The correct reactivity order for $E_2$ reaction with alcoholic $KOH$ will be:
$(i)$ $3-$chlorocyclohexene derivative (conjugated system)
(ii) $1-$chlorodecalin derivative (with double bond)
(iii) $1-$chlorodecalin (saturated)

For the following compounds,the correct statement$(s)$ with respect to nucleophilic substitution reactions is(are):
$I$: Benzyl bromide $(C_6H_5CH_2Br)$
$II$: Cyclohexylmethyl bromide $(C_6H_{11}CH_2Br)$
$III$: tert-Butyl bromide $((CH_3)_3CBr)$
$IV$: $1-$Phenylethyl bromide $(C_6H_5CH(CH_3)Br)$
$A$. $I$ and $III$ follow $S_{N}1$ mechanism
$B$. $I$ and $II$ follow $S_{N}2$ mechanism
$C$. Compound $IV$ undergoes inversion of configuration
$D$. The order of reactivity for $I$,$III$ and $IV$ is: $IV > I > III$

Which of the following is an example of an $S_N2$ reaction?

$A$ halide $C_5H_{11}Br$ on treatment with alc. $KOH$ gives $2$-pentene only. The halide will be

Explain the order of reactivity of $1^o$,$2^o$,and $3^o$ halides towards the $S_N2$ reaction.

Which of the following compounds would undergo $S_N1$ reaction faster and why?
$(A)$ Cyclohexylmethyl chloride
$(B)$ Benzyl chloride