Chapter summary
Redox Chemistry, at a glance
Track electrons through reactions, electrolysis and electricity-producing cells.
O-Level 6092 (2026) / SEC G3 K324 (2027)
Quick revision
Revisit the essentials, then return to an explanation when you need it.
| Term | Definition to write |
|---|---|
| Oxidation | Gain of oxygen, loss of hydrogen, loss of electrons, or an increase in oxidation state. |
| Reduction | Loss of oxygen, gain of hydrogen, gain of electrons, or a decrease in oxidation state. |
| Oxidising agent | A substance that oxidises another substance; it is itself reduced (it gains electrons). |
| Reducing agent | A substance that reduces another substance; it is itself oxidised (it loses electrons). |
Pure only
| Term | Definition to write |
|---|---|
| Electrolysis | The decomposition of an ionic compound, molten or in aqueous solution, by passing an electric current through it. |
| Electrolyte | An ionic compound, molten or in aqueous solution, that conducts electricity and is decomposed by it. |
| Anode and cathode | The anode is the positive electrode, where oxidation happens. The cathode is the negative electrode, where reduction happens. |
| Term | Meaning |
|---|---|
| Oxidation | Electron loss; oxidation state rises |
| Reduction | Electron gain; oxidation state falls |
| Oxidising agent | Accepts electrons and is reduced |
| Reducing agent | Supplies electrons and is oxidised |
Pure only
Pure: list all ions, electrode material and concentration before predicting electrolysis products. At the cathode reduction occurs; at the anode oxidation occurs.
Quick recall
Define oxidation in terms of oxygen, electrons and oxidation state.