Most reactive compound toward $S_N1$ is

The major product of the following reaction is:

The compound that will undergo $S_N 1$ reaction with the fastest rate is

Consider the reaction: $1$-methylcyclopentene $+ HBr \xrightarrow{CCl_4} \text{Product}$. Comment upon the optical activity of the product.

How many different products are formed from the $E_2$ elimination reaction of the following alkyl iodide?

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)