Things to study for the 4th Exam Chapter 12: Know how to write a K for any reaction. Know how to plug in pressure values to calculate a K Know how to use Q to compare to K for reaction direction Know homogenous and heterogeneous equilibira definitions Know how to predict the reaction direction Know Le Chatelier's Principle and be able to apply it Know how to combine Ks from multiple reactions and how to add reactions to create a new reaction Chapter 17: Know how to calculate the change in entropy Know how to calculate Gibbs Free Energy Know how to use the Q factor to determine reaction direction Know what the signs or Gibbs Free Energy, Enthalpy, and Entropy mean. Know the 2nd law of thermodynamics Know the how S changes with phases Know in general terms the usual direction of a spontaneous reaction Know the third law of thermodynamics Know how pressure and concentration affect Gibbs Free Energy Know the relationship between Gibbs Free Energy and the equilibrium constant DG = -RTlnK Just like DS and DH, know how to add two reactions and how to determine the DG of the combined reaction (Pg 486)