Summary of electrolysis in dilute sulphate acid

The electrolysis of dilute sulfuric acid is described and explained. This is the classic 'electrolysis of water' experiment and good introduction to electrolysis experiment. The electrode products and electrode equations for the electrolysis of water are quoted. What are the products of the electrolysis of water acidified with dil. sulfuric acid? All the electrode equations for the electrolysis of water are explained and diagrams of the apparatus.

Reminders: Electrolysis (of acidified water) is a way of splitting up (decomposition) of the compound (water) using electrical energy. The electrical energy comes from a d.c. (direct current) battery or power pack supply. A conducting liquid, containing ions, called the electrolyte (dilute sulfuric acid), must contain the compound (water) that is being broken down. The electricity must flow through electrodes dipped into the electrolyte to complete the electrical circuit with the battery. Electrolysis can only happen when the circuit is complete, and an electrical current (electricity) is flowing, then the products of electrolysing dil. sulfuric acid are released on the electrode surfaces where they can be collected. Electrolysis always involves a flow of electrons in the external wires and electrodes and a flow of ions in the electrolyte and there is always a reduction at the negative cathode electrode (which attracts positive ions, cations) and an oxidation at the positive anode electrode (which attracts negative ions, anions) and it is the ions which are discharged to give the products. These revision notes on the electrolysis of acidified water should prove useful for the new AQA chemistry, Edexcel chemistry & OCR chemistry GCSE (9–1, 9-5 & 5-1) science courses.