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Autoionisation of water

Autoionisation of water

Autoionisation of water showing proton transfer between water molecules to form hydronium and hydroxide, plus the simplified H+ and OH- equation and Kw relation

Pure water is not made only of neutral molecules. A tiny fraction of water molecules transfer protons between themselves, so the equilibrium 2H2O(l)⇌H3O+(aq)+OH−(aq)2\text{H}_2\text{O}(l) \rightleftharpoons \text{H}_3\text{O}^+(aq) + \text{OH}^-(aq)2H2​O(l)⇌H3​O+(aq)+OH−(aq) is always present.

The ionic product of water, Kw (A-level only) Lesson

  1. A Level
  2. /Chemistry
  3. /The ionic product of water, Kw (A-level only)

Step-by-step lessons on AQA A Level Chemistry The ionic product of water, $K_w$ (A-level only). Each one builds up to exam-style questions. Build confidence with atomic structure, bonding and moles calculations early on, since these underpin the more demanding organic mechanisms, equilibrium and practical-analysis topics that dominate Year 2.

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