Question

what is confirmation of ethane​

Answer 1

Ethane shows up confirmational isomerism.

Ethane mainly shows three types of confirmational isomerism.
1) Staggered form where the dihedral angle between each of the alternate C-H bond is 60° when viewed from Newmann or Saw horse projections.
2) Ellipsed form in which the dihedral angle is zero
3) Skew form where the dihedral angle is anywhere between 0 to 60° so there can be infinitely many possible intermediate skew confirmations.
However the most stable and existable conformation of ethane is of staggered form because of almost minimum steric repulsion.

Answer 2

It is called as " staggered", conformation,in which all of C-H bonds on the front of carbon are positioned at dihedral angle of 60° relative to the C-H bonds on the back carbon .....Another 60° rotation returns to the molecule to a second eclipsed conformation