Among the three conformations of ethane, the order of stability follows the sequence

Options

A. Eclipsed gt gauche gt staggered
B. Eclipsed gt staggered gt gauche
C. Staggered gt gauche gt eclipsed
D. Gauche gt staggered gt eclipsed

Answer

C

Explanation

The eclipsed conformation is least stable because the hydrogens and bonding pairs of electrons on adjacent carbon atoms are as close to one another as possible. This causes maximum repulsion and least stability. Staggered conformation is most stable because of minimum repulsion. Gauche conformation lies between these two in stability. Thus, order of stability is
Staggered > gauche > eclipsed