Chapter 10, Problem 10.37QP

For each of the following molecules, state the bond angle (or bond angles, as appropriate) that you would expect to see on the central atom based on the simple VSEPR model. Would you expect the actual bond angles to be greater or less than this?

1. a CCl₄
2. b SCl₂
3. c COCl₂
4. d AsH₃

Interpretation Introduction

Interpretation:

With the help of VSEPR theory, the expected bond angle(s) of given molecules on the central atom has to be stated.

Concept Introduction:

Valence bond theory: The VSEPR theory tells about the shapes of molecules and ions by taking the consideration that the outermost electron pairs are arranged about each atom so that the pairs of electrons are kept at a distance from one molecule to other, thereby minimizing the repulsion of electron-pair.

Steps to predict the geometry by VSEPR model:

1. 1) The electron dot formula is written from the molecular formula.
2. 2) The number of electron pairs including the bonding and non-bonding pairs around the central atom is determined from the electron dot formula.
3. 3) The arrangement of these electron pairs about the central atom is determined.
4. 4) The molecular geometry is determined from the directions of the bonding pairs or the arrangement.

To predict the bond angle of ${\text{CCl}}_{\text{4}}$

Answer to Problem 10.37QP

The bond angle of ${\text{CCl}}_{\text{4}}$ would be $\text{109°}$ , this would be the expected bond angle too.

Explanation of Solution

The geometry of ${\text{CCl}}_{\text{4}}$ is tetrahedral and with the help of VSEPR theory, the bond angle of ${\text{CCl}}_{\text{4}}$ would be $\text{109°}$ , this would be the expected bond angle too.

Interpretation Introduction

Interpretation:

With the help of VSEPR theory, the expected bond angle(s) of given molecules on the central atom has to be stated.

Concept Introduction:

Valence bond theory: The VSEPR theory tells about the shapes of molecules and ions by taking the consideration that the outermost electron pairs are arranged about each atom so that the pairs of electrons are kept at a distance from one molecule to other, thereby minimizing the repulsion of electron-pair.

Steps to predict the geometry by VSEPR model:

1. 1) The electron dot formula is written from the molecular formula.
2. 2) The number of electron pairs including the bonding and non-bonding pairs around the central atom is determined from the electron dot formula.
3. 3) The arrangement of these electron pairs about the central atom is determined.
4. 4) The molecular geometry is determined from the directions of the bonding pairs or the arrangement.

To predict the bond angle of ${\text{SCl}}_{\text{2}}$

Answer to Problem 10.37QP

The bond angle of ${\text{SCl}}_{\text{2}}$ would be $\text{109°}$, it could be expected that bond angle of $\text{Cl-S-Cl}$ would be less.

Explanation of Solution

The geometry of ${\text{SCl}}_{\text{2}}$ is bent and with the help of VSEPR theory, the bond angle of ${\text{SCl}}_{\text{2}}$ would be $\text{109°}$, it could be expected that bond angle of $\text{Cl-S-Cl}$ would be less.

Interpretation Introduction

Interpretation:

With the help of VSEPR theory, the expected bond angle(s) of given molecules on the central atom has to be stated.

Concept Introduction:

Valence bond theory: The VSEPR theory tells about the shapes of molecules and ions by taking the consideration that the outermost electron pairs are arranged about each atom so that the pairs of electrons are kept at a distance from one molecule to other, thereby minimizing the repulsion of electron-pair.

Steps to predict the geometry by VSEPR model:

1. 1) The electron dot formula is written from the molecular formula.
2. 2) The number of electron pairs including the bonding and non-bonding pairs around the central atom is determined from the electron dot formula.
3. 3) The arrangement of these electron pairs about the central atom is determined.
4. 4) The molecular geometry is determined from the directions of the bonding pairs or the arrangement.

To predict the bond angle of ${\text{COCl}}_{\text{2}}$

Answer to Problem 10.37QP

The bond angle of ${\text{COCl}}_{\text{2}}$ would be $\text{120°}$ , it could be expected that $\text{Cl-C-O}$ would be more than $\text{120°}$ and $\text{Cl-C-Cl}$ would be less than $\text{120°}$.

Explanation of Solution

The geometry of ${\text{COCl}}_{\text{2}}$ is trigonal planar and with the help of VSEPR theory, it could be expected that $\text{Cl-C-O}$ would be more than $\text{120°}$ and $\text{Cl-C-Cl}$ would be less than $\text{120°}$.

Interpretation Introduction

Interpretation:

With the help of VSEPR theory, the expected bond angle(s) of given molecules on the central atom has to be stated.

Concept Introduction:

Valence bond theory: The VSEPR theory tells about the shapes of molecules and ions by taking the consideration that the outermost electron pairs are arranged about each atom so that the pairs of electrons are kept at a distance from one molecule to other, thereby minimizing the repulsion of electron-pair.

Steps to predict the geometry by VSEPR model:

1. 1) The electron dot formula is written from the molecular formula.
2. 2) The number of electron pairs including the bonding and non-bonding pairs around the central atom is determined from the electron dot formula.
3. 3) The arrangement of these electron pairs about the central atom is determined.
4. 4) The molecular geometry is determined from the directions of the bonding pairs or the arrangement.

To predict the bond angle of ${\text{AsH}}_{\text{3}}$

Answer to Problem 10.37QP

The bond angle of ${\text{AsH}}_{\text{3}}$ would be $\text{109°}$, it could be expected that bond angle of $\text{H-As-H}$ would be less.

Explanation of Solution

The geometry of ${\text{AsH}}_{\text{3}}$ is trigonal pyramidal and with the help of VSEPR theory, the bond angle of ${\text{AsH}}_{\text{3}}$ would be $\text{109°}$, it could be expected that bond angle of $\text{H-As-H}$ would be less.