What are $A, B$ and $C$ in the following reaction sequence?
$CH_2=CH_2$ $\xrightarrow{HBr} A$ $\xrightarrow{KCN} B$ $\xrightarrow{H^{+} / H_2O} C$

In the reaction sequence,$C_2H_5Cl + KCN$ $\xrightarrow{C_2H_5OH} X$ $\xrightarrow{H_3O^{\oplus}, \Delta} Y$. What is the molecular formula of $Y$?

The acid formed when propyl magnesium bromide is treated with carbon dioxide is:

What is obtained when glycerol is heated with oxalic acid at $110\,^{\circ}C$?

Consider the following reactions. From these reactions,which reaction will give carboxylic acid as a major product?
$(A)$ $R-C \equiv N \xrightarrow[(i) H^{+}/H_2O]{\text{mild condition}} R-CONH_2$
$(B)$ $R-MgX \xrightarrow[(ii) H_3O^{+}]{\text{(i) } CO_2} R-COOH$
$(C)$ $R-C \equiv N \xrightarrow[(ii) H_3O^{+}]{\text{(i) } SnCl_2/HCl} R-CHO$
$(D)$ $R-CH_2-OH \xrightarrow{PCC} R-CHO$
$(E)$ $\text{Benzoyl chloride} \xrightarrow[(ii) Br_2/H_2O]{\text{(i) } H_2/Pd-BaSO_4} \text{Benzoic acid}$
Choose the correct answer from the options given below:

Which reaction is suitable for the preparation of $\alpha$-chloroacetic acid?