Question

Assertion: Aniline hydrogen sulphate on heating forms a mixture of o- and p-amino sulphonic acid.
Reason: The sulphonic acid is ${{e}^{-}}$ withdrawing.
(A) Both Assertion and Reasons are correct and the reason is the correct explanation for the assertion.
(B) Both Assertion and Reason are correct but Reason is not the correct explanation for the assertion.
(C) Assertion is correct but the reason is wrong.
(D) Both assertion and reason are incorrect.

Answer 1

Hint: If electrophilic aromatic substitution of monosubstituted benzene is faster than that of benzene under identical conditions, the substituent in the monosubstituted benzene is called an activating group. Ortho, para directing groups are electron-donating groups; meta directing groups are electron-withdrawing groups.

Complete step by step solution:
Monosubstituted benzene, when treated with an electrophile, could undergo three electrophilic aromatic substitution reactions. Each reaction yields disubstituted benzene as the organic product, which can be identified using the descriptors ortho, meta, and para. If the relative yield of the ortho product and that of the para product are higher than that of the meta product, the substituent on the benzene ring in the monosubstituted benzene is called an ortho, para directing group. If the opposite is observed, the substituent is called a meta directing group. The halide ions, which are electron-withdrawing but ortho, para directing, are the exception.
Aniline hydrogen sulphate on heating decomposes to aniline and sulphuric acid. Sulphonation of aniline with sulphuric acid takes place at ortho and para positions since the ($-N{{H}_{2}}$) group is ortho and para directing.
So, Both Assertion and Reason are correct but Reason is not the correct explanation for the assertion,

Hence, the correct answer is the (B) option.

Note: If electrophilic aromatic substitution of monosubstituted benzene is slower than that of benzene under identical conditions, the substituent in the monosubstituted benzene is called a deactivating group.