Question: 74. Given below are two statements:
Statement I: Benzenediazonium salt is prepared by the reaction of aniline with nitrous acid at 273-278 \mathrm{~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:
(1) Both Statement I and Statement II are correct
(2) Both Statement I and Statement II are incorrect
(3) Statement I is correct but Statement II is incorrect
(4) Statement I is incorrect but Statement II is correct
Answer: Option (1)
Explanation:
Statement I is correct. Benzenediazonium salts are prepared by diazotization of aniline using nitrous acid at low temperatures in the range of 273-278 \mathrm{~K}.
These salts are unstable and decompose easily in the dry state, often with evolution of nitrogen gas.
Statement II is also correct. Direct iodination of benzene is difficult due to the low reactivity of iodine in electrophilic substitution reactions.
Therefore, iodobenzene is commonly prepared by treating benzenediazonium salts with potassium iodide, where the diazonium group is replaced by iodine.
Since both statements are correct,
the correct answer is Option (1).