Dihedral angle in staggered form of ethane is
- 0
- 120
- 60
- 180
Answer
(3) 60
Solution
In the Newman projection of the staggered conformation, the three C–H bonds of the rear carbon lie exactly midway between the three C–H bonds of the front carbon:
[figure]
∵ The front bonds are 120 apart and each rear bond bisects the angle between two front bonds.
⇒ Dihedral (torsional) angle between the nearest C–H bonds = 120 2 = 60
(In the eclipsed form the dihedral angle is 0 .)
Answer: (3)