What is the type of hybridisation of each carbon atom in the following compounds?
$(a)$ $CH_{3}Cl$
$(b)$ $(CH_{3})_{2}CO$
$(c)$ $CH_{3}CN$
$(d)$ $HCONH_{2}$
$(e)$ $CH_{3}CH=CHCN$

(N/A) In $CH_{3}Cl$, the carbon atom is bonded to four atoms (three $H$ and one $Cl$) with single bonds, so it is $sp^{3}$ hybridised.
$(b)$ In $(CH_{3})_{2}CO$, the two methyl carbons are $sp^{3}$ hybridised, and the carbonyl carbon $(C=O)$ is $sp^{2}$ hybridised.
$(c)$ In $CH_{3}CN$, the methyl carbon is $sp^{3}$ hybridised, and the nitrile carbon $(C \equiv N)$ is $sp$ hybridised.
$(d)$ In $HCONH_{2}$, the carbonyl carbon is $sp^{2}$ hybridised.
$(e)$ In $CH_{3}CH=CHCN$, the carbons are $sp^{3}$, $sp^{2}$, $sp^{2}$, and $sp$ hybridised respectively.