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JEE Main levelSingle correct optionDifficulty 2 of 3hx008

Direct iodination of benzene with $I X_{2}$ alone is reversible and gives little iodobenzene, but the reaction proceeds when a little $HNO X_{3}$ is added. The role of $HNO X_{3}$ is to

Areduce $I X_{2}$ to $I X^{-}$ so that it acts as a nucleophile
Bdehydrate benzene to make it more reactive
Cnitrate benzene first so that iodine can replace the nitro group
Doxidise the $HI$ formed back to $I X_{2}$ , preventing the reverse reaction

Answer: D

C X_{6} H X_{6} + I X_{2} C X_{6} H X_{5} I + HI

is reversible because

HI

is a strong reducing agent and reduces iodobenzene back to benzene. An oxidising agent such as

HNO X_{3}

removes

HI

by oxidising it to

I X_{2}

, so the equilibrium shifts forward.

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