Alcoholic solution of $KOH$ is used for

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

Which among the following compounds undergoes $SN^2$ reaction most rapidly?

The reaction $RCl + NaI \xrightarrow{\text{Acetone}} R-I + NaCl$ is known as:

For $(i) \, I^{-}, \, (ii) \, Cl^{-}, \, (iii) \, Br^{-}$,the increasing order of nucleophilicity would be

The reaction of $1$-chlorobutane with alcoholic $KOH$ yields .....