Electrolysis of water Downloads 203 1
Electrolysis (from the Greek lysis = to split, to dissolve) is the decomposition of a chemical substance under the effect of an electric current. The Hoffmann Voltmeter is an experimental device that enables us to study the electrolysis of water. We speak of the electrolysis of water, but in order to obtain good electrical conductivity, pure water will not suffice, so we have to add an electrolyte, like sulfuric acid (H2SO4. ) Under the action of a potential difference of a few volts, an electrochemical reaction appears at the electrodes: The cathode releases electrons which decompose the water according to the reduction reaction: 2H2O + 2e- --> H2 +2OH- At the anode, the water molecules undergo the following oxidation reaction: 2H2O --> O2 + 4H+ + 4e- The net outcome gives the following equation for decomposition: 2H2O --> O2 + 2 H2
File Type: Manipulative
Grade: Grade 2, Grade 3, Grade 4, Grade 5, Grade 6, Grade 7, Grade 8, Grade 9, Grade 10, Grade 11, Grade 12
Date submitted: July 27, 2012
Publisher Name: eduMedia
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