Lesson 12.2.1

12.2.1 pH of strong acids and bases, and Kw Quiz: Pearson Edexcel Chemistry, Unit 12

20 questions

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Lesson 12.2.1, pH of strong acids and bases, and Kw: 20 multiple choice questions for the Pearson Edexcel Chemistry (9CH0), Unit 12: Acid-base Equilibria, written with Revision Ninja.

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The 20 questions

  1. What is the ionic product of water, Kw, at 298 K?

    • 1.00 x 10^-7 mol2 dm-6
    • 1.00 mol2 dm-6
    • 1.00 x 10^-14 mol2 dm-6
    • 1.00 x 10^7 mol2 dm-6

  2. In pure water at 298 K, what is [H+]?

    • 1.00 x 10^-14 mol dm-3
    • 1.00 x 10^-7 mol dm-3
    • 1.00 x 10^-1 mol dm-3
    • 1.00 mol dm-3

  3. What is the pH of 0.100 mol dm-3 hydrochloric acid, a strong acid?

    • 1.00
    • 0.10
    • 7.00
    • 13.00

  4. What is the pH of 0.0100 mol dm-3 sulfuric acid, which is fully dissociated to give two H+ per molecule?

    • 12.00
    • 1.70
    • 1.00
    • 2.00

  5. What is the pH of 0.0200 mol dm-3 sodium hydroxide, a strong base?

    • 1.70
    • 11.70
    • 2.00
    • 12.30

  6. What is [OH-] in a solution of pH 10.0 at 298 K?

    • 1.0 x 10^-14 mol dm-3
    • 10.0 mol dm-3
    • 1.0 x 10^-4 mol dm-3
    • 1.0 x 10^-10 mol dm-3

  7. Which expression correctly gives the pH of a strong base of concentration c mol dm-3 at 298 K?

    • pH = -log10(c)
    • pH = 14 - log10(c)
    • pH = log10(c) only
    • pH = 14 + log10(c)

  8. A solution of a strong acid is diluted 10 times. Which pH change is expected for a strong acid starting at pH 3.00?

    • pH 2.00
    • pH 3.00 unchanged
    • pH 4.00
    • pH 3.10

  9. Comparing a strong acid and a weak acid after dilution, which statement is correct?

    • Both acids have identical pH values at all dilutions
    • The pH of the weak acid changes less on dilution than the pH of the strong acid
    • The pH of the weak acid changes more because it is less dissociated
    • Dilution makes the weak acid's pH fall more rapidly

  10. Why does a pH of 13.0 correspond to a strong base solution at 298 K?

    • The solution is neutral, because the pH of 13.0 lies close to the neutral pH of 7 on the scale
    • The solution has pKw of 13, which is the value that determines the strength of the base in water
    • [OH-] = 0.10 mol dm-3, showing high hydroxide concentration
    • [H+] = 0.10 mol dm-3, which means the solution has a high concentration of hydrogen ions and is acidic

  11. What is the pH of 0.00100 mol dm-3 hydrochloric acid?

    • 3.00
    • 11.00
    • 0.00100
    • 1.00

  12. Which statement about Kw is correct?

    • Kw decreases with temperature because water dissociates exothermically
    • Kw depends on the concentration of acid added
    • Kw is always 1.00 at any temperature
    • Kw increases with temperature because the dissociation of water is endothermic

  13. What is the pH of 2.00 x 10^-3 mol dm-3 HNO3? (log10 2 = 0.30)

    • 3.30
    • 2.00
    • 2.70
    • 11.30

  14. For a strong acid of pH 2.00, what is the concentration of H+ ions in mol dm-3?

    • 1.0 x 10^-2 mol dm-3
    • 2.0 mol dm-3
    • 0.20 mol dm-3
    • 1.0 x 10^-12 mol dm-3

  15. What is the pH of 0.0500 mol dm-3 calcium hydroxide, Ca(OH)2, a strong base giving two OH- per formula unit? (log10 1.0 = 0)

    • 12.00
    • 13.00
    • 1.30
    • 12.70

  16. Which expression gives [H+] from Kw and [OH-] in a strong base solution?

    • [H+] = Kw / [OH-]
    • [H+] = [OH-] / Kw
    • [H+] = Kw - [OH-]
    • [H+] = Kw x [OH-]

  17. A student adds 1.00 cm3 of 1.00 mol dm-3 HCl to 999 cm3 of water. What is the pH of the solution?

    • 3.00
    • 7.00
    • 1.00
    • 0.00

  18. Which statement about the pH of a strong acid is correct?

    • pH is found from the square root of the acid concentration, which is the standard method for all acids
    • pH is the same as pKa for all strong acids, because both measure how fully the acid dissociates
    • pH is found from -log10 of the hydrogen ion concentration, which equals the acid concentration for a monoprotic acid
    • pH equals the concentration in mol dm-3, so a 0.10 mol dm-3 acid has a pH of 0.10 exactly

  19. What is the pH of 1.0 x 10^-8 mol dm-3 hydrochloric acid, allowing for water's own ionisation?

    • Exactly 14.00, because the solution becomes fully alkaline when the acid is diluted in water
    • Exactly 8.00, because the pH of any dilute acid is always eight units above the value of the acid
    • Exactly 1.00, because the pH is set by the acid concentration alone and water has no effect on it
    • Close to 7, because water also contributes H+

  20. What is the pH of 0.250 mol dm-3 sodium hydroxide? (log10 4 = 0.60)

    • 13.40
    • 0.60
    • 12.00
    • 14.60

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