Chemistry · May / June 2022 · Paper 11 · Question 24

The table gives some information about four redox reactions. Which row gives correct information about what is oxidised and the evidence that this is oxidation?

1. ACuO(s) + C(s) ⇌ CO(g) + Cu(s) | copper | copper oxide has given oxygen to carbon
2. BNa(s) + ½Cl₂(g) ⇌ NaCl(s) | sodium | sodium has lost an electron
3. CN₂(g) + 3H₂(g) ⇌ 2NH₃(g) | nitrogen | nitrogen has gained hydrogen
4. DZn(NO₃)₂(aq) + Mg(s) ⇌ Mg(NO₃)₂(aq) + Zn(s) | zinc | zinc has gained two electrons

As printed in the paper