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Given below are two statements:
Statement I: Benzenediazonium salt is prepared by the reaction of aniline with nitrous acid at 273-278 K. It decomposes easily in the dry state.
Statement II: Insertion of iodine into the benzene ring is difficult and hence iodobenzene is prepared through the reaction of benzenediazonium salt with KI.
In the light of the above statements, choose the most appropriate answer from the options given below:
Statement I: Benzenediazonium salt is prepared by the reaction of aniline with nitrous acid at 273-278 K. It decomposes easily in the dry state.
Statement II: Insertion of iodine into the benzene ring is difficult and hence iodobenzene is prepared through the reaction of benzenediazonium salt with KI.
In the light of the above statements, choose the most appropriate answer from the options given below:
A
Both Statement I and Statement II are correct
B
Both Statement I and Statement II are incorrect
C
Statement I is correct but Statement II is incorrect
D
Statement I is incorrect but Statement II is correct
Explanation
Both statements are correct: diazotization occurs at $0-5^\circ\text{C}$ and dry diazonium salt is explosive; direct iodination is reversible, so iodobenzene is prepared by treating diazonium salt with KI.
Detailed Solution
Statement I is correct: Aniline reacts with nitrous acid ($\text{NaNO}_2 + \text{HCl}$) at $273-278\text{ K}$ ($0-5^\circ\text{C}$) to form benzenediazonium chloride; in the dry solid state, diazonium salts are dangerously unstable and explode upon mild disturbance. Statement II is correct: Direct electrophilic iodination of benzene is reversible due to the generation of reducing agent HI and requires strong oxidizing agents ($\text{HNO}_3, \text{HIO}_3$); hence iodobenzene is conveniently prepared by treating benzenediazonium chloride solution with aqueous potassium iodide (KI).