Final answer:
Dipole moments occur in molecules that have polar bonds and are asymmetrically arranged. SF4, Cl₂CCBr2, CH3Cl, and H₂CO all have dipole moments due to their molecular geometry and the electronegativity differences between the bonded atoms.
Step-by-step explanation:
To determine which of the molecules have dipole moments, one must consider the molecular geometry and the difference in electronegativity between the atoms within the molecule. Molecules with polar bonds that are asymmetrically arranged will have dipole moments.
- (a) SF4 has a see-saw shape due to one lone pair on the sulfur atom, resulting in a net dipole moment.
- (b) CF4 is tetrahedral and symmetrical, meaning it has no net dipole moment.
- (c) Cl₂CCBr2 (dichlorodibromomethane) is a tetrahedral molecule, but because the Cl and Br atoms differ in electronegativity, it has a net dipole moment.
- (d) CH3Cl has a tetrahedral shape with the chlorine atom creating a polar bond, resulting in a dipole moment.
- (e) H₂CO (formaldehyde) has a trigonal planar molecular structure with a significant difference in electronegativity between the carbon and the oxygen, leading to a dipole moment.
From this analysis, we can see that molecules SF4, Cl₂CCBr2, CH3Cl, and H₂CO have dipole moments.