Pick out the correct statement.

• A

  Both glycine and p-aminobenzoic acid form dipoler ions
• B

  Both sulphanilic acid and p-aminobenzoic acid form dipolar ions
• C

  Glycine does not form dipolar ion, but p-aminobenzoic acid forms dipolar ion
• Correct answer
  D

  Both sulphanilic acid and glycine form dipolar ions, but p-aminobenzoic acid does not form dipolar ion

Solution

The aliphatic $-\mathrm{N}{\mathrm{H}}_2$ is sufficiently basic to accept ${\mathrm{H}}^{+}$ from $-\mathrm{C}\mathrm{O}\mathrm{O}\mathrm{H}$ group in glycine, $\mathrm{N}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{C}\mathrm{O}\mathrm{O}\mathrm{H}$ . The $-\mathrm{C}\mathrm{O}\mathrm{O}\mathrm{H}$ is not strong enough to donate ${\mathrm{H}}^{+}$ to the weakly basic aromatic $\mathrm{N}{\mathrm{H}}_2$ in p-aminobenzoic acid, The $-\mathrm{S}{\mathrm{O}}_3\mathrm{H}$ is a sufficiently strong acid to donate ${\mathrm{H}}^{+}$ to weakly basic aromatic $\mathrm{N}{\mathrm{H}}_2$ .

Hence, the correct answer is option: 'D'.