Because the polarity of a molecule affects its physical properties, you need to know whether a molecule is polar or nonpolar when predicting how it might interact with other molecules. Predict whether

(a) A boron trifluoride molecule, BF₃, and 

(b) An ozone molecule, O₃, are polar.

ANTICIPATE The bonds in BF₃ are very polar, but the bonds in O₃ are not, so you might expect BF₃ to be polar and O₃ to be nonpolar. However, the shape of a molecule determines the polarity of the molecule, so the shapes must be identified before you can make a prediction.

PLAN In each case, predict the shape of the molecule by using the VSEPR model and then decide whether the dipole moments associated with the bonds cancel as a result of the symmetry of the molecule. If necessary, refer to Fig. 2E.7.

Transcribed Image Text:

VSEPR formula AX₂ AX₂E AX₂E₂ AX₂E, Nonpolar CO₂ XeF₂, I₂ Polar N₂O SO₂, H₂O BrIF- VSEPR formula AX4 AX₂E AX₂E₂ Nonpolar CH₂ XeF Polar CH₂Cl SFA