Electrolysis

The separation of a chemical compound into its constituent parts or elements by the action of the electric current. The compound may be decomposed into its elements, as water into hydrogen and oxygen, or into constituent radicals, as sodium sulphate into sodium and sulph i on, which by secondary reactions at once give sodium hydrate and sulphuric acid. The decomposition proceeds subject to the laws of electrolysis. (See Electrolysis, Laws of.) For decomposition to be produced there is for each compound a minimum electro-motive force or potential difference required. The current pa es through the electrolyte or substance undergoing decomposition entirely by Electrolytic Conduction, q. v. in accordance with Grothü ' Hypothesis, q. v. The electrolyte therefore must be susceptible of diffusion and must be a fluid. The general theory holds that under the influence of a potential difference between electrodes immersed in an electrolyte, the molecules touching the electrodes are polarized, in the opposite sense for each electrode. If the potential difference is sufficient the molecules will give up one of their binary constituents to the electrode, and the other constituent will decompose the adjoining molecule, and that one being separated into the same two constituents will decompose its neighbor, and so on through the ma until the other electrode is reached. This one separates definitely the second binary constituent from the molecules touching it. 213   STANDARD ELECTRICAL DICTIONARY. Thus there is an exact balance preserved. Just as many molecules are decomposed at one electrode as at the other, and the exact chain of decomposition runs through the ma . Each compound electrolyzed develops a binary or two-fold composition, and gives up one constituent to one electrode and the other to the other. IMG:8956969607833025625_213F144.jpg: Fig. 144. ACTION OF MOLECULES IN A SOLUTION