Explain the following name reactions :
Sandmeyer reaction

Explanation

Sandmeyer reaction : Formation of chloro benzene, Brono benzene (or) cyano benzene from benzene diazonium salts with reagents `Cu_(2)Cl_(2)//HCl, Cu_(2)Br_(2)//HBr, CuCN//KCN` is called sandmayers reaction.
`C_(6)H_(5)N_(2).^(+)X^(-) overset(Cu_(2)Cl_(2)//HCl) to C_(6)H_(5)Cl+N_(2)`
`C_(6)H_(5)N_(2).^(+)X^(-) overset(Cu_(2)Br_(2)//HBr) to C_(6)H_(5)Br+N_(2)`
`C_(6)H_(5)N_(2).^(+)X^(-) overset(CuCN//KCN) to C_(6)H_(5)CN+N_(2)`