The formation of an innumerable number of carbon compounds is due to its:

Styrene on reaction with reagent $X$ gave $Y$, which on hydrolysis followed by oxidation gave $Z$. $Z$ gives a positive $2,4-DNP$ test but does not give the iodoform test. What are $X$ and $Z$ respectively?

When a hydrocarbon $A$ undergoes complete combustion,it requires $11$ equivalents of oxygen and produces $4$ equivalents of water. What is the molecular formula of $A$?

Identify $(A)$.

When the hydrogen atom in isocyanic acid $(HNCO)$ is replaced by a methyl group,the resulting compound undergoes rearrangement to form which product?

The end product formed in the above reaction is: