Given structures $I$ and $II$ are:

In $ethane$ and $cyclohexane$,which one of the following pairs of conformations are more stable?

The two structures $I$ and $II$ represent:

Statement $I$: Staggered conformation of ethane is more stable than the eclipsed conformation.
Statement $II$: The torsional strain in staggered conformation is more than in the eclipsed conformation.

The energy difference between the staggered and eclipsed conformations of ethane is

In the staggered conformation of $C_2H_6$,the dihedral angle between $H-C-C-H$ bonds is ....$^o$.