Question

A solution react with crushed egg shell which produce a gas which turn lime water milky

Answer 1

in this case the carbon dioxide gas takes place

Answer 2

Question :

A solution produces a gas by reacting with egg shells, which turns lime water to milky.

ANSWER :

Hydrogen chloride

Lime water turns milky and hence the gas is carbon-dioxide.

We already know that egg shells contain calcium carbonate .

Hence the only thing that can displace is HCl .

Thus the answer is HCl as only an acid can perform the above reaction and displace the calcium carbonate to liberate an acidic gas.