1. Chemistry 6440 / 7440 Thermochemistry

2. Resources McQuarrie, Statistical Thermodynamics, University Science Books, 1973 Foresman and Frisch, Exploring Chemistry with Electronic Structure Methods, Chapter 4 Cramer, Chapter 10 Jensen, Chapter 12 www.gaussian.com/thermo.html

3. Thermodynamic Functions U(T) - internal energy at absolute temperature T H(T) = U(T) + PV = U(T) + RT - enthalpy S(T) - entropy G(T) = H(T) – T S(T) – free energy

4. Thermodynamic Functions at absolute zero, T = 0 U(0) = H(0) = G(0) U(0) = electronic energy + zero point energy S(0) = 0 for a pure crystalline substance (third law of thermodynamics)

5. Thermodynamic Functions at T  0 U(T) = U(0) +  C v dT –heat at constant volume, molecule gains energy for translation (3/2 RT), rotation (3/2 RT) and vibration (  1/(1-exp(- i /kT)) H(T) = H(0) +  C p dT –heat at constant pressure, molecule gains additional energy from expansion S(T) > 0 –more states become accessible as the temperature increases