Lesson 3.1.12.3

3.1.12.3 The ionic product of water, Kw Quiz: AQA Chemistry, Unit 1

20 questions

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Lesson 3.1.12.3, The ionic product of water, Kw: 20 multiple choice questions for the AQA Chemistry (7405), Unit 1: Physical chemistry, written with Revision Ninja.

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The 20 questions

  1. What is the ionic product of water, Kw, in terms of the ion concentrations?

    • Kw = [H^+] + [OH^-]
    • Kw = [H^+][OH^-]
    • Kw = [H2O]/[H^+][OH^-]
    • Kw = [H^+]/[OH^-]

  2. What process occurs to a very small extent in pure water?

    • Covalent bonding
    • Thermal decomposition
    • Self-ionisation
    • Complete dissociation

  3. At 298 K, Kw = 1.0 x 10^-14 mol^2 dm^-6. What is [H^+] in pure water?

    • 1.0 x 10^-2 mol dm^-3
    • 1.0 x 10^-12 mol dm^-3
    • 1.0 x 10^-14 mol dm^-3
    • 1.0 x 10^-7 mol dm^-3

  4. What is the pH of a 0.010 mol dm^-3 solution of sodium hydroxide, a strong base, at 298 K?

    • 7.00
    • 10.00
    • 2.00
    • 12.00

  5. A solution of a strong base has [OH^-] = 0.10 mol dm^-3 at 298 K. What is its pH?

    • 13.00
    • 0.10
    • 7.00
    • 1.00

  6. How does the value of Kw change as the temperature of water increases?

    • Remains constant
    • Increases
    • Decreases
    • Fluctuates randomly

  7. Which condition defines pure water as neutral at any temperature?

    • Kw equals 1.0x10^-14
    • [H+] equals [OH-]
    • pH equals 7.0
    • [H+] equals 1.0

  8. What is the approximate value of [OH^-] in a solution of pH 3 at 298 K?

    • 1.0 x 10^-7 mol dm^-3
    • 1.0 x 10^-14 mol dm^-3
    • 1.0 x 10^-3 mol dm^-3
    • 1.0 x 10^-11 mol dm^-3

  9. A solution of a strong base has pH 11.0 at 298 K. What is [OH^-] in mol dm^-3?

    • 1.0 x 10^-11
    • 1.0 x 10^-3
    • 1.0 x 10^-1
    • 1.0 x 10^-14

  10. What is the pH of 0.0050 mol dm^-3 potassium hydroxide, a strong base, at 298 K?

    • 12.30
    • 11.70
    • 7.00
    • 2.30

  11. Which mathematical expression defines the ionic product of water, Kw?

    • -log10[H+]
    • [H+][OH-]
    • [H+] + [OH-]
    • [H+]/[OH-]

  12. A solution of pH 9.0 is at 298 K. What is its [OH^-]?

    • 1.0 x 10^-3 mol dm^-3
    • 1.0 x 10^-9 mol dm^-3
    • 1.0 x 10^-5 mol dm^-3
    • 1.0 x 10^-14 mol dm^-3

  13. What is the hydrogen ion concentration in a neutral solution at 298 K?

    • 1.0 x 10^-14 mol dm^-3
    • 7.0 x 10^-7 mol dm^-3
    • 1.0 x 10^-1 mol dm^-3
    • 1.0 x 10^-7 mol dm^-3

  14. Which expression gives the pH of a strong base when its hydroxide concentration is known?

    • pH = -log10[OH^-] at 298 K
    • pH = log10[OH^-] - 14 at 298 K
    • pH = 14 - [OH^-] at 298 K
    • pH = 14 + log10[OH^-] at 298 K

  15. A solution has [OH^-] = 1.0 x 10^-4 mol dm^-3 at 298 K. What is its pH?

    • 10.00
    • 4.00
    • 7.00
    • 14.00

  16. At 298 K, Kw = 1.0 x 10^-14. In a solution with [H^+] = 1.0 x 10^-5 mol dm^-3, what is [OH^-]?

    • 1.0 x 10^-9 mol dm^-3
    • 1.0 x 10^-14 mol dm^-3
    • 1.0 x 10^-5 mol dm^-3
    • 1.0 x 10^-19 mol dm^-3

  17. What are the units of the ionic product of water, Kw?

    • mol dm-3
    • mol2 dm-3
    • mol2 dm-6
    • mol-2 dm6

  18. At 373 K, Kw is greater than at 298 K. What is the pH of pure water at 373 K?

    • Less than 7
    • Greater than 7
    • Zero
    • Exactly 7

  19. At 298 K, how is a solution with a pH of 7.5 classified?

    • Amphoteric
    • Acidic
    • Alkaline
    • Neutral

  20. What is the pH of a 0.0010 mol dm^-3 solution of sodium hydroxide at 298 K?

    • 14.00
    • 3.00
    • 7.00
    • 11.00

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