Question

What are the Lewis structures for the two allotropic forms of oxygen? How can the Para magnetism of ${\mathbf{\text{O}}}_{\mathbf{\text{2}}}$be explained using the molecular orbital model? What are the molecular structure and the bond angles in ozone?

Short answer

The Lewis structures for the two allotropic forms of oxygen is –

Using molecular orbital model, it can be seen that${\text{O}}_{\text{2}}$ has a double bond which results in it being para magnetic.

The ozone molecule is angular, forming a shape structure with a bond angle of$117°$ .

Step-by-step solution

Concept Introduction

Para magnetism is a property of a small number of materials that is weakly attracted to a magnetic field (as opposed to ferromagnetism, which results in permanent magnetic materials, or diamagnetism, which is present in all materials).

Lewis Structure

Oxygen has two allotropes, dioxygen and ozone.

Dioxygen has a triplet ground state and oxidizes hydrocarbons by a radical chain mechanism.

Reaction with an excited state molecule can produce a fairly long-lived singlet state that can react as an electrophile.

Ozone is an unstable and highly aggressive oxidizing agent

Lewis structures of dioxygen and ozone are shown in the figure below.

Therefore, the Lewis structure is obtained.

Para magnetism in Oxygen and bond angles in Ozone

The molecular orbital description of${\text{O}}_{\text{2}}$implies the existence of a double bond.

However, the outermost two electrons occupy different antibonding aorbital with parallel spins. As a result, the moleculeis paramagnetic.

The${\text{O}}_3$molecule is angular, in accord with the VSEPR modeland has bond angle$117°$$117°$. Which is slightly less than the predicted$120°$ trigonal planar bond angle.The outermost two electrons occupy different antibondingorbitals with parallel spins.

Therefore, oxygen has double bond which explains para magnetism and bond angle in ozone is $117°$.