A Mercury(II) chloride dissolves in water to give poorly conducting solutions, indicating that the compound is largely nonionized in solution—it dissolves as HgCl2 molecules. Describe the bonding of the HgCl2 molecule, using valence bond theory. b Phosphorus trichloride, PCl3, is a colorless liquid with a highly irritating vapor. Describe the bonding in the PCl3 molecule, using valence bond theory. Use hybrid orbitals.