Question

A molecule with the formula\({\rm{A}}{{\rm{B}}_{\rm{2}}}\), 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 for each shape.

Short answer

A molecule with molecular formula \({\rm{A}}{{\rm{B}}_{\rm{2}}}\) can have linear shape for example\({\rm{C}}{{\rm{O}}_{\rm{2}}}\), bent (\({\rm{12}}{{\rm{0}}^{\rm{^\circ }}}\)) shape for example \({\rm{S}}{{\rm{O}}_{\rm{2}}}\) and tetrahedral electron pair geometry \(\left( {{\rm{10}}{{\rm{9}}^{\rm{^\circ }}}} \right)\)shape for example \({{\rm{H}}_{\rm{2}}}{\rm{O}}\)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. In total, there are five bonds in the trigonal bipyramidal geometry.

Sketch and name the three different shapes that this molecule

One A atom and two B atoms make up a molecule with the molecular formula\({\rm{A}}{{\rm{B}}_{\rm{2}}}\). There are two atoms that are bonded together. As a result, this molecule can have three molecular shapes: linear electron pair geometry and linear shape when there are only two electron density regions and no lone pair on the central A-atom, trigonal planar electron pair geometry and bent\({\rm{12}}{{\rm{0}}^{\rm{^\circ }}}\)shape when there are two bond pairs on the central A-atom, and trigonal planar electron pair geometry and bent\({\rm{12}}{{\rm{0}}^{\rm{^\circ }}}\)shape when there are two bond pairs on the central A-atom.

Therefore, the required shapes are below: