Chapter 2, Problem 2F.1BST

(a)

Interpretation Introduction

Interpretation:

Number of $\sigma$- bonds and $\text{π}$- bonds in molecule ${\text{NH}}_3$ has to be determined.

Concept Introduction:

Valence Bond Theory gives information about the chemical bonding between two atoms in terms of atomic orbital.

Sigma bond commonly called single bond is formed by end to end overlap of two atomic orbital with no nodal plane along its internuclear axis.

Pi bond commonly called double bond contains one $\sigma$- bond and other $\text{π}$- bond with one nodal plane along its internuclear axis.

In general, according to VBT (Valence Bond Theory) single bond and double bond is defined as follows:

• Single bond contains $\sigma$- bond.
• Double bond contains $\sigma$- bond and a $\text{π}$- bond.
• Triple bond contains one $\sigma$- bond and two $\text{π}$-bonds.

(b)

Interpretation Introduction

Interpretation:

The number of $\sigma$- bonds and $\text{π}$- bonds in the molecule $\text{HCN}$ has to be determined.

Concept Introduction:

Refer to part (a).