Electrolysis of Water

Science · Class 9–10 Watch an electric current split water into hydrogen and oxygen — and see why you always get twice as much hydrogen. syllab.in · free

Electrolysis of Water

🧠 Remember it "Hydrogen doubles at the negative." At the cathode (–) you collect H₂; at the anode (+) you collect O₂ — in a 2 : 1 volume ratio.

🌏 In real life The same idea powers hydrogen fuel: splitting water with (ideally solar) electricity gives clean hydrogen gas that can run a fuel-cell bus, releasing only water when burnt.

📝 Quick notes Passing electricity through water (with a little acid to help conduct) breaks it into hydrogen and oxygen gas. Hydrogen (H₂) collects at the CATHODE — the negative electrode. Oxygen (O₂) collects at the ANODE — the positive electrode. The volume of hydrogen is DOUBLE the volume of oxygen (2 : 1), because water is H₂O — two H for every O.

🎯 Test yourself Which gas is collected at the cathode, and how much compared to the other? Hydrogen (H₂), at the negative cathode — and its volume is double that of oxygen.

See the animated, step-by-step Electrolysis of Water lesson on Syllab

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