The reaction sequence is as follows:
$Cyclopentanecarboxamide$ $\xrightarrow{P_2O_5, \Delta} W$ $\xrightarrow{CH_3MgBr, H_3^+O} X$ $\xrightarrow{Ca(OH)_2, I_2 (\text{yellow ppt.})} Y$ $\xrightarrow{\Delta} Z$
$Z$ is:

Which of the following reagents can be used to distinguish between an aldehyde and a ketone?

Identify $A$ and $B$ in the given chemical reaction sequence :-

The reaction in which $NaCN/C_2H_5OH/HOH$ is used is:

$(A)$ and $(B)$ in the following reaction sequence are:
$RR'C=O$ $\xrightarrow{HCN} (A)$ $\xrightarrow{B} RR'C(OH)CH_2NH_2$

Two aliphatic aldehydes $P$ and $Q$ react in the presence of aqueous $K_2CO_3$ to give compound $R$,which upon treatment with $HCN$ provides compound $S$. On acidification and heating,$S$ gives the product shown below:
$1.$ The compounds $P$ and $Q$ respectively are:
$2.$ The compound $R$ is:
$3.$ The compound $S$ is:
Give the answer for questions $1$,$2$ and $3$.