An unknown compound $(A)$ (molar mass $= 180$) on acylation gives a product (molar mass $= 390$). Find the number of hydroxyl group present in compound $(A)$.

The product of the reaction is:

If $(\pm)$ $2$-methylbutanoic acid is esterified by reaction with $(\pm)$ $2$-butanol,how many optically active compounds will be present in the final equilibrium reaction mixture?

An organic compound having molecular formula $C_2H_6O$ undergoes oxidation with $K_2Cr_2O_7 / H_2SO_4$ to produce $X$ which contains $40\,\%$ carbon,$6.7\,\%$ hydrogen and $53.3\,\%$ oxygen. The molecular formula of the compound $X$ is

Select the reaction with an incorrect name.

Identify $Z$ in the following reaction sequence:
$CH_3COONH_4$ $\xrightarrow{\Delta} X$ $\xrightarrow{P_2O_5} Y$ $\xrightarrow{H_2O/H^+} Z$