Determine the molecular geometry and sketch each molecule or ion using the bond conventions shown in “Representing Molecular Geometries on Paper” in Section 11.4. c. PCl5

Key Concepts

Molecular Geometry

Molecular geometry refers to the three-dimensional arrangement of atoms within a molecule. It is determined by the number of bonding pairs and lone pairs of electrons around the central atom, which influences the shape of the molecule. Common geometries include linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral.

VSEPR Theory

Valence Shell Electron Pair Repulsion (VSEPR) theory is a model used to predict the geometry of molecules based on the repulsion between electron pairs in the valence shell of the central atom. According to VSEPR, electron pairs will arrange themselves to minimize repulsion, leading to specific molecular shapes. This theory is essential for determining the geometry of molecules like PCl5.

Bonding and Lone Pairs

In molecular structures, bonding pairs are the pairs of electrons shared between atoms, while lone pairs are the non-bonding pairs of electrons that belong to a single atom. The presence of lone pairs can significantly affect the molecular geometry by altering bond angles and overall shape. For PCl5, the arrangement of five bonding pairs around phosphorus leads to a trigonal bipyramidal geometry.