Chapter 3, Problem 3.126P

Interpretation Introduction

(a)

Interpretation:

Using VSEPR Theory, the geometry of each central atom present in given structure of Androstenedione is to be identified.

Concept Introduction:

Bond angles in the molecules can be predicted by using valence shell electron pair repulsion (VSEPR) model. According to this model, the valence electrons of an atom are involved in the formation of single, double or triple bond. The valence electrons can also be unshared and exist as lone pair on atoms. The combination forms a negatively charged region of electron density around a nucleus. Since, like charges do not attract, the region of electron density around a nucleus spread out so that each atom is as far away from each other at different angles.

Interpretation Introduction

(b)

Interpretation:

Using VSEPR theory, the various relative bond angles associated with each central atom of the Androstenedione molecule is to be determined.

Concept Introduction:

Bond angles in the molecules can be predicted by using valence shell electron pair repulsion (VSEPR) model. According to this model, the valence electrons of an atom are involved in the formation of single, double or triple bond. The valence electrons can also be unshared and exist as lone pair on atoms. The combination forms a negatively charged region of electron density around a nucleus. Since, like charges do not attract, the region of electron density around a nucleus spread out so that each atom is as far away from each other at different angles.

1. Each carbon atom having all single bonds having tetrahedral geometry has bond angle ${109.5}^{{\rm O}}$

2. Each carbon atom having double bond having trigonal planner geometry has bond angle 120(.

Interpretation Introduction

(c)

Interpretation:

The most polar bond in androstenedione is to be predicted.

Concept Introduction:

A molecule is polar if it has polar bonds and the centers of its partial positive and partial negative charge do not coincide.

Interpretation Introduction

(d)

Interpretation:

Observing the bonds of Androstenedione molecule, it should be determined whether Androstenedione is polar or nonpolar.

Concept Introduction:

A molecule is polar if it has polar bonds and if the centers of partial positive charge and partial negative charge lie at different places with in the molecule.