Chemistry - Nomenclature Question with Solution | TestHub

(a)

Numbering starts from $>\mathrm{C}=\mathrm{O}$ as it is the principal functional group, goes in clockwise direction in order to give lower number to double bond.

(b)

-OH is the principal function group, hence it is phenol derivative not toluene derivative.

Correct IUPAC name is 3-methyl phenol, meta-methyl can also be used.

(c)

-CN has higher priority than -OH group, hence the compound is hydroxyl benzonitrile not cyanophenol. Correct IUPAC name is 3-hydroxy benzonitrile, meta-hydroxy can also be used.

(d) Given compound is a methyl ester of benzene sulphonic acid, hence the given name is correct.