There is free rotation about the carbon-carbon σ-bond in ethane. This means that the energy difference between the staggered and eclipsed conformers is

Question

There is free rotation about the carbon-carbon σ-bond in ethane. This means that the energy difference between the staggered and eclipsed conformers is (A) 3 kJ mol -1 (B) 23 kJ mol -1 (C) 13 kJ mol -1 (D) 17 kJ mol -1

Tardigrade Admin · Accepted Answer

The staggered conformer is more stable than the eclipsed conformer by about 12.6 kJ mol -1. As this energy difference is small, there is no effective energy barrier to rotation about a σ bond.

Q. There is free rotation about the carbon-carbon $σ$ -bond in ethane. This means that the energy difference between the staggered and eclipsed conformers is

$3 k J m o l^{- 1}$

$23 k J m o l^{- 1}$

$13 k J m o l^{- 1}$

$17 k J m o l^{- 1}$

The staggered conformer is more stable than the eclipsed conformer by about $12.6 k J m o l^{- 1}$ . As this energy difference is small, there is no effective energy barrier to rotation about a $σ$ bond.

Q. There is free rotation about the carbon-carbon σ-bond in ethane. This means that the energy difference between the staggered and eclipsed conformers is

3kJmol−1

23kJmol−1

13kJmol−1

17kJmol−1