At room temperature, the eclipsed and the staggered forms of ethane cannot be isolated because:

Arrange the following conformational isomers of n-butane in order of their increasing potential energy:

Which hydrogen in compound $\left(E\right)$ is easily replaceable during bromination reaction in presence of light ?

Isomers of hexane, based on their branching, can be divided into three distinct classes as shown in the figure.

The correct order of their boiling point is