The major product of the following reaction is: $CH_3-CH_2-CH(Br)-CH_2-Br \xrightarrow[(ii) NaNH_2 \text{ in liq. } NH_3]{(i) KOH \text{ alc.}}$

The reaction of acetylene with acetic acid in the presence of $Hg^{2+}$ at room temperature yields ....

$CH_3-C \equiv C-CH_3 \xrightarrow{\text{Cold } KMnO_4} (A)$
Product $(A)$ is:

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

Predict the product of the following reaction sequence:
$HC \equiv CH$ $\xrightarrow[\begin{smallmatrix} (2) \text{ excess } I-CH_2-(CH_2)_2-CH_3 \\ (3) \text{ } H^{\oplus} \end{smallmatrix}]{(1) \text{ excess } NaNH_2}$

Identify the alkyne in the following sequence of reactions: