Identify $B$ in the following sequence of reactions.
Acetic acid $\xrightarrow[\Delta]{\text{Thionyl chloride}} A$ $\xrightarrow{\text{Ammonia}} B$

$A$ key step in the hydrolysis of acetamide in aqueous acid proceeds by nucleophilic addition of

The major product of the following reaction is:

The strongest acid among the following compounds is

$A$ compound $(A)$ has the molecular formula $C_2H_4O_2$ and it gives the following reactions:
$(i)$ Addition of the above compound to a sodium carbonate solution gives effervescence of $CO_2$ gas and forms compound $(P)$.
$(ii)$ When compound $(P)$ is heated with sodalime,it gives gas $(Q)$. Identify $(A)$,$(P)$,and $(Q)$ and provide the reactions.

Identify the product $B$ in the following reaction sequence:
$C_6H_5COOH$ $\xrightarrow{NaOH} A$ $\xrightarrow{\text{Electrolysis}} B$