CBSE Class 12-science Answered

Kohlrausch's research was centered on determining how electricity was conducted in solutions. In his investigations to establish whether Ohm's law also applied to second class conductors, he was the first scientist to utilize alternating current. In this way, he prevented the deposition of decomposition products on the electrodes and obtained highly precise results in his measurements. He used a telephone to monitor the process. The result was that Ohm's law also found to apply to dissolved electrolytes. From 1875 to 1879, he examined numerous salt solutions, acids and solutions of other materials. His efforts resulted in the law of the independent migration of ions, that is, each type of migrating ion has a specific resistance no matter what its original molecular combination may have been, and therefore that a solution's electrical resistance was due only to the migrating ions of a given substances. Kohlrausch suggested that the more dilute a solution, the greater its conductivityKohlrausch's Law on the independence of migrating ions: The molar conductivity of an electrolyte equals the sum of the molar conductivities of the cations and the anions; n = number of anions or cationsKohlrausch's Square Root Law: For strong electrolytes with sufficient dilution, the molar conductivity L_c of an electrolyte of the concentration c is a linear function of the root of the concentration c. L_¥ = molar conductivity at infinite dilution; A = constant which is a function of the valence of the salt