Question

The correct statement regarding the comparison of staggered and eclipsed conformations of ethane is

• A. The eclipsed conformation of ethane is more stable than staggered conformation, because eclipsed conformation has no torsional strain
• B. The eclipsed conformation of ethane is more stable than staggered conformation even though the eclipsed conformation has torsional strain
• C. The staggered conformation of ethane is more stable than eclipsed conformation, because comparatively staggered conformation has no torsional strain
• D. The staggered conformation of ethane is less stable than eclipsed conformation, because staggered conformation has torsional strain

Answer 1

The correct option is C

The staggered conformation of ethane is more stable than eclipsed conformation, because comparatively staggered conformation has no torsional strain

Torsional strain in molecules is a result of repulsion between the groups. As shown above, they are closer in the eclipsed form and thus experience greater repulsion.