Question

What are compound radicals? Give examples of a few radicals, along with their valencies. Also mention some compounds containing compound radicals. Give the valencies of the parts that make up the compound.

Answer 1

A group of atoms that behave as a single unit in many different compounds are known as radicals. A compound radical has unpaired valence electrons.

Complete step by step answer:
The chemical species that contains a group of atoms which behave as a single unit in different compounds and have unpaired valence electrons is known as a compound radical.
The breaking of a single covalent bond to leave an unpaired electron on both the species that are bonded by it lead to the formation of radicals.
The compound radicals can be of two types based on the charge they carry i.e. positive and negative.
The examples of compound radicals are as follows:
Nitrate $\left( {{\text{NO}}_3^ - } \right)$: The charge on the radical is $- 1$. Thus, the valency of nitrate radical is 1.
Carbonate $\left( {{\text{CO}}_3^{2 - }} \right)$: The charge on the radical is $- 2$. Thus, the valency of carbonate radical is 2.
Ammonium $\left( {{\text{NH}}_4^ + } \right)$: The charge on the radical is $+ 1$. Thus, the valency of ammonium radical is 1.
Sulphate $\left( {{\text{SO}}_4^{2 - }} \right)$: The charge on the radical is $- 2$. Thus, the valency of sulphate radical is 2.
The compounds containing compound radicals give out compound radicals in their aqueous solutions. Examples of compounds containing compound radicals are as follows:
Sulphuric acid $\left( {{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}} \right)$: ${{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}$ has compound radical ${\text{SO}}_4^{2 - }$.
Nitric acid $\left( {{\text{HN}}{{\text{O}}_{\text{3}}}} \right)$: ${\text{HN}}{{\text{O}}_{\text{3}}}$ has compound radical ${\text{NO}}_3^ -$.
Ammonium chloride $\left( {{\text{N}}{{\text{H}}_4}{\text{Cl}}} \right)$: ${\text{N}}{{\text{H}}_4}{\text{Cl}}$ has compound radical ${\text{NH}}_4^ +$.
Consider nitric acid $\left( {{\text{HN}}{{\text{O}}_{\text{3}}}} \right)$. Nitric acid in its aqueous solution gives ${{\text{H}}^ + }$ and compound radical ${\text{NO}}_3^ -$.
In the compound radical ${\text{NO}}_3^ -$, we have to determine the valency of nitrogen and oxygen. This is known as the valency of parts.
In ${\text{NO}}_3^ -$, the valency of nitrogen is 1 and the valency of oxygen is 2.

Note:
Radicals can be generated by various methods like heat, electrolysis, ionizing radiation, electrical discharge. The most common method of radical generation is redox reaction.