The correct order of heats of combustion of the following compounds is:
$(I)$ Cyclopropane
$(II)$ Cyclobutane
$(III)$ Cyclopentane

Which is the most precise designation of stereochemistry for the products formed in the electrophilic addition of $DBr$ to $1$-methylcyclohexene? ($D = {}^2H$,an isotope of hydrogen)

The end product formed in the above reaction is:

When the hydrogen atom in isocyanic acid $(HNCO)$ is replaced by a methyl group,the resulting compound undergoes rearrangement to form which product?

To achieve the above conversion,the reagents used will be

What is the acid $(A)$ obtained in the following reaction sequence?
${C_2H_5I}$ $\xrightarrow{\text{alc. KOH}} X$ $\xrightarrow[CCl_4]{Br_2} Y$ $\xrightarrow{KCN} Z$ $\xrightarrow{H_3O^+} A$