Question

Give reason why lime water finds application for testing both carbon dioxide and carbon monoxide gas individually​

Answer 1

Carbon dioxide does it because it reacts with calcium hydroxide (limewater being a solution of that) to form calcium carbonate, which is insoluble. The net reaction is:

CO22(g) + Ca(OH)22(aq) → CaCO33(s) + H22O(l).

The milkiness is due to the formation of small particles of calcium carbonate.

Carbon monoxide does NOT turn limewater milky, unless it is contaminated with some carbon dioxide.

Answer 2

Carbon dioxide does it because it reacts with calcium hydroxide to form calcium carbonate, which is insoluble. ... The milkiness is due to the formation of small particles of calcium carbonate.