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

• Correct answer
  A

  $\mathrm{I}<\mathrm{III}<\mathrm{IV}<\mathrm{II}$
• B

  $\mathrm{I}<\mathrm{IV}<\mathrm{III}<\mathrm{II}$
• C

  $\mathrm{II}<\mathrm{IV}<\mathrm{III}<\mathrm{I}$
• D

  $\mathrm{II}<\mathrm{III}<\mathrm{IV}<\mathrm{I}$

Solution

The order Potential energy of above conformations is Fully eclipsed $>$ Partial eclipsed $>$ Gauche $>$ Anti

Hence, the correct answer is option: 'A'.