The product $(X)$ is:

Consider the above sequence of reactions. $151 \ g$ of $2-$bromopentane is made to react. The yield of the major product $P$ is $80 \%$ whereas the yield of $Q$ is $100 \%$. The mass of product $Q$ obtained is $........ \ g$. (Given molar mass in $g \ mol^{-1}$: $H: 1, C: 12, Br: 80$)

Identify the major products $(P)$ and $(Q)$ respectively for the given reaction.

Product $(A)$ in this sequence is:

$C_3H_7I$ $(P)$ $\xrightarrow[\text{alc. } KOH]{\Delta}$ $Q$ $\xrightarrow{NBS}$ $R$ $\xrightarrow{KCN}$ $CH_2 = CH - CH_2 - CN$. $P$ can be:

In the following reaction sequence, $X$ and $Z$, respectively, are:
$CH_{3}CH_{2}CH_{2}-OH + PCl_{5} \rightarrow CH_{3}CH_{2}CH_{2}Cl + X + HCl$
$CH_{3}CH_{2}CH_{2}Cl \xrightarrow{alc. KOH, \Delta} Y$
$Y \xrightarrow{HBr, (C_{6}H_{5}CO)_{2}O_{2}} Z$