Question

(a) Name the gas evolved when dilute hydrochloric acid is added to:
(i) Zinc metal
(ii) Calcium carbonate
(iii) Sodium sulphite
(iv) Lead (II) sulphide
(v) Magnesium bicarbonate
(vi) Potassium bisulphite
(b) Give a balanced equation for each of the above reaction.

Answer 1

(a)
(i) when dilute hydrochloric acid is added to Zinc metal, zinc chloride and hydrogen gas is formed
(ii) when dilute hydrochloric acid is added to Calcium carbonate, calcium chloride, water and carbon dioxide gas are formed.
(iii) when dilute hydrochloric acid is added to Sodium sulphite, sodium chloride, water and sulphur dioxide gas are formed.
(iv) when dilute hydrochloric acid is added to Lead (II) sulphide, lead chloride and hydrogen sulphide gas are formed.
(v) when dilute hydrochloric acid is added to Magnesium bicarbonate, magnesium chloride, water and carbon dioxide gas is formed.
(vi) when dilute hydrochloric acid is added to Potassium bisulphite, potassium chloride, water and sulphur dioxide gas are formed.
(b)

(i) Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)
Zinc Hydrogen gas
(ii) CaCO₃(s) + 2HCl(aq) →​ CaCl₂(aq) + H₂O(l) + CO₂ (g)
Calcium Carbon dioxide gas
carbonate
(iii) Na₂SO₃(aq) + 2HCl(aq) →​​ 2NaCl(aq) + SO₂(g) + H₂O(l)
Sodium Sulphur
sulphite dioxide
gas
(iv) PbS(s) + 2HCl(aq) →​ PbCl₂(s) + H₂S(g)
Lead (II) Hydrogen
sulphide sulphide gas
(v) Mg(HCO₃)₂(aq) + 2HCl(aq) →​ MgCl₂(aq) + 2H₂O(l) + 2CO₂(g)
Magnesium Carbondioxide
bicarbonate gas
(vi) KHSO₃(aq) + HCl(aq) → KCl(aq) + H₂O(l) + SO₂(g)
Potassium Sulphur dioxide gas
bisulphite