Staggered configuration is more stable as compared to eclipsed, as there is less C – H bond pair repulsion and the atoms are at maximum distance away from each other. The C – H bond pair repulsion leads to torsional strain which is maximum when ethane is in eclipsed form. Also from the diagram it is evident that the electron cloud repulsion is more in eclipsed form than is staggered arrangement. Ethane, at all time, can exist in both of these forms as the energy to convert one form into another isonly 12.5 kJ mol^-, which can be made available at room temperature.