Redox equations are a big part of all chemistry since this explains the chemistry behind some of the chemical reactions. It must be noted that not all chemical reactions are redox reactions.
In order to see whether a reaction is a redox reaction or not, and to check what has been reduced or oxidized the following steps can be followed:
- If an atom combines with Hydrogen then it is reduced while if it combines with Oxygen it would be oxidized.
- An acronym OIL RIG can be used. This means that Oxidation is the loss of electrons while reduction is gain of electrons.
- The most important definition is that which states that oxidation is an increase in the oxidation number while reduction is a decrease in oxidation number. The oxidation number can be said to be the valency of the atom in the compound.
Oxidation numbers
In order to ensure that redox reactions are easy to follow the following oxidation numbers should be known, especially due to the fact that these values are the same as the valency.
| Grp 1 metals | Always +1 |
| Grp 2 metals | Always +2 |
| Hydrogen | Always +1 except when bonded to a grp 1 metal where it would be -1 |
| Oxygen | Always -2 |
| Fluorine | Always -1 |
| Compounds | Total 0 |
Apart from these, there are a few more rules:
- Any element on its own has an oxidation state of 0
- Any compound has an overall value of 0
- Any radical has an overall value of the charge of the radical
Definitions
There are two important definitions:
Oxidising Agent: An oxidizer is any compound that enables another element to be oxidized, while it itself would be reduced. A substance that takes electrons.
Reducing Agent: A reducer is any compound that enables another element to be reduced, while it itself would be oxidised. A substance that donates electrons.