Which one of the following is used for the purification of aldehydes?

For the given compound,determine the number of hydrogen atoms that are replaced by $D$ upon keeping it for a long time with $\mathop O\limits^\ominus D / D_2O$.

Which of the following carbonyl compounds forms the most stable hydrate when $H_2O$ is added across the $C=O$ group?

The major product $(Y)$ in the following reactions is
$CH_3-CH(CH_3)-C\equiv CH$ $\xrightarrow[H_2O]{HgSO_4, H_2SO_4} X$ $\xrightarrow[(ii) \ conc. H_2SO_4 / \Delta]{(i) \ C_2H_5MgBr, H_2O} Y$

The reactants $(A)$ and $(B)$ are:

Identify $A$ and $B$ from the following reactions:
$(I)$ $CH_3-CH=CH-CH_3 \xrightarrow{\text{(i) } O_3}{\text{(ii) } Zn-H_2O} 2X$
$(II)$ $2X$ $\xrightarrow[2. \Delta]{1. NaOH \text{ (dil.)}} Z$ $\xrightarrow[\text{(ii) } Zn-H_2O]{\text{(i) } O_3} A + B$