Open AccessThermodynamics of solution of SO2(g) in water and of aqueous sulfur dioxide solutions
Author(s) -
Robert N. Goldberg,
V. B. Parker
Publication year - 1985
Publication title -
journal of research of the national bureau of standards
Language(s) - English
Resource type - Journals
eISSN - 2376-5259
pISSN - 0160-1741
DOI - 10.6028/jres.090.024
Subject(s) - standard molar entropy , chemistry , enthalpy , aqueous solution , thermodynamics , partial molar property , partial pressure , vapor pressure , bar (unit) , activity coefficient , heat capacity , osmotic coefficient , standard enthalpy of formation , analytical chemistry (journal) , chromatography , organic chemistry , oxygen , physics , meteorology
A consistent set of thermochemical property values, Δ f H °, Δ f G °, S °, and C p o , at 298.15 K is given for the known constituents of aqueous sulfur dioxide (SO 2 0 ( aq ) ,HSO 3 - ( aq ) ,SO 3 2 - ( aq ) , H + (aq), and S 2 O 5 2 - ( aq ) ). Also tabulated are values of the mean ionic activity coefficients, osmotic coefficients, partial pressure of SO 2 (g), and the relative apparent molar enthalpy as a function of concentration of SO 2 (aq) at 298.15 K. The data analysis considered a wide variety of measurement techniques: calorimetric enthalpies of solution and reaction, heat capacities, equilibrium constants, solubilities, and vapor pressure measurements, both partial and total, over aqueous solutions of SO 2 for the temperature range 278 to 393 K. All auxiliary data have been taken from the most recent set of CODATA values which were converted to a standard state pressure of one bar (0.1 MPa). For the processSO 2 ( g ) = SO 2 0 ( aq ) , the selected "best" values are: K = 1.23±0.05 mol kg -1 bar -1 , Δ G ° = -0.5±0.10 kJ mol -1 , Δ H ° = -26.97±0.30 kJ mol -1 , and Δ C p o = 155 ± 10 Jmol - 1K - 1. The standard state partial molar entropy ofSO 3 2 - ( aq ) , obtained by the analysis of data via two independent thermodynamic pathways is -15.40±0.80 J mol -1 K -l at 298.15 K. Parameters are given which extend the predictions to temperatures up to 373 K.