In the reaction $R - X$ $\xrightarrow[\text{alcoholic}]{KCN} A$ $\xrightarrow[\Delta]{H_2O/H^\oplus} B$,product $(B)$ is

When $methyl \ cyanide$ is hydrolysed in the presence of an alkali,the final product is:

Which of the following gives benzoic acid on oxidation?

In this reaction,product $X$ is
$CH_3-CH_2-Br$ $\xrightarrow{alc. KCN} CH_3CH_2CN$ $\xrightarrow{HOH} X$

Identify the product $B$ in the following reaction.
Dry ice $\xrightarrow[\text{dry ether}]{CH_3MgBr} A$ $\xrightarrow{H_3O^{+}} B$

What will be the final product of the following reaction sequence?
$CH \equiv CH$ $\xrightarrow{CH_3MgBr}$ $\xrightarrow{CO_2/H_3O^+}$ $\xrightarrow{HgSO_4/H_2SO_4}$ $\xrightarrow{Ag_2O, \Delta} ?$