Why preparation of aryl iodide by electrophillic substitution requires presence of an oxidising agent? why can arylflouride not be prepared by this method?

Open in App

Solution

During the electrophilic substitution of aromatic hydrocarbon, HI is produced during the reaction.Since it is a good reducing agent, it reduces the aryl iodide back to the aromatic hydrocarbon and iodine i.e the reaction is reversible.Therefore, oxidising agents such as HNO₃, HgO etc. are used to remove HI produced in the reaction as follows:
4HI + 2 HNO₃â†’ 2N₂O₃ + 3H₂O + 2I₂
Arylfluorides, cannot be prepared by this method due to high reactivity fluorine since the reaction is very violent.

Suggest Corrections

Similar questions

Method of preparation of haloarenes by electrophilic substitution reaction

Q. Why only ortho and para isomers can be easily separated by electrophilic substitution and not the meta isomers ?

The given set up in the figure is for the preparation of an acid.
(a) Name the acid prepared by this method.
(b) Name the reactants used.
(c) Why is an empty flask used?
(d) What is the drying agent used? Why is this drying agent chosen?
(e) What is the role of the inverted funnel in the arrangement?

Q. The given set up is for the preparation of an acid. [5 MARKS]

(a) Name the acid prepared by this method.
(b) Name the reactants used.
(c) Why is empty flask used?
(d) What is the drying agent used? Why is this drying agent chosen?
(e) What is the role of inverted funnel in the arrangement?

Q. Hydrogen can be prepared by mixing steam and water gas at 673 K in presence of

F e_{2} O_{3}

and

C r_{2} O_{3}

. This process is called:

Join BYJU'S Learning Program