Which of the following substances is known as oil of wintergreen?

$n$-Propanol on treatment with concentrated $HBr$ gives $P$. The product $P$ on reaction with $KCN$ gave the product $Q$. The product $Q$ on heating with aqueous acidic solution,furnished the product $R$. The product $R$ is

Number of compounds from the following which will not dissolve in cold $NaHCO_3$ and $NaOH$ solutions but will dissolve in hot $NaOH$ solution is $........$.

If the rate of the reaction,$R-CO-Z + Nu^- \rightarrow R-CO-Nu + Z^-$ is fastest,then $Z$ is

In the following sequence of reactions,$CH_3-Br$ $\xrightarrow{KCN} A$ $\xrightarrow{H_3O^{+}} B$ $\xrightarrow[ether]{LiAlH_4} C$,the end product $(C)$ is:

$CH_3COOH \xrightarrow{\Delta, P_2O_5} X$. Identify $X$.