$A$ carbonyl compound $X$ $(C_8H_8O)$ gives a yellow precipitate with $NaOI$. The hemiacetal of $X$ with methanol/dry $HCl$ is:

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 $3$.

Which of the following will undergo aldol condensation?

The reaction shown above is a Baeyer-Villiger rearrangement of an asymmetric ketone with magnesium monoperoxyphthalate hexahydrate (in the drawing,$Mg^{+2}$ is omitted for clarity). Identify the major product.

$A$ strong base can abstract an $\alpha$-hydrogen from

Identify the compound obtained when ethyl methyl ketone is treated with $CH_3MgBr$ followed by hydrolysis.