Question

A solution reacts with crushed egg shells to give a gas that turns lime water milky. The solution must be sodium chloride or HCL. Explain by giving chemical reaction.

Answer 1

Egg shells contains calcium carbonate, which on reaction with HCl liberates CO2 gas which turn lime water to milky.

CaCO3 + 2HCl → CaCl2 + H2O + CO2

Answer 2

ANSWER :

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.

Reaction :

CaCO₃ + 2HCl => CaCl₂ + H₂O + CO₂

CO₂ + Ca(OH)₂=>CaCO₃ + H₂O ( limewater turns milky )