The reaction shown below is:

An optically active alkyl bromide $C_4H_9Br$ reacts with ethanolic $KOH$ to form major compound $[A]$,which reacts with bromine to give compound $[B]$. Compound $[B]$ reacts with ethanolic $KOH$ and sodamide to give compound $[C]$. One molecule of water adds to compound $[C]$ on warming with mercuric sulphate and dilute sulphuric acid at $333 \text{ K}$ to form compound $[D]$. The functional group in compound $[D]$ will be confirmed by:

Which of the following compounds will react with ethanolic $KCN$?

Which of the following does not respond to Fehling's solution test and haloform reaction but shows Cannizzaro's reaction?

The addition of $HCN$ to carbonyl compounds is an example of

Identify the reagent $R$ used in the following reaction:
$\text{Ketone} \xrightarrow{R} \text{Semicarbazone}$