Chapter 2, Problem 2C.18E

(a)

Interpretation Introduction

Interpretation:

Dominant resonance hybrid structure among below two Lewis structures have to be determined.

Concept Introduction:

Resonance hybrid structures are set of two or more Lewis structures that illustrate electronic bonding through fractional bonds or fractional charges. Dominant resonance structure possesses the rules as follows:

1. Complete octet of each atom.

2. Smallest number of formal charges.

3. Most electronegative atom should possess negative charge and most electropositive atom should possess positive charge.

The formal charge is the charge assigned on each atom irrespective of its electronegativity so that electrons are equally shared between the atoms. The formal charge on each atom in the Lewis structure can be calculated from the equation written as follows:

  $\text{Formal charge}=\left[V-L-\frac{1}{2}B\right]$

Here,

$V$ denotes valence electrons in free atom.

$L$ denotes electrons present as lone pairs.

$B$ denotes electrons present as bond pairs.

(b)

Interpretation Introduction

Interpretation:

Dominant resonance hybrid structure among below two Lewis structures have to be determined.

Concept Introduction:

Refer to part (a).