GCSE Chemistry (AQA) chapter 3: Quantitative chemistry MCQs with answers

By Team Megalecture · Updated 4 Nov 2026

38 exam-style questions on Quantitative chemistry, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.

38 questions · 4 topics · 10 per test

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What chapter 3 covers

Ten Quantitative chemistry questions with answers

Try each one, then open the answer. These ten stay the same; the test draws new ones every time.

1. What is the relative formula mass of calcium carbonate, CaCO3?

  1. A
    68
  2. B
    84
  3. C
    100
  4. D
    116
Show answer

Answer: C. Mr = 40 + 12 + (3 × 16) = 100. 68 comes from counting only one oxygen.

2. 5.6 g of iron reacts exactly with 10.65 g of chlorine, Cl2. Which balanced equation fits these masses?

  1. A
    2Fe + Cl2 → 2FeCl
  2. B
    3Fe + 2Cl2 → Fe3Cl4
  3. C
    Fe + Cl2 → FeCl2
  4. D
    2Fe + 3Cl2 → 2FeCl3
Show answer

Answer: D. Fe: 5.6 ÷ 56 = 0.10 mol. Cl2: 10.65 ÷ 71 = 0.15 mol. The ratio 0.10 : 0.15 = 2 : 3, giving 2Fe + 3Cl2 → 2FeCl3.

3. What mass of sodium hydroxide is needed to make 250 cm3 of a 0.20 mol/dm3 solution?

  1. A
    0.050 g
  2. B
    2.0 g
  3. C
    8.0 g
  4. D
    32 g
Show answer

Answer: B. Moles = 0.20 × 0.250 = 0.050 mol. Mass = 0.050 × 40 = 2.0 g (Mr of NaOH = 40). 8.0 g ignores the volume (0.20 × 40), and 0.050 is the number of moles, not the mass.

4. CaCO3 + 2HCl → CaCl2 + H2O + CO2. What volume of carbon dioxide at room temperature and pressure forms when 10 g of calcium carbonate reacts with excess acid?

  1. A
    24 dm3
  2. B
    4.8 dm3
  3. C
    2.4 dm3
  4. D
    1.2 dm3
Show answer

Answer: C. 10 ÷ 100 = 0.10 mol CaCO3, giving 0.10 mol CO2. Volume = 0.10 × 24 = 2.4 dm3. 4.8 dm3 wrongly uses the 2 from 2HCl.

5. Hydrogen is made by CH4 + H2O → CO + 3H2. What is the atom economy for hydrogen?

  1. A
    82.4%
  2. B
    21.4%
  3. C
    17.6%
  4. D
    5.9%
Show answer

Answer: C. Total Mr of reactants = 16 + 18 = 34. Useful product 3H2 = 6. Atom economy = 6 ÷ 34 × 100 = 17.6%. 5.9% uses only one H2.

6. CuO + H2 → Cu + H2O. What is the theoretical mass of copper made from 7.95 g of copper(II) oxide?

  1. A
    12.7 g
  2. B
    7.95 g
  3. C
    6.35 g
  4. D
    3.18 g
Show answer

Answer: C. Mr CuO = 63.5 + 16 = 79.5, so 7.95 ÷ 79.5 = 0.100 mol. This gives 0.100 mol Cu: 0.100 × 63.5 = 6.35 g.

7. A reaction has a theoretical yield of 25 g and a percentage yield of 60%. What mass of product was obtained?

  1. A
    10 g
  2. B
    15 g
  3. C
    41.7 g
  4. D
    60 g
Show answer

Answer: B. Actual yield = 60 ÷ 100 × 25 = 15 g. 41.7 g comes from 25 ÷ 0.60, which would be more than the maximum possible.

8. Mg + 2HCl → MgCl2 + H2. 0.10 mol of magnesium is added to 0.10 mol of hydrochloric acid. Which statement is correct?

  1. A
    the metal limits the reaction and 0.10 mol of hydrogen forms
  2. B
    the acid limits the reaction and 0.10 mol of hydrogen forms
  3. C
    both are used up and 0.10 mol of hydrogen forms
  4. D
    the acid limits the reaction and 0.050 mol of hydrogen forms
Show answer

Answer: D. 0.10 mol Mg would need 0.20 mol HCl, but only 0.10 mol is present, so HCl runs out first. 0.10 mol HCl gives 0.10 ÷ 2 = 0.050 mol H2.

9. How many atoms are in 1.0 mol of water, H2O? (Avogadro constant = 6.02 × 1023 per mole)

  1. A
    6.02 × 1023
  2. B
    1.20 × 1024
  3. C
    1.81 × 1024
  4. D
    1.08 × 1025
Show answer

Answer: C. 1 mol of molecules is 6.02 × 1023 molecules, each with 3 atoms: 3 × 6.02 × 1023 = 1.81 × 1024.

10. 25.0 cm3 of sodium hydroxide solution is neutralised by 20.0 cm3 of 0.10 mol/dm3 hydrochloric acid. NaOH + HCl → NaCl + H2O. What is the concentration of the sodium hydroxide?

  1. A
    0.125 mol/dm3
  2. B
    0.10 mol/dm3
  3. C
    0.080 mol/dm3
  4. D
    0.0020 mol/dm3
Show answer

Answer: C. Moles HCl = 0.10 × 0.0200 = 0.0020 mol = moles NaOH (1:1). Concentration = 0.0020 ÷ 0.0250 = 0.080 mol/dm3. 0.125 uses the volumes the wrong way round.

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How many Quantitative chemistry MCQs are there?

38, each with the answer and a short explanation, across 4 topics: 4.3.1 Conservation of mass and relative formula mass, 4.3.2 Moles, reacting masses and limiting reactants (HT), 4.3.3 Yield and atom economy, 4.3.2.5, 4.3.4-4.3.5 Concentrations of solutions and volumes of gases. Every chapter test draws ten of them, so you can take it many times.

Is the GCSE Chemistry (AQA) chapter 3 test free?

Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.

How is the chapter test marked?

The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.

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