Question

Dihedral angle of least stable conformer of ethane is :

• A. $0^{\circ }$
• B. ${120}^{\circ }$
• C. ${180}^{\circ }$
• D. $60^{\circ }$

Answer 1

The correct option is A $0^{\circ }$

Ethane has two conformers
(i) Eclipsed
(ii) Staggered

Eclipsed conformer is least stable while staggered conformer is most stable. In eclipsed conformer the dihedral angle is $0^{\circ }$