Reactivity series test answers and mark scheme for GCSE chemistry (free PDF download)

Question 1 Order of reactivity (2 marks)

Marking: 2 marks for all four correct; 1 mark if only one pair is swapped.

Question 2 Zinc and copper sulfate (3 marks)

1. The blue colour fades and a brown solid forms on the zinc.
2. Zn + Cu²⁺ → Zn²⁺ + Cu.
3. Copper is less reactive than zinc, so it cannot displace it.

Marking: 1 mark each; allow state symbols.

Question 3 Redox in the furnace (3 marks)

1. Fe₂O₃ is reduced because it loses oxygen.
2. CO is oxidised because it gains oxygen.
3. The reducing agent is carbon monoxide.

Marking: 1 mark each.

Question 4 Methods of extraction (2 marks)

1. Aluminium is more reactive than carbon, so carbon cannot remove its oxygen.
2. Gold is very unreactive, so it does not form compounds easily.

Marking: 1 mark each.

Question 5 Iron from iron oxide (3 marks)

1. 2 × 56 + 3 × 16 = 160 g/mol.
2. 4800 ÷ 160 = 30.0 mol.
3. n(Fe) = 60.0 mol; m = 60.0 × 56 = 3360 g = 3.36 kg.

Marking: 1 mark each; allow error carried forward.

Question 6 Interpreting temperature rises (3 marks)

1. Metal A (largest rise).
2. Metal D (no reaction).
3. E lies between C (20 °C) and B (14 °C): A > C > E > B > D.

Marking: 1 mark each.

Question 7 Galvanising (2 marks)

1. Zinc is more reactive than iron, so it loses electrons and corrodes in preference to the iron. This is called sacrificial protection and it works even where the iron is exposed.

Marking: 1 mark for zinc more reactive; 1 mark for corroding instead of iron.

Question 8 Recycling aluminium (2 marks)

Marking: 1 mark for each valid advantage.