When propyne reacts with aqueous $H_2SO_4$ in the presence of $HgSO_4$,the major product is

The major product $(A)$ is:

Identify the structures of $P$ and $Q$ in the following reaction sequence:

When $CH_3CH_2CH_2CHCl_2$ is treated with $2 \ g$ equivalent of $NaNH_2$,the product formed is:

Which of the following reagents is most suitable to distinguish compound $(3)$ from the others?
$(1) \ CH_3-C \equiv C-CH_3$
$(2) \ CH_3CH_2CH_2CH_3$
$(3) \ CH_3CH_2C \equiv CH$
$(4) \ CH_3CH=CH_2$

$CH_3-C(Br)_2-C(Br)_2-CH_3$ $\xrightarrow{x NaNH_2}$ $\xrightarrow{y CH_3I} CH_3-C \equiv C-C \equiv C-CH_3$
$x$ and $y$ moles are consumed. The value of $x + y$ is: