Question
Both BF3 and CH4 have zero dipole moment. Explain.
Solution
BF3 has zero dipole moment even though B and F have different electronegativities and each of the B – F bond is polar and has the same dipole moment. This is because, in the molecules of BF3, the fluorine atoms lie at the vertices of an equilateral triangle while boron atom lies at its centre. As a result, the individual dipole moments give a net sum of zero.
On the other hand, methane molecule has zero dipole moment because the individual dipole moments cancel out because of the symmetrical tetrahedral shape of the molecule.
On the other hand, methane molecule has zero dipole moment because the individual dipole moments cancel out because of the symmetrical tetrahedral shape of the molecule.
