What will be the order of reactivity of the following carbonyl compounds with a nucleophile?
$(I)$ $HCHO$
$(II)$ $CH_3CHO$
$(III)$ $(CH_3)_2CO$
$(IV)$ $(Me_3C)_2CO$

The major product in the following reaction sequence is

The compound $(P)$ undergoes the following reaction sequence: $(P)$ $\xrightarrow{\Delta} X$ $\xrightarrow{Zn-Hg/HCl} Y$. Identify $Y$.

$(EtO)_2CH-CHO + CH_3MgI \xrightarrow{H_3O^{+}} (A)$. The product obtained in the above reaction is:

Which of the following can be distinguished by the iodoform reaction?

Which of the following reagents must be used in the given interconversion? The reaction involves the reduction of $4$-hydroxycyclohexanone to cyclohexanol,where the carbonyl group is reduced to a methylene group while the hydroxyl group remains unaffected.