Question

what is diazotisation

Answer 1

Diazonium is a group of organic compounds sharing a common functional group R-N2+ X− where R can be any organic residue such alkyl  and X is an inorganic or organic anion such as a halogen.

Answer 2

The most important method for the preparation of diazonium salts is treatment of aromatic amines such as aniline with nitrous acid. Usually the nitrous acid is generated in situ (in the same flask) from sodium nitrite and mineral acid.
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