Indexed on: 07 Mar '14Published on: 07 Mar '14Published in: Russian Journal of Physical Chemistry A
A modified Robinson-Stokes equation that includes the contributions from 1-1 electrostatic interactions between ions to the nonideality of aqueous solutions of electrolytes in the Debye-Huckel theory and the mean ionic hydration in the cluster model is validated. The hydration numbers in the standard state and the dispersion of the distribution of hydration numbers with stoichiometric coefficients are selected as the principal empirical parameters of equations. The equations are tested using the example of concentrated aqueous solutions of alkali metal nitrites, produced from diluted to saturated solutions. It is found that the standard deviations from the descriptions in the literature data are within the range of experimental error and the calculated values of the mean ionic activity coefficients agree with the results from calculations performed with the Hummer-Woo equation.