The major products $P$ and $Q$ are

Oxalic acid + $A \rightarrow$ Glycerol monooxalate. If $A \xrightarrow{conc.\,H_2SO_4} B$,then $B$ is:

In the given reaction sequence,identify the correct reagents to prepare $A$ from $B$. The starting material is benzenesulfonic acid. The reaction with $\Delta / H_3O^+$ yields $B$ (benzene),and the reaction with $1. \text{Fused } NaOH, 2. H^+$ yields $A$ (phenol). Therefore,to prepare $A$ (phenol) from $B$ (benzene),the correct sequence of reagents is:

Consider all steps and intermediates. Which of the following is a correct statement?

$p-$Cresol reacts with chloroform in an alkaline medium to give compound $A$,which reacts with hydrogen cyanide to form compound $Y$. Hydrolysis of $Y$ gives a chiral carboxylic acid. Identify the structure of the carboxylic acid.

$(i)$ Draw the structures of all isomeric alcohols of molecular formula $C_5H_{12}O$ and give their $IUPAC$ names.
$(ii)$ Classify the isomers of alcohols in question $(i)$ as primary,secondary and tertiary alcohols.