Ch. 2. THERMODYNAMICS FOR AQUEOUS GEOCHEMISTRY

Ch. 2. THERMODYNAMICS FOR AQUEOUS GEOCHEMISTRY • 2-1. Definitions - A review of undergraduate level thermodynamics • Systems: Open, Closed, Isolated, (Adiabatic) • Paramters: extensive, intensive • Functions: Path dependent & Independent (static) • Phases, components, degree of freedom • Gibbs phase rule • F=C-P+2=C’-P+2-R (C’; no of species, R; no. of rxn) 2-1

Ch. 2. • 2-1. • Reactions: • Homogeneous vs heterogeneous (rxn) • Reversible vs irreversible rxns • Congruent vs incongruent rxns • Internal energy (U) • Entropy (S) • Enthalpy (H) • Gibbs free energy (G) • Chemical potential (m) 2-2

Ch. 2. • 2-1. • Fist Law • Second Law • Third Law • State of a system: Evolutionary (disequilibrium), steady, & equilibrium • How do you determine evolution direction?: spontaneity problem • What is the qualitative meaning of U, S, H?? 2-3

Ch. 2. • 2-2. Equilibrium constant K • For a reaction aA + bB = cC + dD DGr = total G of prod. – total G of reactants = SniGi = cGC + dGD – aGA – bGB = DGro + RT ln {[C]c[D]d/[A]a[B]b} When equil., ln K = - DGro /RT (Read the text from p.10 to 19 for the solution models) 2-5

Ch. 2. • 2-2. • Effects of T-P changes on K (Read text from p.19 to 32) Compare this with the T-P dependency calculation of Gibbs free energy than converting it to K 2-6

Ch. 2. • 2-2. • Check the following terms • Concentrations • Solutions • Mathematical expressons of activity quotuent (Q) • Internal consistency of a dataset 2-7

Ch. 2. • 2-2. • Assignments • P. 34 problems 1, 2 and 5 • P. 35 problems 8 2-8

Ch. 2. THERMODYNAMICS FOR AQUEOUS GEOCHEMISTRY