When benzyl chloride is treated with ethanolic $KCN$,the major product formed is

The reduction of chloroform with $Zn$ and $HCl$ (alc.) gives ..........

The relative reactivity of the following halides toward $S_{N}2$ reaction follows the order:
$(P)$ $CH_2=CH-Cl$
$(Q)$ $CH_3-CH_2-Cl$
$(R)$ $CH_3-O-CH_2-CH_2-Cl$
$(S)$ $C_6H_5-CH_2-Cl$

Which of the following is an example of $S_N2$ reaction?

Match the following reactions with their mechanisms:
$(A)$ $CH_3CH_2CH_2I \xrightarrow{aq. KOH}$
$(B)$ $(CH_3)_3CCl \xrightarrow{H_2O}$
$(I)$ $S_N1$
$(II)$ $E_2$
$(III)$ $S_N2$
$(IV)$ $E_1$

The major product obtained in the given reaction is: