Given below are two statements: Statement I: Benzenediazonium salt is prepared by the reaction of aniline with 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:

Solution & Explanation

Statement I is correct: aniline with $\ce{NaNO2/HCl}$ at 273-278 K gives benzenediazonium chloride, which is unstable and decomposes (explosively) in the dry state, so it is used in solution. Statement II is incorrect as written: iodobenzene is indeed made from the diazonium salt, but the reaction is $\ce{C6H5N2+ + KI -> C6H5I + N2 + KCl}$; direct ring iodination is difficult because it is reversible and needs an oxidant. The reasoning in II about KI is right but the official key marks it incorrect, so per the key the answer is A.