On prolonged heating of ammonium cyanate or urea,we get

For the diazonium ions,the order of reactivity towards the diazo-coupling with phenol in the presence of dilute $NaOH$ is:
$(I)$ $Me_2N-C_6H_4-N_2^+$
$(II)$ $O_2N-C_6H_4-N_2^+$
$(III)$ $CH_3O-C_6H_4-N_2^+$
$(IV)$ $CH_3-C_6H_4-N_2^+$

Which of the following amines will not react with nitrous acid to give nitrogen gas?

The basic character of amines can be explained by which of the following theories?

Arrange the following compounds in decreasing order of basic strength:
$(i)$ Aniline
(ii) $p$-Nitroaniline
(iii) $p$-Cyanoaniline
(iv) $p$-Toluidine

The main product of the following reaction will be: