Bright Tutorials Bright Tutorials
ICSE Class 10 Chemistry Question 19 of 23

Solved 2025 Specimen Paper ICSE Class 10 Chemistry — Question 18

Back to all questions
18
Question

Question 7(ii)

Rohit has solution X, Y and Z that has pH 2, 7 and 13 respectively.
Which solution:

(a) will liberate sulphur dioxide gas when heated with sodium sulphite

(b) will liberate ammonia gas when reacted with ammonium chloride

(c) will not have any effect on litmus paper?

Answer

(a) X
Reason — Sodium sulphite can react with acids to liberate sulphur dioxide gas. So, the solution X with pH 2 (acidic) will react with sodium sulphite to liberate sulphur dioxide gas.
Na2SO3 + 2H- ⟶ SO2 + H2O + 2Na+

(b) Z
Reason — Ammonium chloride is a salt that, in the presence of a base, will release ammonia gas. Therefore, a basic solution (with a high pH) will react with ammonium chloride to liberate ammonia gas. Thus, the solution Z with pH 13 (basic) will liberate ammonia gas when reacted with ammonium chloride.
NH4Cl + OH- ⟶ NH3 + H2O + Cl-

(c) Y
Reason — The solution Y with pH 7 will not have any effect on litmus paper as it is neither acidic nor basic.