Which of the following is most reactive towards alcoholic $KOH$?

Rank the following groups in order of decreasing leaving group ability:
$(i)$ $-OSO_2C_6H_4CH_3$ (tosylate)
(ii) $-OCOCH_3$ (acetate)
(iii) $-OCH_3$ (methoxide)
(iv) $-OSO_2CF_3$ (triflate)

The correct description of the product in the following reaction is:
$CH_3-CH(Br)-CH_2OCH_3 \text{ } ((R)) \xrightarrow{NaCN, \text{acetone}} CH_3-CH(CN)-CH_2OCH_3$

Tertiary alkyl halides are practically inert to $SN^2$ mechanism because of....

The order of $S_{N^1}$ reactivity in aqueous acetic acid solution for the compounds:
$(1)$ $CH_3-CO-CH_2-Cl$
$(2)$ $CH_3-CH_2-CH_2-Cl$
$(3)$ $(CH_3)_3C-Cl$

Which of the following will have an enantiomer?