$S_N1$ reactions are generally carried out in which type of solvents?

Which of the following is a polar aprotic solvent?

Identify the alkyl halide that undergoes $SN^2$ reaction most rapidly.

Explain elimination reactions of alkyl halides.
or
Explain dehydrohalogenation ($\beta$-elimination) of alkyl halides.

The major product obtained in the following reaction is $C_2H_5ONa + (CH_3)_3C-Cl \rightarrow$

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