Alcoholic solution of $KOH$ is used for

Write about the $\beta$-elimination reactions of haloalkane compounds.

$HBr$ reacts with $CH_2=CH-OCH_3$ at room temperature to give

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

Match the following:

Column $I$	Column $II$
$A$. $CH_3-CHBr-CD_3$ on treatment with alc. $KOH$ gives $CH_2=CH-CD_3$ as a major product.	$P$. $E1$ reaction
$B$. $Ph-CHBr-CH_3$ reacts faster than $Ph-CHBr-CD_3$.	$Q$. $E2$ reaction
$C$. $Ph-CH_2-CH_2Br$ on treatment with $C_2H_5OD / C_2H_5O^-$ gives $Ph-CD=CH_2$ as the major product.	$R$. $E1cb$ reaction
$D$. $PhCH_2CH_2Br$ and $PhCD_2CH_2Br$ react with same rate.	$S$. First order reaction

Which compound might be synthesized by the $S_N2$ displacement of an alkyl-halide?