Redox reactions

High School

Definition

Reactions involving the transfer of electrons between substances, in which one species is oxidised (loses electrons) and another is reduced (gains electrons). Redox reactions power batteries, cause corrosion, and drive respiration.

Worked examples

\(\)Zn\( + \)Cu\(^{2+} \)→\( \)Zn\(^{2+} + \)Cu\(\)

Zinc loses electrons (oxidised) and copper ions gain electrons (reduced) — a redox reaction.

\(\)C\(_6\)H\(_{12}\)O\(_6 + 6\)O\(_2 \)→\( 6\)CO\(_2 + 6\)H\(_2\)O\(\)

Cellular respiration: glucose is oxidised and oxygen is reduced to release energy.

\(4\)Fe\( + 3\)O\(_2 \)→\( 2\)Fe\(_2\)O\(_3\)

Iron loses electrons (oxidised) as it rusts — oxygen gains those electrons (reduced).

Common mistakes

Oxidation means gaining oxygen; reduction means losing oxygen → Oxidation is loss of electrons; reduction is gain of electrons OIL RIG: Oxidation Is Loss, Reduction Is Gain (of electrons). Oxygen transfer is just one type of redox.
Only one substance changes in a redox reaction → Both oxidation and reduction must occur together Electrons lost by one species are gained by another — redox reactions always involve both processes.
The oxidised substance gains electrons → The oxidised substance loses electrons Oxidation = electron loss. The substance that is reduced gains those electrons.

Where you'll use it next

You'll use redox reactions to balance chemical equations with half-reactions, understand electrochemistry and galvanic cells, explore photosynthesis, and analyse oxidation states in advanced chemistry.

Found in 1 StudyPug lesson

Balancing Redox Equations: Unlock Advanced Chemistry

Chemistry

Master the art of balancing redox equations using two powerful methods. Gain essential skills for advanced chemistry, electrochemistry, and real-world applications in corrosion science and battery technology.

11th Grade11th