In the presence of air,the fermentation of ethyl alcohol by $Acetobacter$ $aceti$ bacteria forms:

Toluene on reaction with reagent $A$ gives $X$. This $(X)$ forms $2,4-$dinitrophenylhydrazone and reduces ammonical silver nitrate solution. Reaction of toluene with another reagent $B$ forms $Y$,which dissolves in $NaHCO_3$ with evolution of $CO_2$. What are $A$ and $B$ respectively?

$CH_3MgBr + CO_2$ $\xrightarrow{\text{Dry ether}} Y$ $\xrightarrow{H_3O^{\oplus}} Z$
Identify $Z$ from the following.

Which of the following on hydrolysis forms acetic acid?

The end product $B$ in the sequence of reactions: $R - X$ $\xrightarrow{KCN} A$ $\xrightarrow[H_2O]{NaOH} B$ is

Identify the compound $(B)$ in the given reaction.
$CH_3Cl$ $\xrightarrow{KCN} (A)$ $\xrightarrow{H^+ / H_2O} (B)$