In the following skew conformation of ethane, $\mathrm{H}^{\prime}-\mathrm{C}-\mathrm{C}-\mathrm{H}^{\prime \prime}$ dihedral angle is :

• A

  $58^{\circ}$
• Correct answer
  B

  $149^{\circ}$
• C

  $151^{\circ}$
• D

  $120^{\circ}$

Solution

$$ \therefore \quad \text { Angle between } \mathrm{H}^{\prime} \text { and } \mathrm{H}^{\prime \prime}=120^{\circ}+29^{\circ}=149^{\circ} $$

Hence, the correct answer is option: 'B'.