Question

When a gas ‘X’ is passed through lime water, the lime water turns milky due to formation of a substance ‘Y’. Identify X and Y.

• A. Can not be determined
• B. $X=\mathrm{CO};Y={\mathrm{CaCO}}_3$
• C. $X={\mathrm{CO}}_2;Y={\mathrm{CaCO}}_3$
• D. $X=O_2;Y={\mathrm{Na}}_2{\mathrm{CO}}_3$

Answer 1

The correct option is C $X={\mathrm{CO}}_2;Y={\mathrm{CaCO}}_3$

$Ca{\left(OH\right)}_2+C{O}_2\to {\mathrm{CaCO}}_3+H_{2}O$

The milky appearance is due to the formation of calcium carbonate, that is,$CaC{O}_3$.