Question 6.18: Determine whether a molecule of OF2 is polar or nonpolar.

STEP 1   Determine if the bonds are polar covalent or nonpolar covalent. From Figure 6.6, F and O have an electronegativity difference of 0.5 (4.0 – 3.5 = 0.5), which makes the O — F bonds polar covalent.

STEP 2   If the bonds are polar covalent, draw the Lewis structure and determine if the dipoles cancel. The Lewis structure for OF_{2} has four electron groups and two bonded atoms. The molecule has a bent shape in which the dipoles of the O — F bonds do not cancel. The OF_{2} molecule would be polar.