Question

The correct statement(s) regarding diborane $\left(B_2{H}_6\right)$ is/are:

• A. Maximum six hydrogen atoms can lie in a plane.
• B. Maximum six atoms can lie in a plane.
• C. Bridging $H-B-H$ bond is stronger than terminal $B-H$ bond.
• D. Terminal $H-B-H$ bond angle is greater than bridging $H-B-H$ bond angle.

Answer 1

Answer: (B), (C), (D)

The correct options are
B Maximum six atoms can lie in a plane.
C Bridging $H-B-H$ bond is stronger than terminal $B-H$ bond.
D Terminal $H-B-H$ bond angle is greater than bridging $H-B-H$ bond angle.


We can draw one plane that passes through both the boron atoms and all four bridging hydrogen atoms. This means there can be a maximum of six atoms on that plane.
As we can see in the figure, the bridging $B-H$ bond length is $131pm$ which is larger than the terminal $119pm$. Also visible is the terminal $H-B-H$ angle at ${120}^o$ which is greater than the bridging ${97}^o$.