Oxidising and reducing agents

Table of Contents

1. Oxidising agents and reducing agents
2. Redox reactions
   1. Oxidation numbers
3. Oxidising agents and reducing agents
   1. Oxidants and reductants
   2. Common oxidants and reductants
4. Half-equations
   1. Writing half-equations
   2. Combining half-equations
5. Reduction potentials
   1. Source of reduction potentials
   2. Using standard electrode potentials
   3. Predicting reaction tendencies
6. Redox reactions in action

1. Additional resources:
   1. Glossary
   2. Print content

Redox reactions

Oxidation can be described as the reaction with oxygen. Respiration is an example of an oxidation reaction. The reaction is shown below.

C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O

From your earlier studies, you should know some other definitions of oxidation and reduction. Write down any definitions that you know, discussing your ideas with others or your teacher if you have the opportunity. Click the link below to reveal more.

Oxidation and reduction

You have seen that oxidation and reduction are the reverse of each other, and one cannot occur without the other. In a redox reaction there is always a substance being oxidised and a substance being reduced. The best way to investigate redox reactions at this stage is by considering the transfer of electrons.

 

Half-equations

You should recall that we can use half-equations to show the oxidation and reduction processes occurring in redox reactions. Write half-equations in your notes for the reactions in the above activity that were redox reactions.

Once you have done this, click the link below.

Half equations

Sometimes it is helpful to use the concept of oxidation number to determine whether a redox reaction is occurring, and to identify what is being oxidised and reduced in the process. The next section will revise the idea of oxidation number and use oxidation numbers to reveal the changes occurring in more redox reactions.