$CH \equiv CH$ $\xrightarrow{HCl \text{ (Excess)}} A$ $\xrightarrow{\text{Hydrolysis}, \Delta} B$ $\xrightarrow{\text{Reduction}, Na-Hg / H_2O} C$
Compound $C$ is

Explain the acidic nature of ethyne.

In which of the following cases is the bond length between carbon and nitrogen minimum?

Compound $(X)$ [styrene] is subjected to the following sequence of reactions: $(i)$ $Br_2/CHCl_3$, $(ii)$ $NaNH_2$ (excess), $(iii)$ $CH_3I$, $(iv)$ $H_2, Na/NH_3(l)$, giving Major Product $(Y)$. The molar mass of the major product $(Y)$ formed is . . . . . . $\text{g mol}^{-1}$. (Given molar mass in $\text{g mol}^{-1}$: $C:12, H:1$)

When acetylene is passed through a solution of dilute sulfuric acid containing mercuric sulfate,the number of $\pi$ bonds in the final product obtained is.........

The relation between $(B)$ and $(C)$ is:
$CH_3-C \equiv CH$ $\xrightarrow{NaNH_2}$ $\xrightarrow{CH_3-I} (A)$ $\xrightarrow{Li/liq. NH_3} (B)$
$CH_3-C \equiv CH$ $\xrightarrow{NaNH_2}$ $\xrightarrow{CH_3-I} (A)$ $\xrightarrow[Pd/CaCO_3]{H_2} (C)$