Electrolysis Basics
Year 9 ⚗️ Chemical Reactions Describe electrolysis; predict products at anode and cathode.
⚡ What is Electrolysis?
Electrolysis is the decomposition of an ionic compound (molten or in solution) using electrical energy. Ions are discharged at electrodes.
Key Terms
$$\text{Anode (+) = Oxidation (OIL)} \quad \text{Cathode (−) = Reduction (RIG)}$$ OIL RIG: Oxidation Is Loss, Reduction Is Gain (of electrons).
🔋 Products at Electrodes
| Electrolyte | Cathode (−) | Anode (+) |
|---|---|---|
| Molten NaCl | Sodium metal | Chlorine gas |
| CuSO₄ solution | Copper metal | Oxygen gas |
| Dilute H₂SO₄ | Hydrogen gas | Oxygen gas |
| NaCl solution | Hydrogen gas | Chlorine gas |
📝 Half-Equations
Molten NaCl Example
$$\text{Cathode: } \text{Na}^+ + e^- \rightarrow \text{Na} \quad (\text{reduction})$$
$$\text{Anode: } 2\text{Cl}^- \rightarrow \text{Cl}_2 + 2e^- \quad (\text{oxidation})$$
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Interactive Demonstration — Electrolysis Basics
⚡ Electrolysis Calculator
Q = It (charge) and moles = Q / (n × F) where F = 96,500 C/mol.