Temperature dependence of the diffusion coefficient of sulfuric acid in water

Abstract

The method of restricted diffusion has been applied to aqueous sulfuric acid in order to determine differential diffusion coefficients spanning the composition range from 0.5 to 5.5 M, at temperatures between 0 and 35 degrees C. Rayleigh interferometry was used for measuring concentration differences with time. The following expression summarizes the experimental data D=exp[C-0(1/T-1/298.15)]C-1 cm(2)/s where C-0=exp{7.699+0.2352[1-exp(-12c(1/2))]-0.2977c+0.04164c(3/2)+0.02023c(2) } C-1=exp{-10.56-0.3665[1-exp(-12c(1/2))]-0.1107c+0.2888c(3/2)-0.09151c(2) } and c is in mol/liter (M). The activation energy of diffusion corresponds to the average value of the activation energy between solvent-anion and solvent-cation interactions