Which of the following is $NOT$ obtained when a mixture of chloroethane and $1-$chloropropane is treated with sodium metal in dry ether?

Predict the major product of the following reaction sequence $:-$

Match the reactions in Column-$I$ with their mechanisms in Column-$II$.

Column-$I$ (Reaction)	Column-$II$ (Mechanism)
$(A)$ $OH^- + CH_3Cl \to HOCH_3 + Cl^-$	$(1)$ $S_N2$ mechanism
$(B)$ $(CH_3)_3CBr + OH^- \to (CH_3)_3COH + Br^-$	$(2)$ $S_E2$ aromatic
$(C)$ $CH_3CH_2Br \xrightarrow[ethanol]{KOH} CH_2 = CH_2$	$(3)$ $S_N1$ mechanism
$(D)$ $C_6H_6 + Br_2 \xrightarrow{Fe} C_6H_5Br + HBr$	$(4)$ $\beta$-elimination (dehydrohalogenation)

Which of the following products can be obtained from the above reaction?

What will be the final product in the given reaction?

Given below are four compounds:
$(a)$ $n$-propyl chloride,
$(b)$ $iso$-propyl chloride,
$(c)$ $sec$-butyl chloride,
$(d)$ $neo$-pentyl chloride.
Percentage of carbon in the one which exhibits optical isomerism is: