Arrange the following compounds in their correct order of $pK_b$ values.

Assertion : Acetamide reacts with $Br_2$ in presence of methanolic $CH_3ONa$ to form methyl $N$-methylcarbamate.
Reason : Methyl isocyanate is formed as an intermediate which reacts with methanol to form methyl $N$-methylcarbamate.

Alkyl benzene sulphonates can be used as detergents in hard water,unlike soaps,as

For the transformation shown below,the reagent used is:
$3-bromobenzenediazonium \ chloride \rightarrow \text{bromobenzene}$

$A$ primary amine,$RNH_2$ can be reacted with $CH_3-X$ to get a secondary amine,$RNHCH_3$,but the disadvantage is that $3^o$ amine and quaternary ammonium salts are also obtained as side products. Can you suggest a method where $RNH_2$ forms only $2^o$ amine?

Acetic acid on heating with $NH_3$ forms $A$. When $A$ reacts with $LiAlH_4$ followed by hydrolysis,it gives $B$. When $B$ is heated with chloroform in $KOH$ medium,it gives $C$. What are $B$ and $C$ respectively?