Chapter 8.2, Problem 20LC

(a)

Interpretation Introduction

Interpretation: The electron dot structure for ${\text{H}}_{\text{2}}\text{S}$ molecule needs to be drawn.

Concept Introduction: An electron dot structure represents the arrangement of total valence electrons in a molecule. Here, electrons are represented as dots in pairs to show the lone pairs as well as the bond pairs.

Explanation of Solution

The given molecule is ${\text{H}}_{\text{2}}\text{S}$ . Here, the number of valence electrons in H and S atoms is 1 and 6 respectively. The total number of valence electrons will be:

  $\begin{array}{l}2\left(1\right)+6=2+6\\ =8\end{array}$

The electron dot structure can be represented as follows:

  

From the above structure, it is clear that there are 2 bonding pairs of electrons and 2 lone pairs of electrons.

(b)

Interpretation Introduction

Interpretation: The electron dot structure for ${\text{PH}}_3$ molecule needs to be drawn.

Concept Introduction: An electron dot structure represents the arrangement of total valence electrons in a molecule. Here, electrons are represented as dots in pairs to show the lone pairs as well as the bond pairs.

Explanation of Solution

The given molecule is ${\text{PH}}_3$ . Here, number of valence electrons in P and H atom is 5 and 1 respectively. Thus, total number of valence electrons in the molecule is:

  $5+3\left(1\right)=8$

The distribution of electrons can be represented by electron dot structure as follows:

  

(c)

Interpretation Introduction

Interpretation: The electron dot structure for the ClF molecule needs to be drawn.

Concept Introduction: An electron dot structure represents the arrangement of total valence electrons in a molecule. Here, electrons are represented as dots in pairs to show the lone pairs as well as the bond pairs.

Explanation of Solution

The given molecule is ClF. Here, both Cl and F have 7 valence electrons. The total number of valence electrons will be 14. The electron dot structure can be represented as follows:

  

From the above structure, it is clear that there are 1 bonding pair and 6 lone pairs of electrons (non-bonding pairs).