Chapter 13- Oxidation and Reduction

Oxidation

1. Gain of oxygen

2. Loss of hydrogen

3. Loss of electrons

4. Increase in oxidation state (e.g. from -1 to 0)

5. For half equation of reduction, electrons are shown on the left side, e.g.

                               Pb2+ + 2e- →Pb
   

Reduction

1. Loss of oxygen
2. Gain of hydrogen
3. Gain of electrons
4. Decrease in oxidation state (e.g. from 0 to -1)

For half equation of oxidation, electrons are shown on the right side, e.g.

                              2Br-   → Br2 + 2e-

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• Oxidation state: the charge an atom of an element would have if it existed as an ion in a compound.

• Redox reactions: chemical reactions which involve oxidation of one substance and reduction of another.

• Oxidising agent: a substance that causes another substance to be oxidised, and is reduced itself in the process.

• Reducing agent: a substance that causes another substance to be reduced, and is oxidised in that process.

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• To check if oxidation or reduction have taken place in an reaction, write a balanced chemical equation with oxidation states, and compare them on both sides.

• Test for oxidising agents:

• Test for reducing agents:

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