GCSE Chemistry quiz: 24 questions

Choose one answer for each question, then press Check my answers under the set. You will see a short explanation for every question. Use a calculator where a question says Calculation. Relative atomic masses are given in the questions that need them.

Set 1: structure, bonding, quantitative chemistry, chemical and energy changes

1. An atom of sodium is written as ²³₁₁Na (mass number 23, atomic number 11). How many neutrons does it contain? A. 11 B. 12 C. 23 D. 34

2. Why does reactivity increase going down Group 1? A. The nucleus becomes more positive, holding the outer electron more tightly B. The outer electron is further from the nucleus, so it is lost more easily C. Atoms gain extra outer electrons D. Atoms get smaller

3. Which is the formula of the ionic compound formed by calcium (Ca²⁺) and chloride (Cl⁻) ions? A. CaCl B. Ca₂Cl C. CaCl₂ D. Ca₂Cl₂

4. Calculation. What is the relative formula mass of calcium carbonate, CaCO₃? (Aᵣ: Ca = 40, C = 12, O = 16) A. 68 B. 84 C. 100 D. 116

5. Calculation. How many moles are there in 12 g of magnesium? (Aᵣ of Mg = 24) A. 0.5 mol B. 2 mol C. 12 mol D. 288 mol

6. Calculation. 2Mg + O₂ → 2MgO. What mass of magnesium oxide forms from 4.8 g of magnesium? (Aᵣ: Mg = 24, O = 16) A. 4.8 g B. 6.4 g C. 8.0 g D. 9.6 g

7. Which set of numbers balances Al + O₂ → Al₂O₃, in the order Al, O₂, Al₂O₃? A. 2, 3, 1 B. 4, 3, 2 C. 2, 2, 1 D. 3, 2, 3

8. What are the products when dilute hydrochloric acid reacts with sodium carbonate? A. Sodium chloride, water and carbon dioxide B. Sodium chloride and hydrogen C. Sodium hydroxide and chlorine D. Sodium chloride and water only

9. In the electrolysis of molten lead bromide, what forms at the negative electrode? A. Bromine B. Lead C. Oxygen D. Hydrogen

10. Magnesium is added to copper sulfate solution. What happens? A. Nothing, because copper is more reactive B. Copper is displaced because magnesium is more reactive C. Magnesium is displaced because it is less reactive D. Hydrogen is produced

11. Calculation. Bond energies: H–H 436, Cl–Cl 243, H–Cl 432 kJ/mol. What is the energy change for H₂ + Cl₂ → 2HCl? A. −185 kJ/mol B. +185 kJ/mol C. −864 kJ/mol D. +679 kJ/mol

12. Calculation. 4.0 g of sodium hydroxide is dissolved to make 500 cm³ of solution. What is the concentration? A. 0.008 g/dm³ B. 2.0 g/dm³ C. 8.0 g/dm³ D. 2000 g/dm³

Set 2: rates, organic chemistry, analysis, atmosphere and resources

1. Why does raising the temperature increase the rate of a reaction? A. Particles collide more often and with more energy B. Activation energy becomes smaller C. Particles become larger D. More particles are created

2. Calculation. A reaction produces 48 cm³ of gas in 40 seconds. What is the mean rate? A. 0.83 cm³/s B. 1.2 cm³/s C. 8 cm³/s D. 1920 cm³/s

3. How does a catalyst speed up a reaction? A. By raising the temperature B. By being used up as a reactant C. By providing a route with lower activation energy D. By increasing the activation energy

4. A reversible reaction reaches dynamic equilibrium in a closed system. What is true? A. The reaction has stopped B. The forward and reverse reactions happen at the same rate C. All reactants have been used up D. Only the forward reaction continues

5. What is the molecular formula of the alkane with six carbon atoms? A. C₆H₁₂ B. C₆H₁₄ C. C₆H₁₆ D. C₆H₈

6. What is seen when an alkene is shaken with bromine water? A. It stays orange B. It turns from orange to colourless C. It turns blue D. A white solid forms

7. In the complete combustion of methane, CH₄ + _O₂ → CO₂ + 2H₂O, how many O₂ molecules are needed? A. 1 B. 2 C. 3 D. 4

8. Calculation. In chromatography a spot moves 3.0 cm and the solvent front moves 7.5 cm. What is the Rf value? A. 0.40 B. 2.5 C. 4.5 D. 0.25

9. Which test shows that a gas is carbon dioxide? A. It relights a glowing splint B. It turns limewater milky C. It bleaches damp litmus paper D. It makes a squeaky pop with a lit splint

10. Which of these is a greenhouse gas? A. Nitrogen B. Argon C. Methane D. Oxygen

11. Which stage in treating fresh water to make it potable removes insoluble solids? A. Filtration B. Distillation C. Electrolysis D. Cracking

12. Calculation. The maximum possible mass of a product is 8.0 g and 6.0 g is collected. What is the percentage yield? A. 25% B. 75% C. 133% D. 48%

For more, read the revision guide, look terms up in the glossary or use the flashcard tool.

Part of the GCSE Chemistry revision set: the revision guide and glossary of key terms.

GCSE Chemistry quiz

Set 1: structure, bonding, quantitative chemistry, chemical and energy changes

Set 2: rates, organic chemistry, analysis, atmosphere and resources

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