What are the bond angles in the following molecular model of PF5?
The correct answer and explanation is :
Phosphorus pentafluoride (PF₅) exhibits a trigonal bipyramidal molecular geometry, which influences its bond angles. In this configuration, three fluorine atoms occupy equatorial positions, forming a plane around the phosphorus atom, while the remaining two fluorine atoms occupy axial positions above and below this plane. This arrangement results in two distinct bond angles:
- Equatorial-Equatorial Bond Angle: The angle between two fluorine atoms in equatorial positions is approximately 120°.
- Axial-Equatorial Bond Angle: The angle between a fluorine atom in an axial position and one in an equatorial position is approximately 90°.
These bond angles arise due to the electron pair repulsion described by Valence Shell Electron Pair Repulsion (VSEPR) theory, which predicts the spatial arrangement of atoms in a molecule to minimize electron-electron repulsion.