Question

Making use only of substances chosen from those given below:

Dilute sulphuric acid Zinc Lead

sodium carbonate sodium sulphite calcium carbonate

Give the equations for the reactions by which you could obtain:
(i) hydrogen
(ii) sulphur dioxide
(iii) carbon dioxide
(iv) zinc carbonate (two steps required).

Answer 1

(i) Zinc reacts with dilute sulphuric acid to evolve hydrogen.

Zn + H₂SO₄ → ZnSO₄ + H₂↑

(ii) Sodium sulphite reacts with dilute sulphuric acid to give sulphur dioxide.

Na₂SO₃ + H₂SO₄ → Na₂SO₄ + H₂O + SO₂↑

(iii) Sodium carbonate reacts with dilute sulphuric acid to give carbon dioxide.

Na₂CO₃ + H₂SO₄ → Na₂SO₄ + H₂O + CO₂↑

(iv) Zinc reacts with dilute sulphuric acid to form zinc sulphate, which on reaction with sodium carbonate forms zinc carbonate.

Zn + H₂SO₄ → ZnSO₄ + H₂↑

ZnSO₄ + Na₂CO₃ → ZnCO₃ + Na₂SO₄