Question

Dihedral angle between two methyl groups of $n$-butane in the gauche and anti forms are:

• A. ${60}^{},0^{}$
• B. $0^{},{60}^{}$
• C. ${60}^{},{180}^{}$
• D. ${180}^{},{60}^{}$

Answer 1

The correct option is C ${60}^{},{180}^{}$

In the above figure of conformational isomers of n-butane, angle between 2 methyl groups in 2 gauche form is ${60}^0$ and angle between 2 methyl groups in anti-form is ${180}^0$