Changing the Temperature Given is the gas-phase hydration of ethylene to ethanol: C2H4+H2OC2H5OH At 298K and 1 bar the Gibbs free energy of reaction and the enthalpy change of reaction are, respectively: G=8.4kJ/molH=45.8kJ/mol (Note that to obtain G&H water is assumed to be a gas. This is slightly unrealistic at 298K, but a good tool to obtain the equilibrium constant at higher temperatures, as it avoids the complication of a phase transition). (a) Calculate the heat exchanged during the reaction to produces 10 mol of ethanol at 298K. (b) Calculate the equilibrium constant at 298K and 1bar. (c) Calculate the equilibirium constant at 500K and 1 bar. (d) Based on the information available state whether it is expected that the equilibrium constant will increase or decrease as the reaction temperature increases. The most straight forward solution requires knowledge of the temperature dependence of the molar reaction enthalpy and, therefore, the enthalpies of all components. For the present reaction this information is available from the NIST Chemistry Web book. Often the temperature dependence of the reaction enthalpy is not available. In such a case it is possible to use the following approximations: (i) Assume that the molar reaction enthalpy is temperature independent. (ii) Assume that the molar reaction enthalpy is temperature dependent but that the heat capacities of all components are temperature independent between 298K and 500K. To explore the accuracy of these approximations plot all enthalpies and the reaction enthalpy as a function of temperature over the relevant temperature range. Do the same for the molar heat capacities and ivicPi Comment on the absolute values and the temperature dependence of all the properties that have been plotted. Comment on how these results affect the accuracy of the approximations. Finally calculate the equilibrium constant at 500K using the equations developed and discuss the results. This question is partly taken'from a standard Thermodynamics textbook (Smith, Van Ness and Abbott, 1996.)