What is the difference between oxidation and reduction?

In chemistry if a substance is oxidised it loses electrons in a reaction.

If a substance is reduced it gains electrons in a reaction.

A reaction that has both oxidation and reduction within it is called a REDOX reaction. We can write REDOX reactions as half equations - this can make it easier to see what is going on in the reaction.

For example, Zinc oxide can be reacted with Carbon to extract Zinc:

2ZnO + C --> 2Zn + CO2

In this reaction one of the substances is oxidised and one is reduced. If we write them as half equations:

Zn+ + e- --> Zn

C --> C2+ + 2e-

These equations show that Zn has GAINED an electron to have a neutral charge - there for it has been REDUCED.

Carbon has LOST 2 electrons to become C2+ - therefore it has been OXIDISED.

TC

Related Chemistry GCSE answers

All answers ▸

Why is Copper used in cooking equipment and wiring?


CO(g) + 2H2(g) ⇌ CH3OH(g). A pressure of 100 atmospheres is used instead of atmospheric pressure. The higher pressure gives a greater yield of methanol and an increased rate of reaction. Explain why.


What is an isotope?


An equilibrium between hydrogen and nitrogen to make ammonia. Explain what would happen to the amount of product if a) pressure was increased b) temperature was increased c) a catalyst was added. Energy change -92KJ/mol