Question

In which of the following structures the pair of starred carbon atom do not lie in the same plane

• A.
• B.
• C.
• D.

Answer 1

The correct option is

B

Double-bond C atoms are $s{p}^2$ hybridized.
As $s{p}^2$ hybridized C atoms are planar, they lie in one plane.
In this case, starred carbon which is present on the right side is attached to $s{p}^3$ hybridized carbon and other starred carbon which is present on the left side is attached to $s{p}^2$ hybridized carbon.
Hence both the starred carbon are not attached to $s{p}^2$ hybridized carbon, so do not lie on the same plane.