Final answer:
The false statement about the BCl3 molecule is that the ClBCl bond angles are 109.5. The correct bond angles in a trigonal planar geometry like BCl3 are 120°.
Step-by-step explanation:
The boron chloride molecule (BCl3) has a trigonal-planar shape, meaning it has a planar molecular structure with 120° angles between the bonds. Given this information, the false statement about the boron chloride molecule is that c. The ClBCl bond angles are 109.5. In a trigonal planar geometry, the bond angles are 120°, not 109.5°, which is characteristic of a tetrahedral geometry.
The bonds in BCl3 are quite polar due to the difference in electronegativity between boron and chlorine. However, since the molecule is symmetrically arranged with three bonding pairs at equal angles around the central boron atom, the bond dipoles cancel out. This cancellation makes BCl3 a nonpolar molecule overall, even though it contains polar bonds.
The bond dipoles in BCl3 do exactly cancel due to the molecule's highly symmetrical trigonal planar structure, making statement b. true. The molecular symmetry means that BCl3 does not have a net dipole moment, thus supporting statement d. that BCl3 molecules are nonpolar.