Question #e9eb6

1 Answer
Sep 19, 2017

Answer:

Diborane is nonpolar because it is a symmetrical molecule.

Explanation:

The structure of diborane is

Diborane

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.