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Debye-Hückel-Onsager theory


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A theory providing quantitative results for the conductivity of ions in dilute solutions of strong electrolytes, which enables the Kohlrausch equation to be derived. This theory can be stated as: K = A+BΛ0m, where Λ0m is the limiting molar conductivity.A = z2eF2/3πη(2/εRT)½,B = qz3eF/24πεRT(2/εRT)½,where z is the charge of an ion, e is the charge of an electron, F is Faraday's constant, η is the viscosity of the liquid, R is the gas constant, T is the thermodynamic temperature, and q = 0.586 in the case of a 1,1 electrolyte. The Debye-Hückel-Onsager theory uses the same assumptions and approximations as the Debye-Hückel theory and is also limited to very dilute solutions (usually less than 10−3 M) for which there is good agreement between theory and experiment. The modifications were made by the Norwegian-born US chemist Lars Onsager (1903–76)

A = z2eF2/3πη(2/εRT)½,B = qz3eF/24πεRT(2/εRT)½

Subjects: Chemistry.


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