The end product of the reactions is
$C_2H_5NH_2$ $\xrightarrow{HNO_2} A$ $\xrightarrow{PCl_5} B$ $\xrightarrow{NH_3} C$

Considering the basic strength of amines in aqueous solution,which one has the smallest $pK_b$ value?

Which one of the following compounds does not react with acetyl chloride?

Identify the product $C$ in the following reaction sequence:
$C_6H_5COOH$ $\xrightarrow{NH_3, \Delta} A$ $\xrightarrow{Br_2, KOH} B$ $\xrightarrow{CHCl_3, KOH} C$

The increasing order of nucleophilicity of the following nucleophiles is: $a. CH_3CO_2^-$,$b. H_2O$,$c. CH_3SO_3^-$,$d. OH^-$

Reaction of $R-CONH_2$ with a mixture of $Br_2$ and $KOH$ gives $R-NH_2$ as the main product. The intermediates involved in this reaction are :-
$(A)$ $R-CONHBr$
$(B)$ $R-NH-Br$
$(C)$ $R-N=C=O$
$(D)$ $R-CONBr_2$