Question

In the trigonal bipyramidal, where are the lone pair electrons localized in order to minimize repulsion forces

A) Equatorial position
B) Axial position
C) At the center
D) Spread evenly across all positions

Answer 1

A) Equatorial position

In trigonal bipyramidal geometry, to minimize repulsion forces, lone pair electrons are placed in the equatorial positions which offer a greater angle of 120° as opposed to the less spacious 90° axial positions.

Step-by-step explanation:

In the trigonal bipyramidal arrangement, the lone pair electrons are localized in a way to minimize repulsion forces.

According to Valence Shell Electron Pair Repulsion (VSEPR) theory, when we have five electron groups around the central atom, consisting of two bonding pairs and three lone pairs, the lone pairs should be placed in the positions that will reduce electron-pair repulsion.

We encounter two distinct positions in trigonal bipyramidal geometry: the axial position and the equatorial position. The equatorial positions have a more open angle of 120°, offering more space, whereas the axial positions are surrounded by 90° angles and are less spacious.

Based on these arrangements, to minimize lone pair repulsions, the lone pairs are typically located in equatorial positions, which provide a greater distance between the electron pairs and therefore minimize the repulsion forces.