Chem geometry questions

Question

1)what condition must be met if a molecule with polar bonds is non-polar?

2)what geometries will give non-polar molecules for AB2, AB3 and AB4 geometries?

Answer 1

1) The molecule must be symmetrical, to cancel out the polarities of the individual bonds (vector sum of bond polarities = 0).

2) AB2 must be linear to be non-polar (example: CO2)

AB3 must be trigonal planar to be non-polar (example: BH3)

AB4 must be tetrahedral to be non-polar (example: CH4)