ACS Chemistry Practice Exam 2025 – The All-in-One Guide to Exam Success!

The molecular geometry of a molecule with 5 electron domains, including 2 bonding pairs and 3 nonbonding pairs, is best described as T-shaped.

When determining the molecular geometry, it is essential to consider both the bonding and nonbonding electron pairs. In this scenario, with 5 electron domains, the arrangement of those domains is fundamentally trigonal bipyramidal, a geometry characterized by 2 positions in a plane and 3 extending above and below that plane.

However, since there are 3 nonbonding pairs, they will occupy the equatorial positions (the plane) due to their greater repulsive effect compared to bonding pairs. This forces the 2 bonding pairs into the axial positions of the trigonal bipyramidal structure. As a result, the overall shape of the molecule, taking into account the positions of the bonding pairs versus the nonbonding pairs, adopts a T shape. This arrangement effectively minimizes electron pair repulsion while allowing for the necessary angles between bonds.

While the options contained may point toward different shapes, recognizing that the basic arrangement starts as trigonal bipyramidal is key to understanding how the presence of 3 nonbonding sets alters the geometry to T-shaped.