Objectives of the Solubility Data Series

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Objectives of the Solubility Data Series Mark Salomon MaxPower, Inc. 141 Christopher Lane Harleysville, PA 19438 mark.salomon@maxpowerinc.

1 Objectives of the Solubility Data Series Mark Salomon MaxPower, Inc. 141 Christopher Lane Harleysville, PA Foreword by A.S Kertes appearing in SDS Volumes 1-53 ( ). If the knowledge is undigested or simply wrong, more is not better.

2 Presentation Outline Introduction to the IUPAC Solubility Data Project and the IUPAC-NIST Solubility Data Series. Format for compilation data sheets. Format for critical evaluations Examples of smoothing equations used in regression analyses of data for gas/liquid, liquid/liquid and solid liquid systems. References quoted for this review.

3 Sources of Solubility Data Primary Sources: peer reviewed literature; sheer volume of data overcomes the capacity of 2 o and 3 o services to respond effectively. Some articles in which solubilities are not the main objective can contain briefly measured, sometimes qualitative values which find their way into subsequent literature proliferating the literature with undigested or wrong data. Secondary Sources: review articles often more specialized and limited in scope of literature cited, no indication if material has been excluded by design or less than thorough literature search, lack detailed analyses of numerical data. Tertiary Sources: handbooks, reference books, proprietary company reports are generally uncritical, limited in literature survey, neglect error limits and lack references which users might wish to check.

4 The Solubility Data Project and the Solubility Data Series The IUPAC Solubility Data Project (SDP) addresses the above problems by producing the Solubility Data Series (SDS) in which all available published literature to date on solubility data from all available literature sources for a specific solute/solvent system are precisely detailed on Compilation (data) sheets providing information on materials, experimental methods and errors. Where sufficient literature data exist, contributors to the SDS provide Critical Evaluations comparing literature data to determine their merits. Data can be classified as rejected when qualitative or incorrect, recommended when agreement between different authors exists, or tentative when sufficient literature comparisons cannot be made. Details on preparing Compilations and Critical Evaluations are presented in the following slides.

5 General Format for Compilations (Data Sheets) Components: List of components: formulas, CAR numbers Variables: Temperature, pressure, concentrations Original Measurements: Citation to the primary source of data Prepared by: Name of Compiler Experimental Values Experimental data exactly as they appear exactly in the literature and converted to various convenient units where appropriate. Auxiliary Information Method/Apparatus/Procedure: Experimental apparatus and methods used to determine solubilities. Source and Purity of Materials: Estimated Error: Either from the primary source or estimated by the compiler.

6 General Format for Critical Evaluations Components: List of components: formulas, CAR numbers Evaluator: Name of Evaluator and date of evaluation Based on data in the compilations, the Evaluator discusses the data in terms of experimental methods, purity of materials, reproducibility and precision or accuracy. If sufficient data exist by different authors, the Evaluator will produce a set of data based on weighted averages or an appropriate smoothing equation with estimated standard deviations. The data in this set are designated as either Recommended or Tentative. Data that are judged to be of low precision or in error are either rejected or designated as Doubtful. Graphical plots of Recommended or Tentative data are given where appropriate.

7 Examples of Smoothing Equations used in Critical Evaluations (mole fraction bases for binary gas/liquid & solid/liquid systems) Clarke and Glew s variation* of the van t Hoff equation for solubilities at constant pressure is used extensively in the Critical Evaluations; 1 Y = A BT ClnT DT The solubility function Y is formulated either in mole fraction or molality units. Mole fraction units are useful for solubilities over the entire composition range from very dilute solutions, including hydrates, to the melting point of the anhydrous solid in which case the above equation takes the form (Counioux, Cohen-Adad, Lorimer). v r v r r v r 1 ln x 1 x ( v r) r / r (1 x) A BT ClnT DT For gas solubilities as a function of pressure at constant temperature, the following equation has been used (Battino et al.) 2 ln x A ln P / MPa A P / MPa A P / MPa *E.C.W. Clarke and D.N. Glew, Evaluation of thermodynamic functions from equilibrium constants, Trans. Faraday Soc., 62, 539 (1966).

8 Examples of Smoothing Equations used in Critical Evaluations (molality bases for binary solid/liquid systems) 1 Y = A BT ClnT DT A second and equivalent form of the function Y is useful when hydrates are the solid phase in which case the above equation takes the following form (Counioux, Cohen-Adad, Lorimer, Mioduski et al.) 1 ln( / 0)-( / 0-1) = A B Cln D m m m m T T T Where m 0 = 1/rM 2 is the molality of a binary salt solvate with M 2 the molar mass of the solvent. This equation is particularly useful to accurately confirm and predict metastable solubilities before and after congruent melting points. Other complex methods involving equations for activity coefficients are used providing additional experimental data exist. For example, the solubilities of the alkaline earth carbonates MgCO 3 and BeCO 3 utilized the equation CO CO CO s 1 4K K K a 1 f f f c a b d T mol kg 3 K2 2 3 atm atm atm T M HCO 3 s c 1 w lg lg lg lg lg lg 1 2 where K s is the solubility constant of MCO 3, K c is the solubility constant of CO 2, K 1 and K 2 are the first and second acid dissociation constant of CO 2 /carbonic acid, f(co 2 ) is the fugacity of CO 2, and the values are activity coefficients (De Visscher et al.).

9 Very Old Solubility Studies Solubilities published even in the first half of the 19th century often compare favorably with values measured recently and sometimes constitute the only source of data. Compilations based on these publications not only are possible sources of reliable data but also are sources for the history of science and technology. Example of a compilation for NaCl + H 2 O published in 1885 where solubilities were determined to be Recommended with experimental methods and purity of materials comparable to modern standards is summarized in the following 3 slides.

10 Example of a compilation for NaCl + H 2 O published in 1885

11 From R. Cohen-Adad and J.W. Lorimer, Solubility Data Series, Volume 47. For the critical evaluation of the binary NaCl-water system, 481 data sets fitted by least squares, and after rejecting outliers, 409 data points fitted to the 4-parameter equation to produce a set of Recommended and Tentative solubilities as a function of temperature. Y A / T Bln( T / T ) CT D where T f is a reference temperature (melting point of the solid phase). Selected results for data reported by Raupenstrauch in 1885 are shown below. f

12 Examples of Smoothing Equations used in Critical Evaluations (mole fraction bases for liquid/liquid systems) For binary systems where T c is the upper critical solution temperature and x c,1 is the corresponding critical mole fraction, the solubility of liquid 1 in liquid 2 analyzed by (Góral et al., SDS vol 91) utilized the following equation ln x ln x b ( T / T 1) b (1 T / T ) b (1 T / T ) (1/3) 1 c,1 1 c 2 c 3 c The solubility of liquid 2 in liquid 1 is given by ln x ln(1 x ) c ( T / T 1) c (1 T / T ) c (1 T / T ) (1/3) 2 c,1 1 c 2 c 3 c For ternary systems, experimental data were correlated using the NRTL equation (Góral et al., SDS vol 101 based on the notation of Renon and Prausnitz, AIChE J. 14, 135 (1968)) E G RT 3 3 å j = å å i x i t G 3 k ji G ki ji x x k j

13 Future of the SDP At the present time, 103 SDS volumes have been published and new volumes are in various stages of completion. A number of volumes are quite large and thus have been published in parts in JPCRD bringing the total number of SDS publications to 136. New contributors to the SDS are warmly welcome, and inquiries can be sent to the following: Clara Magalhães, Chair of the Subcommittee on Solubility and Equilibrium Data (SSED). mclara@ua.pt Earle Waghorne, SSED secretary. earle.waghorne@ucd.ie Mark Salomon, SDS Editor-in-Chief. marksalomon@comcast.net Additional information on volumes in preparation is available at the IUPAC web site.

14 Much of this review was taken liberally from the following publications. H.L. Clever, The IUPAC Solubility Data Project. A Brief History: Chem. Intern., 26, No.3, May-June R. Battino, T.R. Rettich and T. Tominaga, The Solubility of oxygen and ozone in liquids; J. Phys. Chem. Ref. Data, 12, (1983). R. Cohen-Adad and J.W. Lorimer, Alkali Metal and Ammonium Chlorides in Water and Heavy Water (Binary Systems), Solubility Data Series, Volume 47, Pergamon Press, G.T. Hefter and R.P.T. Tomkins, Eds., The Experimental Determination of Solubilities, Wiley Series in Solution Chemistry, Chichester, UK J.-J. Counioux and R. Tenu, J. Chim. Phys, 78, 815 and 823 (1981). R. Cohen-Adad, Pure Appl. Chem., 57, 255 (1985). R. Cohen-Adad, J. W. Lorimer, S. L. Phillips, and M. Salomon, A Consistent Approach to Tabulation of Evaluated Solubility Data: Application to the Binary Systems RbCl-H 2 O and UO 2 (NO 3 ) 2 -H 2 O, J. Chem. Inf: Comput. Sci. 35, (1995). T. Mioduski, C. Guminski and D. Zeng, IUPAC-NIST Solubility Data Series. 87. Rare Earth Metal Chlorides in Water and Aqueous Systems. Part 1 Scandium Group (Sc, Y, La), JPCRD 37, 1765 (2008). A. De Visscher et al., IUPAC-NIST Solubility Data Series. 95. Alkaline Earth Carbonates in Aqueous Systems. Part 1. Introduction, Be and Mg. JPCRD 41, (2012). M. Góral, D. G. Shaw, A. Maczynski and B. Wisniewska-Goclowska, IUPAC-NIST Solubility Data Series. 91. Phenols with Water. Part 1. C 6 and C 7 Phenols with Water and Heavy Water, JPCRD 40, (2011).

Minutes INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY SUBCOMMITTEE ON SOLUBILITY AND EQUILIBRIUM DATA

Minutes INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY SUBCOMMITTEE ON SOLUBILITY AND EQUILIBRIUM DATA 39 th Annual Meeting (12 th of SSED) to be held in conjunction with the IUPAC General Assembly,