Electric current in liquids: its origin, quantitative and qualitative characteristics

Practically every person knows the definition of an electric current as a directed movement of charged particles. However, the whole point is that the origin and its movement in different environments are quite different from each other. In particular, the electric current in liquids has several other properties than the ordered motion of charged particles. These are the same metal conductors.

The main difference is that the current in liquids is the motion of charged ions, that is, atoms or even molecules, which for some reason have lost or acquired electrons. One of the indicators of this movement is the change in the properties of the substance by which these ions pass. Based on the definition of the electric current, we can assume that during the expansion, the negatively charged ions will move toward the positive current source, and the positive ones, on the contrary, to the negative current source .

The process of decomposition of the solution molecules into positive and negative charged ions was called electrolytic dissociation in science. Thus, the electric current in liquids arises from the fact that, unlike the same metallic conductor, the composition and chemical properties of these liquids change, resulting in the process of moving charged ions.

The electric current in liquids, its origin, quantitative and qualitative characteristics were one of the main problems studied by the famous physicist M. Faraday for a long time. In particular, with the help of numerous experiments, he managed to prove that the mass of the substance released during the electrolysis directly depends on the amount of electricity and the time during which this electrolysis was carried out. For no other reason, except for the kind of substance, this mass does not depend.

In addition, studying the current in liquids, Faraday experimentally found out that to extract one kilogram of any substance during electrolysis, the same amount of electric charges is necessary . This number, equal to 9.65 • 10 7 k., Was called the Faraday number.

Unlike metal conductors, the electric current in liquids is surrounded by water molecules, which greatly hamper the movement of the ions of the substance. In this connection, the formation of a current of only a small voltage is possible in any electrolyte. At the same time, if the temperature of the solution rises, then its conductivity increases, and the electric field strength increases.

Electrolysis has another interesting property. The thing is that the probability of the decay of a molecule into positive and negative charged ions is the higher, the larger the number of molecules of the substance itself and the solvent. At the same time, at some point, supersaturation of the solution with ions occurs, after which the conductivity of the solution begins to decrease. Thus, the strongest electrolytic dissociation will take place in a solution where the concentration of ions is extremely low, however, the intensity of the electric current in such solutions will be extremely low.

The process of electrolysis has found wide application in various industrial processes associated with the conduct of electrochemical reactions. Among the most important of these are the production of metal by electrolytes, the electrolysis of salts containing chlorine and its derivatives, oxidation-reduction reactions, the preparation of such a necessary substance as hydrogen, polishing surfaces, electroplating. For example, in many machine and instrumentation enterprises, the refining method is very common, which is the production of a metal without any unnecessary impurities.