8.3 The pH scale

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.  $12.0$

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 $\mathrm{pH}=3.61$.

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.

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.

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

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)

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)

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.

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.)

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

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

A. 1

B. 3

C. 11

D. 13

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

A. 1

B. 3

C. 11

D. 13

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.)

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

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

A. 1

B. 3

C. 11

D. 13

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

A. 1

B. 3

C. 11

D. 13

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.

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

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.

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

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.

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.

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.

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

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

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.

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.

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

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

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

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

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

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

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)

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.

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 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.

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.

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.