Question

In diborane $ (B_2H_6) $ there are

• A. three $ 3c - 2e^- $ bonds and three $ 2c - 2e^- $ bonds
• B. four $ 3c - 2e^- $ bonds and two $ 2c - 2e^- $ bonds
• C. two $ 3c - 2e^- $ bonds and four $ 2c - 2e^- $ bonds
• D. None of the above

Answer 1

Answer: (C)

The structure of diborane is shown below

$\bullet$ Boron electron
$\bullet$ Hydrogen electron
The four terminal $B—H$ bonds are regular bonds $(2c - 2e^-$ bonds) but the two bridge $B - H$ bonds are different and formed only by sharing of two electrons ($3c - 2e^-$ bonds).