Identify the reagent $R$ necessary to bring about the following conversion: $C_6H_5COCl \xrightarrow{R} C_6H_5COOH$.

The following species are involved in the formation of an ester from a carboxylic acid in the presence of acid. The correct sequence of formation of these species is

When ethane-$1, 2$-dioic acid is heated with conc. $H_2SO_4$,it gives

An organic compound is boiled with alcoholic potash. The product is cooled and acidified with $HCl$,resulting in the precipitation of a white solid. What could be the starting compound?

In the presence of a small amount of phosphorus,aliphatic carboxylic acids react with chlorine or bromine to yield a compound in which $\alpha$-hydrogen has been replaced by a halogen. This reaction is known as:

In the quick vinegar process of acetic acid,the temperature of the mixture is ......... $K$.