Presence of which of the following is suitable for the synthesis of bromobenzene from benzene diazonium salts?

Aryl chlorides and bromides can be easily prepared by electrophilic substitution of arenes with chlorine and bromine respectively in the presence of Lewis acid catalysts. But why does the preparation of aryl iodides require the presence of an oxidizing agent?

The raw material for the Raschig process is

Toluene is nitrated and the resulting product is reduced with tin and hydrochloric acid. The product so obtained is diazotised and then heated with cuprous bromide. The reaction mixture so formed contains

How can fluorobenzene be prepared in the laboratory?

The chlorobenzene is generally obtained from a corresponding diazonium salt by reacting it with