Chapter 10, Problem 10.18P

(a)

Interpretation Introduction

Interpretation:

Lewis structure for a resonance form of each ion of ${\text{AsO}}_4^{3-}$ with the lowest possible formal charges is to be drawn. Also, the oxidation number of the atom is to be determined.

Concept introduction:

The steps to draw the Lewis structure of the molecule are as follows:

Step 1: Find the central atom and place the other atoms around it. The atom in a compound which has the lowest group number or lowest electronegativity considered as the central atom.

Step 2: Calculate the total number of valence electrons.

Step 3: Connect the other atoms around the central atoms to the central atom with a single bond and lower the value of valence electrons by 2 of every single bond.

Step 4: Allocate the remaining electrons in pairs so that each atom can get 8 electrons.

Formula to calculate the formal charge of the atom is as follows:

  $\text{Formal}\text{charge}=\left(\begin{array}{l}\text{number}\text{of}\\ \text{valence}\\ \text{electrons}\end{array}\right)-\left(\left(\begin{array}{l}\text{number}\text{of}\\ \text{non-bonding}\\ \text{electrons}\end{array}\right)+\left(\frac{1}{2}\right)\left(\begin{array}{l}\text{number}\text{of}\\ \text{bonding}\\ \text{electrons}\end{array}\right)\right)$        (1)

The formula to calculate the oxidation number of an atom is as follows:

  $\text{Oxidation}\text{number}=\left(\begin{array}{l}\text{number}\text{of}\\ \text{valence}\\ \text{electrons}\end{array}\right)-\left(\left(\begin{array}{l}\text{number}\text{of}\\ \text{non-bonding}\\ \text{electrons}\end{array}\right)+\left(\begin{array}{l}\text{number}\text{of}\\ \text{bonding}\\ \text{electrons}\end{array}\right)\right)$        (2)

(b)

Interpretation Introduction

Interpretation:

Lewis structure for a resonance form of each ion of ${\text{ClO}}_2^{-}$ with the lowest possible formal charges is to be drawn. Also, oxidation number of the atom is to be determined.

Concept introduction:

The steps to draw the Lewis structure of the molecule are as follows:

Step 1: Find the central atom and place the other atoms around it. The atom in a compound which has the lowest group number or lowest electronegativity considered as the central atom.

Step 2: Calculate the total number of valence electrons.

Step 3: Connect the other atoms around the central atoms to the central atom with a single bond and lower the value of valence electrons by 2 of every single bond.

Step 4: Allocate the remaining electrons in pairs so that each atom can get 8 electrons.

Formula to calculate the formal charge of the atom is as follows:

  $\text{Formal}\text{charge}=\left(\begin{array}{l}\text{number}\text{of}\\ \text{valence}\\ \text{electrons}\end{array}\right)-\left(\left(\begin{array}{l}\text{number}\text{of}\\ \text{non-bonding}\\ \text{electrons}\end{array}\right)+\left(\frac{1}{2}\right)\left(\begin{array}{l}\text{number}\text{of}\\ \text{bonding}\\ \text{electrons}\end{array}\right)\right)$        (1)

The formula to calculate the oxidation number of atom is as follows:

  $\text{Oxidation}\text{number}=\left(\begin{array}{l}\text{number}\text{of}\\ \text{valence}\\ \text{electrons}\end{array}\right)-\left(\left(\begin{array}{l}\text{number}\text{of}\\ \text{non-bonding}\\ \text{electrons}\end{array}\right)+\left(\begin{array}{l}\text{number}\text{of}\\ \text{bonding}\\ \text{electrons}\end{array}\right)\right)$        (2)