Four neutral molecules—CO2, SO2, BF3, and NF3—are commonly cited when discussing whether molecular shape causes cancellation (or reinforcement) of individual bond dipoles.
Electronegativity values (Pauling scale) are provided for reference:
C = 2.5, O = 3.5, S = 2.6, B = 2.0, F = 4.0, N = 3.0.
Answer the following questions about these four molecules.
(a) For each molecule, draw a complete Lewis electron-dot diagram and state the electron-pair geometry and molecular geometry around the central atom.
(b) For each molecule, indicate whether it possesses a net molecular dipole moment. Clearly justify each decision in terms of both bond polarity and three-dimensional symmetry.
(c) Among the four molecules, rank them from the smallest to the largest expected magnitude of overall dipole moment. Provide a concise explanation that links the ranking to the spatial arrangement of bond dipoles.