pressure and temperature remain constant.)

Which solution is basic at 25 °C?

K_w = 1.0 × 10⁻¹⁴

A. [H⁺] = 1.0 × 10⁻³ mol dm⁻³

B. [OH⁻] = 1.0 × 10⁻¹³ mol dm⁻³

C. solution of pH = 4.00

D. [H₃O⁺] = 1.0 × 10⁻¹³ mol dm⁻³

What is the pH of 0.001 mol dm⁻³ NaOH (aq)?

A. 1

B. 3

C. 11

D. 13

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.

Predict, referring to Equilibrium (2), how the added sodium hydrogencarbonate affects the pH.(Assume pressure and temperature remain constant.)

Which solution is basic at 25 °C?

K_w = 1.0 × 10⁻¹⁴

A. [H⁺] = 1.0 × 10⁻³ mol dm⁻³

B. [OH⁻] = 1.0 × 10⁻¹³ mol dm⁻³

C. solution of pH = 4.00

D. [H₃O⁺] = 1.0 × 10⁻¹³ mol dm⁻³

What is the pH of 0.001 mol dm⁻³ NaOH (aq)?

A. 1

B. 3

C. 11

D. 13

Calculate the pH of a buffer solution which contains 0.20 mol dm⁻³ ethanoic acid and 0.50 mol dm⁻³ sodium ethanoate. Use section 1 of the data booklet.

pK_a (ethanoic acid) = 4.76

Explain why a change in pH affects the tertiary structure of an enzyme in solution.

Which apparatus can be used to monitor the rate of this reaction?

${\mathrm{CH}}_3{\mathrm{COCH}}_3 \left(\mathrm{aq}\right)+{\mathrm{I}}_2 \left(\mathrm{aq}\right)\to {\mathrm{CH}}_3{\mathrm{COCH}}_2\mathrm{I} \left(\mathrm{aq}\right)+{\mathrm{H}}^{+} \left(\mathrm{aq}\right)+{\mathrm{I}}^{-} \left(\mathrm{aq}\right)$

1. A pH meter
2. A gas syringe
3. A colorimeter
   

A.  I and II only

B.  I and III only

C.  II and III only

D.  I, II and III

What is the pH of an ammonia solution that has $\left[{\mathrm{OH}}^{-}\right]=1\times {10}^{-4} \mathrm{mol} {\mathrm{dm}}^{-3}$?

A.  $4.0$

B.  $8.0$

C.  $10.0$

D.  $12.0$

Calculate the concentration of ${\mathrm{H}}^{+} \left(\mathrm{aq}\right)$ in a $\mathrm{HClO} \left(\mathrm{aq}\right)$ solution with a $\mathrm{pH}=3.61$.

Calculate the concentration of ${\mathrm{H}}^{+} \left(\mathrm{aq}\right)$ in a $\mathrm{HClO} \left(\mathrm{aq}\right)$ solution with a $\mathrm{pH}=3.61$.

Which solution has a pH of 9?

A.  1.0 × 10⁻⁹ mol dm⁻³ $\text{HCl}$ (aq)

B.  1.0 × 10⁻⁵ mol dm⁻³ $\text{KOH}$ (aq)

C.  1.0 × 10⁻⁹ mol dm⁻³ $\text{KOH}$ (aq)

D.  1.0 × 10⁻⁵ mol dm⁻³ $\text{HCl}$ (aq)

Saturated calcium hydroxide solution is used to test for carbon dioxide. Calculate the pH of a 2.33 × 10⁻²mol dm⁻³ solution of calcium hydroxide, a strong base.

Saturated calcium hydroxide solution is used to test for carbon dioxide. Calculate the pH of a 2.33 × 10⁻²mol dm⁻³ solution of calcium hydroxide, a strong base.

What is the pH of 0.01 mol dm⁻³ KOH (aq)?

A.  1.0

B.  2.0

C.  12.0

D.  13.0

Which of the 0.001 mol dm⁻³ solutions is most likely to have a pH of 11.3?

A.  Ca(OH)₂(aq)

B.  H₃PO₄(aq)

C.  NaOH (aq)

D.  NH₄OH (aq)

Calculate the concentration of hydroxide ions in an ammonia solution with pH = 9.3. Use sections 1 and 2 of the data booklet.

Calculate the concentration of hydroxide ions in an ammonia solution with pH = 9.3. Use sections 1 and 2 of the data booklet.

Calculate the pH of an ammonium nitrate solution with [H₃O⁺] = 1.07× 10⁻⁵ mol dm⁻³. Use section 1 of the data booklet.

Calculate the pH of an ammonium nitrate solution with [H₃O⁺] = 1.07× 10⁻⁵ mol dm⁻³. Use section 1 of the data booklet.

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 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.

Predict, referring to Equilibrium (2), how the added sodium hydrogencarbonate affects the pH.(Assume pressure and temperature remain constant.)

Predict, referring to Equilibrium (2), how the added sodium hydrogencarbonate affects the pH.(Assume pressure and temperature remain constant.)

Which solution is basic at 25 °C?

K_w = 1.0 × 10⁻¹⁴

A. [H⁺] = 1.0 × 10⁻³ mol dm⁻³

B. [OH⁻] = 1.0 × 10⁻¹³ mol dm⁻³

C. solution of pH = 4.00

D. [H₃O⁺] = 1.0 × 10⁻¹³ mol dm⁻³

What is the pH of 0.001 mol dm⁻³ NaOH (aq)?

A. 1

B. 3

C. 11

D. 13

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.

Predict, referring to Equilibrium (2), how the added sodium hydrogencarbonate affects the pH.(Assume pressure and temperature remain constant.)

Predict, referring to Equilibrium (2), how the added sodium hydrogencarbonate affects the pH.(Assume pressure and temperature remain constant.)

Which solution is basic at 25 °C?

K_w = 1.0 × 10⁻¹⁴

A. [H⁺] = 1.0 × 10⁻³ mol dm⁻³

B. [OH⁻] = 1.0 × 10⁻¹³ mol dm⁻³

C. solution of pH = 4.00

D. [H₃O⁺] = 1.0 × 10⁻¹³ mol dm⁻³

What is the pH of 0.001 mol dm⁻³ NaOH (aq)?

A. 1

B. 3

C. 11

D. 13

Calculate the pH of a buffer solution which contains 0.20 mol dm⁻³ ethanoic acid and 0.50 mol dm⁻³ sodium ethanoate. Use section 1 of the data booklet.

pK_a (ethanoic acid) = 4.76

Calculate the pH of a buffer solution which contains 0.20 mol dm⁻³ ethanoic acid and 0.50 mol dm⁻³ sodium ethanoate. Use section 1 of the data booklet.

pK_a (ethanoic acid) = 4.76

Explain why a change in pH affects the tertiary structure of an enzyme in solution.

Explain why a change in pH affects the tertiary structure of an enzyme in solution.

Which apparatus can be used to monitor the rate of this reaction?

${\mathrm{CH}}_3{\mathrm{COCH}}_3 \left(\mathrm{aq}\right)+{\mathrm{I}}_2 \left(\mathrm{aq}\right)\to {\mathrm{CH}}_3{\mathrm{COCH}}_2\mathrm{I} \left(\mathrm{aq}\right)+{\mathrm{H}}^{+} \left(\mathrm{aq}\right)+{\mathrm{I}}^{-} \left(\mathrm{aq}\right)$

1. A pH meter
2. A gas syringe
3. A colorimeter
   

A.  I and II only

B.  I and III only

C.  II and III only

D.  I, II and III

What is the pH of an ammonia solution that has $\left[{\mathrm{OH}}^{-}\right]=1\times {10}^{-4} \mathrm{mol} {\mathrm{dm}}^{-3}$?

A.  $4.0$

B.  $8.0$

C.  $10.0$

D.  $12.0$

Calculate the concentration of ${\mathrm{H}}^{+} \left(\mathrm{aq}\right)$ in a $\mathrm{HClO} \left(\mathrm{aq}\right)$ solution with a $\mathrm{pH}=3.61$.

Calculate the concentration of ${\mathrm{H}}^{+} \left(\mathrm{aq}\right)$ in a $\mathrm{HClO} \left(\mathrm{aq}\right)$ solution with a $\mathrm{pH}=3.61$.

Calculate the concentration of ${\mathrm{H}}^{+} \left(\mathrm{aq}\right)$ in a $\mathrm{HClO} \left(\mathrm{aq}\right)$ solution with a $\mathrm{pH}=3.61$.

Calculate the concentration of ${\mathrm{H}}^{+} \left(\mathrm{aq}\right)$ in a $\mathrm{HClO} \left(\mathrm{aq}\right)$ solution with a $\mathrm{pH}=3.61$.

Which solution has a pH of 9?

A.  1.0 × 10⁻⁹ mol dm⁻³ $\text{HCl}$ (aq)

B.  1.0 × 10⁻⁵ mol dm⁻³ $\text{KOH}$ (aq)

C.  1.0 × 10⁻⁹ mol dm⁻³ $\text{KOH}$ (aq)

D.  1.0 × 10⁻⁵ mol dm⁻³ $\text{HCl}$ (aq)

Saturated calcium hydroxide solution is used to test for carbon dioxide. Calculate the pH of a 2.33 × 10⁻²mol dm⁻³ solution of calcium hydroxide, a strong base.

Saturated calcium hydroxide solution is used to test for carbon dioxide. Calculate the pH of a 2.33 × 10⁻²mol dm⁻³ solution of calcium hydroxide, a strong base.

Saturated calcium hydroxide solution is used to test for carbon dioxide. Calculate the pH of a 2.33 × 10⁻²mol dm⁻³ solution of calcium hydroxide, a strong base.

Saturated calcium hydroxide solution is used to test for carbon dioxide. Calculate the pH of a 2.33 × 10⁻²mol dm⁻³ solution of calcium hydroxide, a strong base.

What is the pH of 0.01 mol dm⁻³ KOH (aq)?

A.  1.0

B.  2.0

C.  12.0

D.  13.0

Which of the 0.001 mol dm⁻³ solutions is most likely to have a pH of 11.3?

A.  Ca(OH)₂(aq)

B.  H₃PO₄(aq)

C.  NaOH (aq)

D.  NH₄OH (aq)

Calculate the concentration of hydroxide ions in an ammonia solution with pH = 9.3. Use sections 1 and 2 of the data booklet.

Calculate the concentration of hydroxide ions in an ammonia solution with pH = 9.3. Use sections 1 and 2 of the data booklet.

Calculate the concentration of hydroxide ions in an ammonia solution with pH = 9.3. Use sections 1 and 2 of the data booklet.

Calculate the concentration of hydroxide ions in an ammonia solution with pH = 9.3. Use sections 1 and 2 of the data booklet.

Calculate the pH of an ammonium nitrate solution with [H₃O⁺] = 1.07× 10⁻⁵ mol dm⁻³. Use section 1 of the data booklet.

Calculate the pH of an ammonium nitrate solution with [H₃O⁺] = 1.07× 10⁻⁵ mol dm⁻³. Use section 1 of the data booklet.

Calculate the pH of an ammonium nitrate solution with [H₃O⁺] = 1.07× 10⁻⁵ mol dm⁻³. Use section 1 of the data booklet.

Calculate the pH of an ammonium nitrate solution with [H₃O⁺] = 1.07× 10⁻⁵ mol dm⁻³. Use section 1 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.

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

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.

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.

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.

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.

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

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)

State the equation for the reaction of each substance with water.

State the equation for the reaction of each substance with water.

Outline why ethanoic acid is classified as a weak acid.

Distinguish between a weak and strong acid.

Weak acid: 

Strong acid: 

Outline why ethanoic acid is classified as a weak acid.

Distinguish between a weak and strong acid.

Weak acid: 

Strong acid:

The dissociation of citric acid is an endothermic process. State the effect on the hydrogen ion concentration, [H⁺], and on K_a, of increasing the temperature.

Identify the compound responsible for the acidity of gastric juice, and state whether it is a strong or weak acid.

The dissociation of citric acid is an endothermic process. State the effect on the hydrogen ion concentration, [H⁺], and on the equilibrium constant, of increasing the temperature.

Which of these acids has the weakest conjugate base?

A.  $\mathrm{HCl}$

B.  ${\mathrm{CH}}_3\mathrm{COOH}$

C.  ${\mathrm{NH}}_4\mathrm{Cl}$

D.  ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COOH}$

Saturated aqueous hydrogen sulfide has a concentration of 0.10 mol dm⁻³ and a pH of 4.0. Demonstrate whether it is a strong or weak acid.

What is the strongest acid in the equation below?

H₃AsO₄ + H₂O $\rightleftharpoons$ H₂AsO₄⁻ + H₃O⁺      K_c = 4.5 × 10⁻⁴

A.  H₃AsO₄

B.  H₂O

C.  H₂AsO₄⁻

D.  H₃O⁺

20 cm³ of 1 mol dm⁻³ sulfuric acid was added dropwise to 20 cm³ of 1 mol dm⁻³ barium hydroxide producing a precipitate of barium sulfate.

H₂SO₄(aq) + Ba(OH)₂(aq) → 2H₂O (l) + BaSO₄(s)

Which graph represents a plot of conductivity against volume of acid added?

Which of these changes would shift the equilibrium to the right?

[Co(H₂O)₆]²⁺ (aq) + 4Cl⁻ (aq) $\rightleftharpoons$ [CoCl₄]²⁻ (aq) + 6H₂O (l)

I.   Addition of 0.01 M HCl
II.  Addition of concentrated HCl
III. Evaporation of water

A.  I and II only

B.  I and III only

C.  II and III only

D.  I, II and III

Outline why ethanoic acid is classified as a weak acid.

Outline why ethanoic acid is classified as a weak acid.

Distinguish between a weak and strong acid.

Weak acid: 

Strong acid: 

Distinguish between a weak and strong acid.

Weak acid: 

Strong acid: 

Outline why ethanoic acid is classified as a weak acid.

Outline why ethanoic acid is classified as a weak acid.

Distinguish between a weak and strong acid.

Weak acid: 

Strong acid:

Distinguish between a weak and strong acid.

Weak acid: 

Strong acid:

The dissociation of citric acid is an endothermic process. State the effect on the hydrogen ion concentration, [H⁺], and on K_a, of increasing the temperature.

The dissociation of citric acid is an endothermic process. State the effect on the hydrogen ion concentration, [H⁺], and on K_a, of increasing the temperature.

Identify the compound responsible for the acidity of gastric juice, and state whether it is a strong or weak acid.

Identify the compound responsible for the acidity of gastric juice, and state whether it is a strong or weak acid.

The dissociation of citric acid is an endothermic process. State the effect on the hydrogen ion concentration, [H⁺], and on the equilibrium constant, of increasing the temperature.

The dissociation of citric acid is an endothermic process. State the effect on the hydrogen ion concentration, [H⁺], and on the equilibrium constant, of increasing the temperature.

Which of these acids has the weakest conjugate base?

A.  $\mathrm{HCl}$

B.  ${\mathrm{CH}}_3\mathrm{COOH}$

C.  ${\mathrm{NH}}_4\mathrm{Cl}$

D.  ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COOH}$

Saturated aqueous hydrogen sulfide has a concentration of 0.10 mol dm⁻³ and a pH of 4.0. Demonstrate whether it is a strong or weak acid.

Saturated aqueous hydrogen sulfide has a concentration of 0.10 mol dm⁻³ and a pH of 4.0. Demonstrate whether it is a strong or weak acid.

What is the strongest acid in the equation below?

H₃AsO₄ + H₂O $\rightleftharpoons$ H₂AsO₄⁻ + H₃O⁺      K_c = 4.5 × 10⁻⁴

A.  H₃AsO₄

B.  H₂O

C.  H₂AsO₄⁻

D.  H₃O⁺

20 cm³ of 1 mol dm⁻³ sulfuric acid was added dropwise to 20 cm³ of 1 mol dm⁻³ barium hydroxide producing a precipitate of barium sulfate.

H₂SO₄(aq) + Ba(OH)₂(aq) → 2H₂O (l) + BaSO₄(s)

Which graph represents a plot of conductivity against volume of acid added?

Which of these changes would shift the equilibrium to the right?

[Co(H₂O)₆]²⁺ (aq) + 4Cl⁻ (aq) $\rightleftharpoons$ [CoCl₄]²⁻ (aq) + 6H₂O (l)

I.   Addition of 0.01 M HCl
II.  Addition of concentrated HCl
III. Evaporation of water

A.  I and II only

B.  I and III only

C.  II and III only

D.  I, II and III

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.

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

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

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

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)

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.

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.

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.

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.

What is the major reason why the pH of unpolluted rain is less than 7?

A. methane

B. carbon dioxide

C. nitrogen oxides

D. sulfur dioxide

What is the major reason why the pH of unpolluted rain is less than 7?

A. methane

B. carbon dioxide

C. nitrogen oxides

D. sulfur dioxide

Which of these oxides contribute to acid deposition?

I.  ${\mathrm{SO}}_2$
II.  ${\mathrm{NO}}_2$
III.  ${\mathrm{CO}}_2$

A.  I and II only

B.  I and III only

C.  II and III only

D.  I, II and III

Outline how one calcium compound in the lime cycle can reduce a problem caused by acid deposition.

Outline how one calcium compound in the lime cycle can reduce a problem caused by acid deposition.

State the product formed from the reaction of SO₃ with water.

Write an equation that shows how sulfur dioxide can produce acid rain.

Write an equation that shows how sulfur dioxide can produce acid rain.

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

What is the major reason why the pH of unpolluted rain is less than 7?

A. methane

B. carbon dioxide

C. nitrogen oxides

D. sulfur dioxide

What is the major reason why the pH of unpolluted rain is less than 7?

A. methane

B. carbon dioxide

C. nitrogen oxides

D. sulfur dioxide

Which of these oxides contribute to acid deposition?

I.  ${\mathrm{SO}}_2$
II.  ${\mathrm{NO}}_2$
III.  ${\mathrm{CO}}_2$

A.  I and II only

B.  I and III only

C.  II and III only

D.  I, II and III

Outline how one calcium compound in the lime cycle can reduce a problem caused by acid deposition.

Outline how one calcium compound in the lime cycle can reduce a problem caused by acid deposition.

Outline how one calcium compound in the lime cycle can reduce a problem caused by acid deposition.

Outline how one calcium compound in the lime cycle can reduce a problem caused by acid deposition.

State the product formed from the reaction of SO₃ with water.

State the product formed from the reaction of SO₃ with water.

Write an equation that shows how sulfur dioxide can produce acid rain.

Write an equation that shows how sulfur dioxide can produce acid rain.

Write an equation that shows how sulfur dioxide can produce acid rain.

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

Write an equation that shows how sulfur dioxide can produce acid rain.

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

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.

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.

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.

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.