What is incorrect order of stability?
$\left(\mathrm{I}\right)$
$\left(\mathrm{I}\mathrm{I}\right)$
$\left(\mathrm{I}\mathrm{I}\mathrm{I}\right)$ Boat form of $1,\mathrm{}4-\mathrm{c}\mathrm{y}\mathrm{c}\mathrm{l}\mathrm{o}\mathrm{h}\mathrm{e}\mathrm{x}\mathrm{a}\mathrm{n}\mathrm{d}\mathrm{i}\mathrm{o}\mathrm{l}\mathrm{}>\mathrm{C}\mathrm{h}\mathrm{a}\mathrm{i}\mathrm{r}\mathrm{}\mathrm{f}\mathrm{o}\mathrm{r}\mathrm{m }\mathrm{}\mathrm{o}\mathrm{f }\mathrm{}\mathrm{1,4}-\mathrm{c}\mathrm{y}\mathrm{c}\mathrm{l}\mathrm{o}\mathrm{h}\mathrm{e}\mathrm{x}\mathrm{a}\mathrm{n}\mathrm{d}\mathrm{i}\mathrm{o}\mathrm{l}$
$(\mathrm{I}\mathrm{V})$
$\left(\mathrm{V}\right)$ Gauche form of succine acid > Anti from of succinic acid

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