Credit hours
In-class work per week |
Practice per week |
Credits |
Duration |
Total |
4 |
0 |
8 |
15 weeks |
120 hours |
Instructor
Marcelo Eduardo Alves
Objective
This course aims to provide graduate students with a broader understanding of the physicochemical concepts of soil science. It will also enable students to perform chemical calculations and critically interpret their results.
Content
(1) REVIEW OF FUNDAMENTAL TOPICS: 1. Aqueous solutions. 2. Concentration units. 3. Dilution calculations. 4. Rates of chemical reactions. 5. Concentration and temperature effects on chemical reaction rates. 6. Order of chemical reactions. 7. Chemical equilibrium. (2) THERMODYNAMICS OF AQUEOUS SOLUTIONS: 1. First law of thermodynamics. 2. Enthalpy. 3. Enthalpy of reaction. 4. Hess's law. 5. Spontaneity of chemical reactions. 6. Entropy and second law of thermodynamics. 7. Gibbs's free energy. 8. Free energy and temperature. 9. Free energy and equilibrium constant. 10. Van't Hoff's equation. (3) ACTIVITY IN AQUEOUS SOLUTIONS: 1. Coligative properties of electrolytic solutions. 2. Ion activity. 3. Calculation of activity coefficients using the Debye-Hückel, Truesdell-Jones, and Davies approaches. 4. Thermodynamic equilibrium constant. (4) ACID-BASE EQUILIBRIUM: 1. Arrhenius and Brönsted-Lowry acid-base theories. 2 pH scale. 3. Water self ionization. 4. Strong and weak acids and bases. 5. The sulfuric acid. 6. pH of salt solutions. 7. Buffers. 8. Acid-base titration curves. 9. Visual MINTEQ applications on pH calculations, titration curves simulations, and on the assessment of pH effects on the relative concentrations of chemical species derived from weak acid and bases. (5) COMPLEXATION EQUILIBRIUM: 1. Acids and bases of Lewis. 2. Defintions of coordination compounds. 3. Formation of coordination compounds. 4. Conditional stability constant. 5 Aquo-complexes. 6. Quelation by organic molecules. 7. Complexation/quelation effects on bioavailabilty of chemical elements. 10. Complexation/quelation calculations with Visual MINTEQ software. (6) SOLUBILITY EQUILIBRIUM: 1. Solubility. 2. Solubility constant. 3. Factors that affect the solubility. 4. Precipitation. 5. Stability diagrams. 6. Visual MINTEQ calculations focusing on pH, ionic strenght and complexation effects of solubility. 7. Calculation of precipitaion curves using Visual MINTEQ. (7) REDOX EQUILIBRIUM: 1. Fundamental concepts. 2. Reduction standard potential. 3. Nernst's equation. 4. Electron activity (pe). 5. Redox potential (Eh). 6. pe x pH and Eh x pH diagrams. 7. Visual MINTEQ calculations focusing on pe effects on the chemical species distribution. (8) SOLUTE SPECIATION IN AQUEOUS SOLUTIONS: 1. Fundamentals and importance of the solute speciation. 2. Mathematical basis of solute speciation. 3. Analytical data needed to the solute speciation of aqueous solutions. 4. Use of Stockholm Humic and NICA-Donnan models to model cationic complexation by humic substances in aqueous solution. 5. Redox effects on the solute speciation in aqueous solutions. 6. Solute speciation of aqueous solutions using Visual MINTEQ.
Bibliography
APPELO, C.A.J.; POSTMA, D. Geochemistry, groundwater and pollution. 2nd. Ed. Leiden: A.A. Balkema Publishers. 2005. 649p. BROWN, T.L.; LEMAY Jr., H.E.; BURSTEN, B.E.; MURPHY, C.J.; WOODWARD, P. Chemistry: The central science. Upper Sadle River: Pearson Education, Inc. 2009. 1117p.
ESSINGTON, M.E. Soil and water chemistry: An integrative approach. Boca raton: CRC Press. 2004, 534 p. FREISER, H.; FERNANDO, Q. Ionic equilibria in analytical chemistry. New York: John Wiley & Sons Inc. 1963, 334p.
GARRELS, R.M.; CHRIST, C.L. Solutions, minerals and equilibria. New York: Harper & Row Publishers Inc., 1965. 450p. HARNED, H.S.; OWEN, B.B. The physical chemistry of electrolytic solutions. New York: Reinhold Publishing. 1950, 645p.
JACKSON, M.L. Soil chemical analysis: Advanced course. 2nd. Ed. Madison: Parallel Press. 2005. 930p. LANGMUIR, D. Aqueous environmental geochemistry. Upper Saddle River: Prentice-Hall, Inc. 1997. 600 p. LINDSAY, W.L. Chemical equilibria in soils. New York: John Wiley & Sons Inc. 1979. 449p.
RODELLA, A.A. Introdução à especiação iônica em solução aquosa. Piracicaba: FEALQ. 2006. 141 p.
TABATABAI. M.A.; SPARKS, D.L. Chemical processes in soils. Madison: Soil Science Society of America, Inc. 2005. 723 p.
WOLT, J.D. Soil solution chemistry: applications to environmental science and agriculture.New York: John Wiley & Sons Inc. 1994. 345p.