Question

Following statements are given regarding the preparation of aryl halides from toluene. Read the following statements and choose the correct options.
(i) Aryl chlorides and bromides can be easily prepared by this method.
(ii) The ortho and para isomers formed in the reaction can not be separated easily due to small difference in their melting point.
(iii) Reactions with iodine are reversible in nature and require the presence of an oxidising agent.
(iv) Fluoro compounds are not prepared by this method due to low reactivity of fluorine.

• A. (i) and (iii) are correct
• B. (ii) and (iv) are correct
• C. (i), (ii), and (iii) are correct
• D. All statements are correct

Answer 1

Answer: (A)

Aryl chlorides and bromides can be easily prepared by electrophilic substitution of arenes with chlorine and bromine respectively in the presence of Lewis acid catalyst like iron or iron (III) chloride.
The ortho and para isomers can be easily separated due to large difference in their melting points. Reactions with iodine are reversible in nature and require the presence of an oxidising agent $\left( HNO _{3}, HIO _{4}\right)$ to oxidise the $HI$ formed during iodination. Fluoro compounds are not prepared by this method due to high reactivity of fluorine.