The compound $X$ on reaction with $HgSO_4 + H_2SO_4$ gives $Y$ which on oxidation gives acetic acid. $X$ is

In the given reaction,
$Ph-C \equiv C-CH_3 \xrightarrow{H^{+}/Hg^{2+}} A$
the product $A$ is

Identify the alkyne in the following sequence of reactions:

$A$ hydrocarbon with molecular formula $C_6H_6$ decolourises $Br_2$ water and gives a precipitate with ammoniacal $AgNO_3$. The hydrocarbon is:

Given below are two statements:
Statement $I$: One mole of propyne reacts with excess of sodium to liberate half a mole of $H_2$ gas.
Statement $II$: Four $g$ of propyne reacts with $NaNH_2$ to liberate $NH_3$ gas which occupies $224 \ mL$ at $STP$.
In the light of the above statements,choose the most appropriate answer from the options given below:

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 $\text{g mol}^{-1}$: $C:12, H:1$)