Final answer:
The shape of PCl3 is trigonal bipyramidal and the appropriate hybridization of phosphorus in this molecule is sp³d.
Step-by-step explanation:
In a molecule of phosphorus pentachloride (PCl5), there are five P-Cl bonds, resulting in five pairs of valence electrons around the phosphorus atom. This leads to a trigonal bipyramidal shape for PCl5. To understand the hybridization of phosphorus in this molecule, we consider the number of electron groups around the central atom. In this case, there are five electron groups, so the appropriate hybridization is sp³d.