Chapter 12, Problem 59A

(a)

Interpretation Introduction

Interpretation:

The molecular structure of given molecule $\mathrm{S}{\mathrm{O}}_2$ is to be predicted.

Concept introduction:

VSEPR theory helps to draw the molecular shape as:

Total number of valence electron pairs	Number of bond pairs	Number of lone pairs	Geometry and shape
2	2	0	linear
3	3	0	Trigonal planar
	2	1	bent
4	4	0	Tetrahedral
	3	1	Pyramidal
	2	2	Bent

The multiple bonds are considered as single bond for determining the molecular structure.

Answer to Problem 59A

The molecular structure of $\mathrm{S}{\mathrm{O}}_2$ is bent.

Explanation of Solution

Lewis structure of $\mathrm{S}{\mathrm{O}}_2$ is:

  

It shows, there are 2 bond pairs and 2 lone-pairs around sulphur atom. Therefore, by VSEPR theory its shape is bent.

(b)

Interpretation Introduction

Interpretation:

The molecular structure of given molecule $\mathrm{S}{\mathrm{O}}_3$ is to be predicted.

Concept introduction:

VSEPR theory helps to draw the molecular shape as:

Total number of valence electron pairs	Number of bond pairs	Number of lone pairs	Geometry and shape
2	2	0	linear
3	3	0	Trigonal planar
	2	1	bent
4	4	0	Tetrahedral
	3	1	Pyramidal
	2	2	Bent

The multiple bonds are considered as single bond for determining the molecular structure.

Answer to Problem 59A

The molecular structure of $\mathrm{S}{\mathrm{O}}_3$ is planar.

Explanation of Solution

Lewis structure of $\mathrm{S}{\mathrm{O}}_3$ is:

  

It shows, there are 3 bond pairs and no lone pairs around carbon atom. Therefore, by VSEPR theory its shape is trigonal planar.

(c)

Interpretation Introduction

Interpretation:

The molecular structure of given molecule is to be predicted.

Concept introduction:

VSEPR theory helps to draw the molecular shape as:

Total number of valence electron pairs	Number of bond pairs	Number of lone pairs	Geometry and shape
2	2	0	linear
3	3	0	Trigonal planar
	2	1	bent
4	4	0	Tetrahedral
	3	1	Pyramidal
	2	2	Bent

The multiple bonds are considered as single bond for determining the molecular structure.

Answer to Problem 59A

The molecular structure of $\mathrm{H}\mathrm{C}{\mathrm{O}}_3{}^{-}$ is trigonal planar.

Explanation of Solution

Lewis structure of $\mathrm{H}\mathrm{C}{\mathrm{O}}_3{}^{-}$ is:

  

It shows, there are 3 bond pairs and no lone-pair around carbon atom. Therefore, by VSEPR theory its shape is trigonal planar.

(d)

Interpretation Introduction

Interpretation:

The molecular structure of given molecule HCN is to be predicted.

Concept introduction:

VSEPR theory helps to draw the molecular shape as:

Total number of valence electron pairs	Number of bond pairs	Number of lone pairs	Geometry and shape
2	2	0	linear
3	3	0	Trigonal planar
	2	1	bent
4	4	0	Tetrahedral
	3	1	Pyramidal
	2	2	Bent

The multiple bonds are considered as single bond for determining the molecular structure.

Answer to Problem 59A

The molecular structure of $\mathrm{H}\mathrm{C}\mathrm{N}$ is linear.

Explanation of Solution

Lewis structure of $\mathrm{H}\mathrm{C}\mathrm{N}$ is:

  

It shows, there are 2 bond pairs and no lone pairs around carbon atom. Therefore, by VSEPR theory its shape is linear.