What is an alcoholic solution of $KOH$ used for?

What is the product $(A)$ in the following reaction?

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

The reaction of one mole of $3-$chlorohexane with one mole of $NaI$ in the presence of acetone yields which of the following as the major product?

Predict the order of reactivity of the following compounds in $S_N1$ reaction :
$(I)$ $CH_3-CH_2-CH(Br)-CH_3$
$(II)$ $(CH_3)_2CH-CH_2-Br$
$(III)$ $(CH_3)_3CBr$

Name the following reaction: $CH_3CH_2Cl + NaI \xrightarrow{\text{acetone}} CH_3CH_2I + NaCl$