Answer:
<em>Figure Attached</em>
Explanation:
a. To draw a Newman projection we draw a circle for the rare carbon and and put a dot in center of circle for the front carbon. For a dihedral angle of 180° we put the respective groups opposite to each other making an angle of 180°.
b. For a dihedral angle of 60° Just rotate the conformation of dihedral angle 180° to anti clock wise up to 120°.
For a dihedral angle of 300° Just rotate the conformation of dihedral angle 180° to clock wise up to 120°.
c. The lowest energy conformation is the conformation having dihedral angle 180°. Because in this conformation the bulky groups are anti to each other.
d. Conformations having dihedral angle 60° and 300° are reflection of each other.
