The correct order of basic strength of given aniline is:
A
o - nitroaniline > p - nitroaniline > m - nitroaniline
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
m - nitroaniline > p - nitroaniline > o - nitroaniline
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
m - nitroaniline > o - nitroaniline > p - nitroaniline
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
o - nitroaniline > m - nitroaniline > p - nitroaniline
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is D m - nitroaniline > p - nitroaniline > o - nitroaniline The pKa values of m - nitroaniline, p - nitroaniline and o - nitroaniline isomers are 2.5, 1.0 and -0.3 respectively.
Due to the presence of the electron-withdrawing nitro group, the delocalization of the lone pair of electron is improved. This effect is observed in para and ortho position.
In the ortho position, a very close inductive effect of the nitro group is also observed. (ortho effect) Hence, o - nitroaniline is less basic than p - nitroaniline.
In m - nitroaniline, only the inductive effect is present.
The decreasing order of basicity is m - nitroaniline > p - nitroaniline > o - nitroaniline.