$C_2H_5Br$ $\xrightarrow{KCN} A$ $\xrightarrow{\text{Hydrolysis}} B$
The compound $A$ in the above reaction is

Two isomers $(A)$ and $(B)$ with molar mass $184 \ g/mol$ and elemental composition $C, 52.2 \ \%; H, 4.9 \ \%$ and $Br, 42.9 \ \%$ give benzoic acid and $p$-bromobenzoic acid,respectively,on oxidation with $KMnO_4$. Isomer '$A$' is optically active and gives a pale yellow precipitate when warmed with alcoholic $AgNO_3$. Isomer '$A$' and '$B$' are,respectively .... .

Which of the following alkyl halides has the lowest boiling point?

Consider the following anions:
$(I)$ $CF_3SO_3^-$
$(II)$ $C_6H_5SO_3^-$
$(III)$ $C_6H_5O^-$
$(IV)$ $CH_3COO^-$
When attached to $sp^3$ hybridized carbon,their leaving group ability in nucleophilic substitution reaction decreases in the order:

Chloroform is slowly oxidized by air in the presence of light to form:

The correct order for increasing reactivity towards $S_N1$ substitution for the following compounds is:
$1. CH_3CH_2Br$
$2. CH_2=CHCH(Br)CH_3$
$3. CH_2=CHBr$
$4. CH_3CH(Br)CH_3$