Electrolysis of Water 3
A hand-held voltage generator is used to convert mechanical energy ito electrical energy to electrolyze water into hydrogen and oxygen gases.
- electrolysis apparatus (see photos)
- The electromagnetic voltage generator is shaken to move the magnet through the wire coil and generate an electrical voltage.
- The voltage is shown on the meter with a document camera.
- The bubbles forming on the platinum wires are also shown on the document camera.
A minimal voltage of 1.23 V is needed to drive the oxidation (although normally an overpotential of 6-8 V is needed to achieve reasonable kinetics for the oxygen half reaction). This is easily achieved with the hand-held voltage generator, leading to hydrogen bubble formation on one platinum electrode and oxygen bubbles on the other.
Interestingly, when the demonstrator stops shaking the generator, a small voltage will persist for some seconds as the oxygen and hydrogen bubbles on the wires are converted back to water (as in a fuel cell).
Special Safety Notes
- hydrogen and oxygen gases are generated in this demo, keep away from open flames.