Chapter 6, Problem 115QRT

Interpretation Introduction

Interpretation:

The Lewis structure of $C_2^{2-}(acetylide),N_3^{-}(azide)O_3^{-}(ozonide)$ and its best resonance form has to be determined using formal charge.

Concept Introduction:

Lewis structure is also known as Lewis dot diagrams or electron dot structures.  The bond between atoms and lone pairs of electrons that is present in the molecule.  Lewis structure represents each atom and their position in structure using the chemical symbol.  Excess electrons forms the lone pair are given by pair of dots, and are located next to the atom.

According to the concept of resonance, when a single Lewis structure cannot describe a molecule accurately, a number of structures with same energy, position of nuclei, bonding and non-bonding pair of electrons are taken as the canonical structures of the hybrid which describes the molecule accurately.

The formula for the formal charge can be written as

  $\text{Formal}\text{charge=}\text{Valence}\text{electrons-lone}\text{pair}\text{electrons}\text{-}\frac{\text{Bonding}\text{electrons}}{\text{2}}$