Question

c) The standard enthalpies of formation and molar entropies of phosgene, carbon monoxide, and chlorine are COCl2(g): ΔfH° = -220.08 kJ mol-1; S° = 283.8 J mol-1 K-1 CO(g): ΔfH° = -110.53 kJ mol-1; S° = 197.66 J mol-1 K-1 Cl2(g): ΔfH° = 0 kJ mol-1; S° = 223.08 J mol-1 K-1

i) Determine the reaction Gibbs energy for the decomposition of phosgene at 298 K. Is this reaction spontaneous at this temperature? [25 marks]

ii) At what temperature does the decomposition of phosgene become spontaneous? [15 marks]

iii) For an equilibrium mixture of phosgene, carbon monoxide, and chlorine gas would the each of the following move the equilibrium towards the reactants or products?

• Addition of carbon monoxide

• Removal of chlorine

• Increasing the temperature

• Decreasing the pressure

Answer 1