# Solution Thermodynamics and its Application to Aqueous Solutions

**A Differential Approach**

**By**

- Yoshikata Koga, The University of British Columbia, Vancouver, Canada
- Yoshikata Koga, The University of British Columbia, Vancouver, Canada

As the title suggests, we introduce a novel differential approach to solution thermodynamics and use it for the study of aqueous solutions. We evaluate the quantities of higher order derivative than the normal thermodynamic functions. We allow these higher derivative data speak for themselves without resorting to any model system. We thus elucidate the molecular processes in solution, (referred to in this book βmixing schemeβ), to the depth equal to, if not deeper, than that gained by spectroscopic and other methods. We show that there are three composition regions in aqueous solutions of non-electrolytes, each of which has a qualitatively distinct mixing scheme. The boundary between the adjacent regions is associated with an anomaly in the third derivatives of G. The loci of the anomalies in the temperature-composition field form the line sometimes referred as βKoga lineβ. We then take advantage of the anomaly of a third derivative quantity of 1-propanol in the ternary aqueous solution, 1-propanol β sample species β H2O. We use its induced change as a probe of the effect of a sample species on H2O. In this way, we clarified what a hydrophobe, or a hydrophile, and in turn, an amphiphile, does to H2O. We also apply the same methodology to ions that have been ranked by the Hofmeister series. We show that the kosmotropes (salting out, or stabilizing agents) are either hydrophobes or hydration centres, and that chaotropes (salting in, or destablizing agents) are hydrophiles.

View full description### Audience

Researchers, students

### Book information

- Published: October 2007
- Imprint: ELSEVIER
- ISBN: 978-0-444-53073-8

### Table of Contents

Chapter 0 Introduction [0-1] Introduction. [0-2] Qualitative judgments and sciences. [0-3] Outline of this book.PART A A Differential Approach to Solution Thermodynamics.Chapter I. Basics of thermodynamics β Derivatives of Gibbs energy, G. [I-1] System, state, first and second laws of thermodynamics. [I-2] Gilesβ derivation of entropy. [I-2-1] State, process, and irreversibility of process. [I-2-2] Entropy and potentials β defining p and T. [I-3] Logical (mathematical) deduction. [I-4] Stability criteria. [I-5] Multi-component system β Partial molar quantities. [I-6] Excess quantities. [I-7] Response functions. [I-8] Thermodynamic quantities β order of derivative. [I-9] Interaction functions β third derivatives.Chapter II. Solution thermodynamics β Use of the second and the third derivatives of G. [II-1] Mixture. [II-2] Gibbs-Duhem relation. [II-3] Vapor pressures. [II-4] Raoultβs law and Henryβs law. [II-5] Process of mixing β mixing entropy. [II-6] Conversion from ( , ) to ( , N) variable systems.[II-7] Interaction functions due to the ideal mixing entropy. [II-8] Phase separation β Critical point (UCST or LCST). [II-9] Azeotrope.Chapter III. Determination of the partial molar quantities. [III-1] Introduction. [III-2] Calculation of from . [III-3] Experimental determination of excess partial molar enthalpy [III-4] Experimental determination of excess partial molar volume. [III-5] Excess partial molar entropy β excess chemical potential. [III-6] Boissonnas analysis β excess chemical potential. [III-7] Partial pressures of 1-propanol(1P) β H2O: How to deal with an azeotrope.Chapter IV Fluctuations and partial molar fluctuations β Understanding H2O.[IV-1] Introduction.[IV-2] Fluctuation functions β coarse grain.[IV-3] H2O vs. n-hexane.[IV-4] Site-correlated percolation model of H2O.[IV-5] Concentration fluctuation and Kirkwood-Buff integral.PART B Studies of Aqueous Solutions using the Second and the Third Derivatives of G.Chapter V Mixing schemes in binary aqueous mono-ols. [V-1] Mixing schemes in 2-butoxyethanol (BE) β H2O. [V-2] Mixing schemes of other mono-ols (AL) β H2O. [V-3] Fluctuation functions β More about Mixing Scheme I [V-4] Concentration fluctuations β Mixing Scheme II. [V-5] Mixing Scheme III β Second and third derivative quantities in the alcohol-rich region.[V-6] Mixing schemes of aqueous alcohols (AL) studied by other techniques.Chapter VI. Mixing schemes in aqueous solutions of non-electrolytes. [VI-1] Introduction.[VI-2] Type (a) β Aqueous solutions of iso-butoxyethanol (iBE) at 20 oC and acetonitrile (ACN) at 6 to 45 oC. [VI-3] Type (d) β Aqueous solutions of glycerol (Gly), acetone (AC), 1,3-propanediol (13P), and tetramethyl urea (TMU). [VI-4] Type (b) β Aqueous solutions of iso-butyric acid (IBA), and 2-butanone (BUT). [VI-5] Type (c) β Aqueous solutions of dimethyl sulfoxide (DMSO), and 1,2-propanediol (12P). [VI-6] Mixing schemes of aqueous non-electrolytes studied by other techniques.Chapter VII. Effects of non-electrolytes on the molecular organization of H2O:1-Propanol (1P) probing methodology. [VII-1] Introduction - 1-Propanol (1P) probing methodology. [VII-2] Effects of methanol (ME), 2-propanol (2P), and tert-butanol (TBA) on H2O as probed by the pattern change. [VII-3] Effects of urea (U), tetrtamethyl urea (TMU) and acetone (AC) on H2O as probed by the pattern change. [VII-4] Effects of ethylene glycol (EG), 1,2- and 1,3- propanediol (12P and 13P), glycerol (Gly), and poly(ethylene glycol) on H2O as probed by the pattern change. [VII-5] Concluding remarks-Summary.Chapter VIII Effects of ions on the molecular organization of H2O: 1-Propanol (1P) probing methodology.[VIII-1] Introduction β Hofmeister series.[VIII-2] Effects of NaF and NaCl on H2O as probed by the pattern change.[VIII-3] Effects of NaBr and NaI on H2O as probed by the pattern change.[VIII-4] Effects of Na2SO4, NaOOCCH3(NaOAc), NaClO4, and NaSCN on H2O as probed by the pattern change.[VIII-5] Effects of CaCl2, NH4Cl and tetramethyl ammonium chloride (TMACl) on H2O as probed by the pattern change.[VIII-6] Hydration numbers of glycine and its slats as probed by the pattern change.[VIII-7] Concluding remarks in relation to other studies on aqueous electrolytes in the literature. [VIII-7-1] Ion pairing. [VIII-7-2] Hydration number, . [VIII-7-3] Hofmeister series.Chapter IX Interactions in ternary aqueous solutions β General treatment. [IX-1] Introduction. [IX-2] Solute-solute interactions in tert-butanol (TBA) β dimethyl sulfoxide (DMSO) β H2O. [IX-3] Solute-solute interactions in 2-butoxyethanol (BE) β dimethyl sulfoxide (DMSO) β H2O. Chapter X In closing β Executive summary on the effect of solute on H2O.Appendix A B-spline vs. manual graphical differentiation.Appendix B Gibbs-Konovalov correction.Appendix C Heat capacity anomalies associated with phase transition β Two level approximation. Appendix D Freezing point depression.Appendix E Titration calorimetry with dilute titrant.References.