Splitting Water with Electricity ⚡
Dilute H₂SO₄ electrolysis — the Hofmann Voltameter
🔬 The Setup
Imagine you're a particle inside dilute sulfuric acid. You're surrounded by four types of ions floating freely: H⁺ and OH⁻ from water, plus H⁺ and SO₄²⁻ from the acid. When we switch on the power supply, it's like opening two doorways — one marked CATHODE (–) and one marked ANODE (+). Which ions rush through which door?
🤔 Ion Eliminator — Who Gets Discharged at the Anode?
Two negative ions compete for the Anode (+). Only one gets discharged (oxidised). Which one wins?
⚗️ Hofmann Voltameter Simulation
🧨 Gas Tester — Identify the Products
The simulation is complete. Now test each tube to confirm the gases!
⚡ The Half-Equations Summary
⚠️ Examiner's Trap
"SO₄²⁻ is discharged at the anode" — WRONG. Sulfate is NEVER discharged in aqueous solution.
"Equal volumes of gas form at each electrode" — WRONG. H₂ is always DOUBLE the volume of O₂ (2:1 ratio).
"H₂SO₄ is used up during electrolysis" — WRONG. H₂SO₄ only provides ions; water is the substance electrolysed.
Always say "preferentially discharged" when OH⁻ wins over SO₄²⁻.
📚 Key Keywords (Earn Marks!)
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