Hofmann voltameter in use. The Hoffman voltameter is an apparatus designed by German chemist August von Hoffman in 1866 to demonstrate electrolysis of water. Three glass tubes are connected by a bridge near their bases. The middle tube is used to fill the apparatus with water and a small amount of electrolyte (e.g. dilute sulphuric acid). Each of the other tubes has a platinum electrode sealed into its base and is stoppered at the top. When a current is applied to the electrodes,hydrogen is liberated at the cathode and oxygen at the anode in the volume ratio of 2:1. If both gases are diatomic (which they are),this shows that water contains twice as many hydrogen atoms as oxygen - H2O | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Trevor Clifford Photography |
Bildgröße: | 3429 px × 5123 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |