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

Reduction potentials

Up to this point, most of this topic has been revision and consolidation of concepts introduced in Stage 2 Chemistry. The use of reduction potentials is a new idea.

Have you wondered why some metals, such as potassium (K), react violently with water?

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However, some metals such as gold (Au) will not be affected by water.

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Likewise, why is fluorine (F₂) such a reactive gas that it will dissolve its way through a glass container?

These questions are answered by using reduction potentials. In this topic you will be using reduction potentials to predict whether or not reactions will occur. (This is called predicting reaction tendency.)

In later topics you will use them to explain the operation of electrochemical cells. The ability to use and explain reduction potentials is vital to an understanding of redox chemistry and electrochemistry.

The reduction potentials that you will be using are given on the Standard Reduction Potentials section of the data sheet.

The first question to ask is: where do these values come from? This question is dealt with in the next section.