Page 2 3. (24 pts) The fundamental equation of thermodynamics is shown below. It certainly applies to addition polymerization reactions. Consider the polymerization of styrene under standard conditions at 25 degrees C. For this system, the AH, for styrene is -16.7 kcal/mol and the AS, is 25.0 calories/deg. mol. For the following three parts of this question, remember that the units as given for the enthalpy and the entropy are different. Also remember that the T for the equation is in degrees Kelvin. AGAH TAS a.) Calculate the AG in kcal/mol for the reaction at 25 degrees C under standard conditions. b.) Remembering that AG-RT In Ka, calculate the equilibrium constant for the styrene polymerization at 25 degrees C under standard conditions. c.) Addition polymers can depropagate (unzip) if the temperature is high enough. At the point when concentrations of monomer and polymer are equal, the AG is zero. The temperature at which the polymer begins to unzip is called the ceiling temperature, T., It can be calculated by dividing the enthalpy of polymerization (given above) by the entropy of polymerization (also given above). Calculate the ceiling temperature for polystyrene in degrees C. 4. (16 pts) Shown below is an array of 16 circles identical to the array I talked about in lecture. The 16 circles represent 16 molecules with 32 functional groups with one functional group at each end of the molecule. Each molecule can only react with a molecule next to it. The diagram shows the situation in which all molecules have reacted to give a hexadecamer. Using the equations I gave you in class, calculate the extent of reaction (be careful!) and the number average degree of polymerization. О о