Question

For a molecule with the three electron groups or charge clouds where one of those electron groups or charge clouds is nonbonding, the molecular geometry is:

A) Tetrahedral
B) Linear
C) Bent
D) Trigonal planar

Answer 1

Molecules with three electron groups, where one is nonbonding, adopt a bent or V-shaped molecular geometry. This occurs because the lone pair occupies more space, forcing the bonded atoms to come closer and resulting in a geometry that resembles a trigonal planar shape with a missing vertex.

Step-by-step explanation:

For a molecule with three electron groups, one of which is nonbonding, the molecule adopts a configuration that maximizes the separation of these electron groups. This configuration results in a trigonal planar arrangement with the three groups positioned at the corners of an equilateral triangle, each 120° apart. However, when one of these groups is a nonbonding pair of electrons (a lone pair), the molecular geometry changes. The nonbonding electron pair occupies more space than bonding pairs, pushing the bonded atoms closer together and resulting in a bent or V-shaped molecular geometry, which can be considered as a trigonal planar arrangement with a 'missing' vertex.

An example of a molecule with a trigonal planar electron-pair geometry is BF3, where each boron-fluoride bond represents a region of electron density. However, for molecules such as SO2, where there is one lone pair and two bonding pairs, the resulting geometry is bent due to the lone pair taking up more space.