Spontaneity, Entropy & Free Energy

 1 st Law of Thermodynamics  Spontaneous processes  Entropy (S)  Position probability  States of matter  Page 823: #25 & #31

  S universe =  S system +  s surroundings  Temperature  Determining the sign of  S  Free energy  3 rd Law of Thermodynamics  Page 824: #33 & #43

 Standard free energy change (  G o )   G o =  H o – T  S o  Standard free energy of formation (  G o f )  Page 824: #35, 37, 57 & 63

 S large volume > S small volume  S low pressure > S high pressure  G = G o + RTln(P)  G = G o + RTln(Q)  Page 824: # 75 & 77

  G = -RTln(k)  Copy table from board  Example: The standard free energy change for the reaction: N 2 (g) + 3H 2 (g)  2NH 3 (g) is kJ. Calculate the equilibrium constant for this reaction at 25 o C.  Example: Calculate the free energy for the conversion of oxygen to ozone at 25 o C from K P = 2.47 x