Question

Question #e9eb6

Answer 1

Diborane is nonpolar because it is a symmetrical molecule.

Explanation:

The structure of diborane is

Two of the `"H"` atoms act as bridges between the `"B"` atoms.

Theoretical calculations show that the partial charges on each atom are:

• `"B" color(white)(mmmmll)= "+2.12"`
• `"Bridging H" = color(white)(ll)"-0.71"`
• `"Terminal H" = color(white)(l) "-0.70"`

Thus, there are fairly large `"B-H"` bond dipoles.

However, the diborane molecule is perfectly symmetrical.

Every `"B-H"` bond dipole that points in one direction has a counterpart that points in exactly the opposite direction.

Thus, all bond dipoles cancel and diborane is a nonpolar molecule.