Redox Reactions - Oxidising Agents

Defining an Oxidising Agent

In a chemical reaction, an oxidising agent is a substance that causes oxidation to occur in another substance. Crucially, the oxidizing agent itself undergoes reduction in the process. This is a fundamental concept in redox chemistry.

Oxidation and Reduction

To understand oxidizing agents, it's important to remember oxidation and reduction. Oxidation is the loss of electrons, and reduction is the gain of electrons. Oxidising agents are the substances that accept electrons, thereby causing oxidation in another species.

Identifying Oxidising Agents

Here's a summary of key characteristics:

• Accepts electrons: An oxidizing agent has a high affinity for electrons.
• Undergoes reduction: When it accepts electrons, the oxidizing agent itself is reduced.
• Causes oxidation: It facilitates the loss of electrons in another substance.

Examples of Common Oxidising Agents

Some common examples of oxidizing agents include:

• Oxygen ($O_2$)
• Chlorine ($Cl_2$)
• Manganese(VII) ion ($MnO_4^−$)
• Chromium(VI) ion ($CrO_4^{2−}$ or $CrO_3$)
• Potassium permanganate ($KMnO_4$)
• Hydrogen peroxide ($H_2O_2$)

Oxidising Agents in Redox Equations

In redox equations, oxidizing agents are typically on the left-hand side of the equation, as they are the species being reduced. The oxidation state of the oxidizing agent will decrease during the reaction.

Table Summary

Property	Description
Definition	A substance that causes oxidation in another substance and is itself reduced.
Role in Redox	Accepts electrons, causing oxidation of another species.
Typical Location in Equations	Usually on the reactant (left) side, being reduced.
Examples	$O_2$, $Cl_2$, $MnO_4^−$, $CrO_4^{2−}$, $KMnO_4$, $H_2O_2$