Ethyl bromide gives ethylene when reacted with

$A$ small amount of alcohol is added to a bottle of $CHCl_3$ because .............

Which of the following compounds is optically inactive?

The major product of the following reaction is:
(Structure of $4-$bromo-pent$-2-$en$-2-$amine derivative) $\xrightarrow[{S_N2}]{{KOH}}$

An alkyl halide $C_3H_7Cl$,on reaction with a reagent $X$ gave the major product $Y$ $(C_4H_7N)$. $Y$ on hydrolysis released a gas,which turns red litmus to blue. What are $X$ and $Y$?

Identify $A$ and $B$ in the following reaction:
$C_2H_5Cl \xrightarrow{A} C_2H_5OH \xleftarrow{B} C_2H_5Cl$