(a)Benzenediazonium salt react with water to yield benzene(b)Fluro benzene can be obtained from benzenediazonium salt by adding the reagent KF followed by heating(c)PhN⊕2 couples with PhNMe2 and not with PhCH3(d)Me−C6H5 is active to couple with P−N⊕2−C6H4−NMe2
