Question
During preparation of arenediazonium salts, the excess of nitrous acid, if any, is destroyed by adding
A.
$${\text{aq}}{\text{.}}\,NaOH$$
B.
$${\text{aq}}{\text{.}}\,N{a_2}C{O_3}$$
C.
$${\text{aq}}{\text{.}}\,N{H_2}CON{H_2}$$
D.
$${\text{aq}}{\text{.}}\,KI$$
Answer :
$${\text{aq}}{\text{.}}\,N{H_2}CON{H_2}$$
Solution :
Urea decomposes $$HN{O_2}$$ to give $${N_2},C{O_2}$$ and $${H_2}O$$
$$N{H_2}CON{H_2} + 2HN{O_2} \to $$ $$2{N_2} \uparrow + C{O_2} \uparrow + 3{H_2}O$$