Lesson 3.1.12.2

3.1.12.2 Definition and determination of pH Quiz: AQA Chemistry, Unit 1

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

In partnership with Revision Ninja

Lesson 3.1.12.2, Definition and determination of pH: 20 multiple choice questions for the AQA Chemistry (7405), Unit 1: Physical chemistry, written with Revision Ninja.

Host it live on the board and students join with a game code on their own devices, or revise alone with Free Play. The answers are revealed in the game.

Host this setFree Play

The 20 questions

  1. What is the definition of pH?

    • pH = -log10[H^+]
    • pH = -[H^+]/10
    • pH = 1/[H^+]
    • pH = log10[H^+]

  2. A solution has [H^+] = 1.0 x 10^-3 mol dm^-3. What is its pH?

    • 3
    • 11
    • 1
    • -3

  3. A solution has pH 2.5. What is [H^+] in mol dm^-3?

    • 1.0 x 10^-2
    • 3.2 x 10^-3
    • 2.5 x 10^-3
    • 2.5 x 10^-2

  4. What is the pH of 0.050 mol dm^-3 hydrochloric acid, a strong acid?

    • 12.70
    • 1.30
    • 2.30
    • 0.05

  5. What is the pH of 0.0025 mol dm^-3 hydrochloric acid?

    • 2.60
    • 2.25
    • 3.00
    • 0.0025

  6. A solution has pH 4.0. What is [H^+] in mol dm^-3?

    • 1.0 x 10^4
    • 1.0 x 10^-4
    • 4.0 x 10^-4
    • 1.0 x 10^-10

  7. A solution has pH 5.2. What is [H^+] in mol dm^-3?

    • 5.2 x 10^-6
    • 7.9 x 10^-6
    • 6.3 x 10^-6
    • 1.6 x 10^-5

  8. If the hydrogen ion concentration of a solution doubles, how does its pH change?

    • Halves in value
    • Increases by 0.30
    • Decreases by 2.00
    • Decreases by 0.30

  9. What is the pH of 0.010 mol dm^-3 nitric acid, a strong acid?

    • 0.010
    • 12.00
    • 1.00
    • 2.00

  10. What is the pH of 0.0010 mol dm^-3 nitric acid?

    • 3.00
    • 0.0010
    • 2.00
    • 4.00

  11. What is the pH of 0.20 mol dm^-3 hydrochloric acid?

    • 13.30
    • 1.30
    • 0.20
    • 0.70

  12. How many times greater is [H^+] in a solution of pH 2 than in a solution of pH 4?

    • 100 times
    • 10 times
    • 1000 times
    • 2 times

  13. Which of these 1.0 mol dm^-3 aqueous solutions has the lowest pH?

    • Sodium hydroxide
    • Ethanoic acid
    • Hydrochloric acid
    • Ammonia

  14. A solution of hydrochloric acid with pH 1.0 is diluted 100 times. What is the approximate new pH?

    • 3.0
    • 0.01
    • 7.0
    • 1.0

  15. What is the pH of 0.25 mol dm^-3 nitric acid, a strong acid?

    • 0.60
    • 1.60
    • 0.40
    • 0.25

  16. What is [H^+] in mol dm^-3 for a solution of pH 5.5?

    • 1.8 x 10^-6
    • 3.2 x 10^-6
    • 3.2 x 10^-5
    • 5.5 x 10^-6

  17. What property of a monoprotic strong acid allows its concentration to equal [H+]?

    • High molar mass
    • High boiling point
    • Complete dissociation
    • Partial dissociation

  18. Why is a logarithmic scale used to express hydrogen ion concentration as pH?

    • Linear scale variation
    • Unknown acid strength
    • Constant temperature changes
    • Wide concentration range

  19. A solution has [H^+] = 2.5 x 10^-4 mol dm^-3. What is its pH to one decimal place?

    • 2.5
    • 3.0
    • 3.6
    • 4.0

  20. When the pH of a solution decreases by 1 unit, how does [H+] change?

    • Halves
    • Decreases tenfold
    • Doubles
    • Increases tenfold

All AQA Chemistry quizzes