KCET2026ChemistryAmines
Nitration of aniline in strong acidic medium gives significant amount of m-nitroaniline because
Options
- AIn electrophilic substitution reaction, amino group is meta directing
- BIn strong acidic medium, aniline is present as anilinium ion.
- C- NH ₂ group always directs to meta position.
- Dm-nitroaniline has higher molar mass than o & p nitroanilines.
Correct answer
B. In strong acidic medium, aniline is present as anilinium ion.
Step-by-step solution
In a strong acidic medium, aniline undergoes protonation to form the anilinium ion ( - NH ₃^+ ). The - NH ₃^+ group is strongly deactivating and meta-directing in nature. Due to the formation of this anilinium ion, electrophilic substitution (nitration) occurs at the meta position, yielding a significant amount of m-nitroaniline (about 47 % ). The - NH ₂ group itself is ortho and para directing, but its protonated form directs the incoming electrophile to the meta position. Answer: In strong acidic medium, aniline