What is the product obtained by the partial hydrolysis of acetonitrile with cold concentrated $HCl$?

The reaction $CH_3-CH=CH_2 \xrightarrow{(CO + H_2O)/H^{+}} CH_3-CH(COOH)-CH_3$ is known as:

What is the initial product obtained from the hydrolysis of cyanide?

In the above reaction,the reagent $A$ is :

Malonic acid can be prepared from acetic acid using which combination of chemicals in the proper sequence?

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: