Question

Which of the following molecules would you expect to have a dipole moment of zero? To answer parts g and h, you may need to review the Problem Solving Strategy on p. 39.

Short answer

BeCl₂, BF₃, have zero dipole moment.

Step-by-step solution

Finding out the electronic configuration.

BeCl₂

Electronic configuration: 1s²2s²2p⁰

BF₃

Electronic configuration of Boron: 1s²2s²2p¹

finding out the dipole moment.

BeCl₂

BeCl₂is sp hybridised thus has linear structure, bond angle is 180.

Cl-Be-Cl .As a result the dipole moments on both sides cancel each other and the net dipole moment is zero.

BF₃

BF₃ has sp² hybridisation, thus is trigonal planar in shape.

The resultant dipole moment of any two bonds is equal and opposite to the dipole moment of the third bond. Thus cancels each other and gives a zero dipole moment.

The resultant dipole moment of any two bonds is equal and opposite to the dipole moment of the third bond. Thus cancels each other and gives a zero dipole moment.