The viscosity of strong electrolytes measured by a differential method

Abstract

Until quite recently no satisfactory equation had been obtained for the representation of the viscosity of dilute solutions of strong electrolytes. An empirical equation was recently proposed by Jones and Dole to fit the only accurate data then available. Their equation may be represented thus : η = 1 + A √ c + Bc, η = relative viscosity of the solution c = concentration in moles per litre A and B are constants. Jones and Dole realized that the coefficient A is due to interionic forces and in a series of later publications Falkenhagen, Dole and Vernon have deduced a theoretical equation giving values of A in terms of well-known physical constants. Their complete equation may be written η = 1 + ε √Nv1z1/30η0 √1000DkT (z1 + z2) 4 π × [¼ μ1z2 + μ2z1/ μ1μ2 - z1z2 (μ1 - μ2)2/μ1μ2 (√μ1z1 + μ2z2 + √(μ1 + μ2) (z1 + z2) )2]√c, where N = Avogadro's number v1, v2 = numbers of ions z1, z2 = valencies of ions μ1, μ2 = absolute mobilities of ions D = dielectric constant of solvent k = Boltzmann's constant ε = electronic charge η0 = viscosity of solvent T = absolute temperature.