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Chemistry » Chemistry 111: Electrochemical Reactions » Revision Of Oxidation And Reduction

# Revision of Oxidation and Reduction

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## Revision of oxidation and reduction

You should remember the terms oxidation and reduction from Grade 11:

• $$\color{blue}{\textbf{Oxidation}}$$ involves a loss of electrons

• $$\color{red}{\textbf{Reduction}}$$ involves a gain of electrons.

An easy way to remember this is:

In both oxidation and reduction a transfer of electrons is involved resulting in a change in the oxidation state of the elements.

• An element or compound that loses electrons is $$\color{blue}{\textbf{oxidised}}$$.

e.g. $$\color{blue}{\textbf{Zn(s)} \to {\textbf{Zn}}^{\textbf{2+}}\textbf{(aq) + 2e}^{\textbf{-}}}$$

As it loses electrons it gives them away to another element or compound and the element or compound it gives the electrons to is $$\color{red}{\textbf{reduced}}$$.

This makes the compound or element which loses electrons a $$\color{blue}{\textbf{reducing agent}}$$.

• An element or compound that gains electrons is $$\color{red}{\textbf{reduced}}$$.

e.g. $$\color{red}{\textbf{Cu}^{\textbf{2+}}{\textbf{(aq) + 2e}}^{\textbf{-}} \to \textbf{Cu(s)}}$$

As it gains electrons it takes them away from another element or compound and the element or compound it takes them from is $$\color{blue}{\textbf{oxidised}}$$.

This makes the compound or element which gains electrons an $$\color{red}{\textbf{oxidising agent}}$$.