If formaldehyde and $KOH$ are heated,then we get

Which of the following does $NOT$ give a yellow precipitate when reacted with a $(NaOH + I_{2})$ mixture?

Consider the following sequence of reactions.
$C_6H_5COONa$ $\xrightarrow[\Delta]{NaOH/CaO} X$ $\xrightarrow[\text{Anhy. } AlCl_3]{CO/HCl} Y$ $\xrightarrow[NaOH]{\text{conc. }} A + B$.
If $A$ is the reduction product of $Y$,what is $B$?

$m$-chlorobenzaldehyde on treatment with $50 \% KOH$ solution yields

Which of the following does not react with $NaHSO_3$ (sodium bisulphite)?

The formation of cyanohydrin from ketones is an example of which type of reaction?