Question

Which of the following is the correct order of stability of the following four distinct conformations of n-butane?

• A. Staggered > Gauche >Partially eclipsed > Fully eclipsed
• B. Gauche Staggered > Partially Eclipsed > Fully eclipsed
• C. Staggered > Partially eclipsed > Gauche >Fully eclipsed
• D. Fully eclipsed > Staggered >Partially eclipsed > Gauche

Answer 1

The correct option is A

Staggered > Gauche >Partially eclipsed > Fully eclipsed

Correct option is (a).
Staggered > Gauche > Partially eclipsed > Fully eclipsed.

Staggered is the most stable as the two methyl groups are anti to each other. In fully eclipsed form the two methyl groups are syn to each other ( $0^o$ dihedral angle) angle.