Question

What happens when zinc granules are treated with a dilute solution of H₂SO₄, HCl, HNO₃, NaCl and NaOH, also write the chemical equations if a reaction occurs.

Answer 1

The reaction of Zn granules with 

(a) Dilute H₂SO₄ 

Zn(s) + H₂SO₂(aq) → ZnSO₄ (aq) + H₂(g) 

(b) Dilute HCl 

Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g) 

(c) Dilute HNO3 

Reaction with dilute HNO₃ is different as compared to other acids because nitric acid is an oxidising agent and it oxidises H₂ gas evolved to H₂O. 

4Zn(s) + 10HNO₃(aq) → 4Zn(NO₃)₂ (aq) + 5H₂O(l) + N₂O(g) 

(d) NaCl solution 

Zn(s) + NaCl (aq) → No reaction 

(e) NaOH solution 

Zn(s) + 2NaOH (aq) → Na₂ZnO₂ (aq) + H₂ (g)