CHEM 433 - 10/26/11 IV. 2nd Law of THERMO • Standard Reaction Gibbs energies (3.6) —> what do they really mean? —> what don’t they mean? (Spontaneous vs. Product Favored…) • “Machinery” (3.7) - Properties of dU (3.8) HW – updated … READ: CHAPTER 3 …

Let’s Calc rG° for: H2 (g) + 1/2 O2 (g) —> H2O (l) fG°: 0 0 -273.1 kJ/mol Using fG°’s (This is sorta silly…) Using rH° (-285.8 kJ/mol) and rS° (-163.3 J/K mol) (we calculated these earlier in the semester …) (Note, before we saw that Suniv for the reaction was very positive - about 800 J/K mol!)