REDOX reactions are reactions that involves both Reduction & Oxidation simultaneously.
There are 4 ways to look at whether a substance has been oxidised or reduced, and they are:
1. Gain/Loss of Oxygen atoms
2. Gain/ Loss of Hydrogen atoms
3. Gain/Loss of Electrons
4. Increase/Decrease in Oxidation States/Numbers
Today we will discuss Oxidation / Reduction based on oxygen atoms.
When a substance gains oxygen in a chemical reaction, we say it has been oxidised. The reaction is called OXIDATION.
When a substance loses oxygen in a chemical reaction, we say it has been reduced. The reaction is called REDUCTION.
E.g. Magnesium reacts with copper (II) oxide to produce magnesium oxide and copper metal.
Mg(s) + CuO(s) –> MgO(s) + Cu(s)
From the above equation, you can see that copper (II) oxide has lost oxygen, so it has been REDUCED.
Magnesium, on the other hand, has gained oxygen and so has been OXIDISED.
Now, the copper (II) oxide is said to be an OXIDISING AGENT because it has given oxygen to magnesium and caused the oxidation of magnesium.
The magnesium, on the other hand, is said to be a REDUCING AGENT because it has taken oxygen from copper (II) oxide and caused the reduction of copper (II) oxide.
In the above chemical reaction, we say it is a REDOX Reaction since both OXIDATION and REDUCTION occurs simultaneously.
An OXIDISING AGENT helps the other substance to get OXIDISED, and itself gets REDUCED.
A REDUCING AGENT helps the other substance to get REDUCED, and itself gets OXIDISED.
Hope you find the above discussion on REDOX Reactions (based on Oxygen atoms) useful. Feel free to share it with your friends that are taking O-Level Chemistry (or IGCSE, IB and IP Chemistry).
- O-Level Chemistry: Redox Reactions (Reduction & Oxidation) – Hydrogen Atoms
- O-Level Chemistry: 4 Ways to Identify A Redox Reaction (Oxidation & Reduction)
- O Level Chemistry – Definition of Redox
- O Level Chemistry – Analogy for Oxidising & Reducing Agents
- O Level Chemistry – Secrets of Redox & Electrolysis Series