## Quick Reference

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*+*B*Λ^{0}_{m}, where Λ^{0}_{m} is the limiting molar conductivity.*A* = *z*^{2}*eF*^{2}/3πη(2/ε*RT*)^{½},*B* = **qz**^{3}*eF*/24πε*RT*(2/ε*RT*)^{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* = *z*^{2}*eF*^{2}/3πη(2/ε*RT*)^{½},*B* = **qz**^{3}*eF*/24πε*RT*(2/ε*RT*)^{½}

*Subjects:*
Chemistry.

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