Identify the reagent involved in the Sandmeyer reaction.

Which of the following are intermediates in the Sandmeyer reaction?
$(i)$ $C_6H_5N^{+} \equiv NCl^{-}$
$(ii)$ $C_6H_5N^{+} \equiv N$
$(iii)$ $\overset{\centerdot }{C}_6H_5$
$(iv)$ $C_6H_5Cl$

Describe the preparation of aryl halides from aromatic hydrocarbons and from amines via the Sandmeyer reaction.

What is the name of the reaction involving the replacement of a diazonium group by a chloride ion using a cuprous $(I)$ salt?

In this process,the product $A$ is:

Which of the following reactions uses a diazonium salt as a reactant?