Oxidising and Reducing Agents

Oxidation is the loss of electrons and reduction is the gain of electrons, redox is when both things happen at once. 

Oxidation and reduction reactions can be brought about by oxidising and reducing agents.

A reducing agent is a substance that loses electrons and is oxidised itself. The strongest reducing agents are the alkali metals due to their low electronegativities.

Some reducing agents are used in the chemical industry to help extract metals.

When it comes to IBDP Chemistry, An oxidising agent is a substance that gains electrons and is reduced itself. The strongest oxidising agents are the halogens due to their high electronegativity

Dichromate and permanganate are strong oxidising agents.

Oxidising agents are used for killing fungi and bacteria as well as inactivating viruses and they are also used in everyday life when it comes to breaking down colour (like bleaching hair).

Electronegativity is very useful when predicting whether something will act as an oxidising or reducing agent. Elements with high electronegativity will be strong oxidising agents and elements with low electronegativity will be strong reducing agents

Refer to IBDP Chemistry, The electrochemical series represents a series of reduction reactions with the strongest oxidising agents at the bottom left-hand column and the strongest reducing agents at the top right-hand column

How to write more complex ion-electron equations

1. Check that the main element reacting is balanced - NOT oxygen

2. Add water to balance the oxygen atoms

3. Add H⁺ions to balance the hydrogen atoms

4. Add electrons to the same side as the H⁺ ions so both sides have equal charge

EXAMPLE

MnO₄^- --> Mn²⁺

MnO₄^- --> Mn²⁺ + 4H₂O

MnO₄^- + 8H⁺ --> Mn²⁺ + 4H₂O

MnO₄^- + 8H⁺ + 5e^- --> Mn²⁺ +4H₂O

This is the end of this topic.

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