Chapter 2, Problem 2.1P

Interpretation Introduction

Interpretation:

Molecular geometry and electron geometry about nitrogen atom in the acetone imine molecule is to be predicted.

Concept introduction:

Electron geometry and molecular geometry of molecules is determined by using Valence shell electron pair repulsion (VSEPR) theory. According to VSEPR theory, electron geometry describes the orientation of the electron groups about a particular atom, and molecular geometry describes the arrangement of atoms about a particular atom.

Number of electron pairs describes the electron and molecular geometry. If all the electron pairs are bonds, then molecular geometry is the same as electron geometry. Electron geometry is different from molecular geometry if some electron pairs are present as lone pairs.

Electron geometry and molecular geometry from the number of electron pairs are as follows:

Number of electron pairs	Number of Bonds	Number of Lone pair	Electron geometry	Molecular Geometry
2	2	0	Linear	Linear
3	3	0	Trigonal planar	Trigonal planer
3	2	1	Trigonal planar	Bent

Answer to Problem 2.1P

Electron geometry about N atom in acetone imine molecule geometry is trigonal planar and molecular geometry is bent.

Explanation of Solution

The given acetone imine molecule is

In acetone imine molecule, there are total three groups of electrons about N atom. There is one double bond, one single bond, and one lone pair around N atom, that is, all electron pairs are not involved in bond formation, and hence, molecular geometry and electron geometry are different.

There are total three electron groups, hence, the electron geometry about N atom is trigonal planar. The molecular geometry is bent.

Conclusion

Electron geometry and molecular geometry about N atom is predicted from the number of electron pairs present around the atom in the given molecule.