Chapter 7: Q108E (page 405)

A molecule with the formula\({\rm{A}}{{\rm{B}}_{\rm{3}}}\), in which A and B represent different atoms, could have one of three different shapes. Sketch and name the three different shapes that this molecule might have. Give an example of a molecule or ion that has each shape.

Short Answer

Expert verified

A molecule with molecular formula \({\rm{A}}{{\rm{B}}_{\rm{3}}}\) can have T-shape for example \({\rm{IC}}{{\rm{l}}_{\rm{3}}}\), trigonal planar for example \({\rm{B}}{{\rm{F}}_{\rm{3}}}\)and trigonal pyramidal for example \({\rm{N}}{{\rm{H}}_{\rm{3}}}\) shapes shown as follows:

Step by step solution

Definition of Concept

There are two types of bonds in trigonal bipyramidal structures: axial bonds and equatorial bonds. So, there are five bonds in the trigonal bipyramidal geometry.

Sketch and name the three different shapes that this molecule

A molecule with the molecular formula\({\rm{A}}{{\rm{B}}_{\rm{3}}}\)is made up of one A atom and two B atoms. There are three atoms that are bonded together. As a result, this molecule can have three molecular shapes: when there are only three bond pairs and no lone pair on the central A-atom, it has trigonal planar electron pair geometry and trigonal pyramidal shape; when there are three bond pairs and one lone pair on the central A-atom, it has tetrahedral electron pair geometry and trigonal pyramidal shape; and when there are three bond pairs and two lone pairs on the central A.

Therefore, the required shapes are below: