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

Arrange the following reactants in increasing order of reactivity towards $S_{N^1}$ solvolysis reaction with methanol.

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 $g \ mol^{-1}$: $H: 1, C: 12, Br: 80$)

Match List-$I$ with List-$II$:

List-$I$	List-$II$
$a$. Benzenediazonium chloride $\xrightarrow{Cu_2Cl_2/HCl}$ Chlorobenzene $+ N_2$	$i$. Wurtz reaction
$b$. Benzenediazonium chloride $\xrightarrow{Cu/HCl}$ Chlorobenzene $+ N_2$	$ii$. Sandmeyer reaction
$c$. $2 CH_3CH_2Cl + 2 Na \xrightarrow{Ether} C_2H_5-C_2H_5 + 2 NaCl$	$iii$. Fittig reaction
$d$. $2 C_6H_5Cl + 2 Na \xrightarrow{Ether} C_6H_5-C_6H_5 + 2 NaCl$	$iv$. Gatterman reaction

Choose the correct answer from the options given below:

Complete the following reactions:
$(1)$ $1$-Chloropropane $\xrightarrow[{KOH}]{{\text{ethanol}}} (B)$ $\xrightarrow[{CCl_4}]{{Br_2}} (C)$
$(2)$ Ethane $\xrightarrow[{hv}]{{Cl_2}} (B)$ $\xrightarrow[{Na, \text{ether}}]{} (C)$

Which of the following cannot undergo nucleophilic substitution under ordinary conditions?