The most stable conformation for $n$-butane is

If the $C_2$ carbon in the given Newman projection is rotated by $120^{\circ}$ in the anticlockwise direction,what will be the resulting conformation of the $C_2-C_3$ bond?

Which of the following conformations of butane is the least stable?

Select the correct option about conformations of ethane.

The dihedral angle in the staggered form of the Newman projection of $1,1,1-$trichloroethane is $60^{\circ}$. (Round off to the nearest integer)

Define torsional strain.