CH353
 Physical Chemistry I Spring 2015, Unique 51170 Homework, Week 6 
Homework,
week 6 Answer key 1. Chloroform can be synthesized from natural gas and elemental chlorine according to the following reaction: CH_{4}(g) + 3 Cl_{2} (g) > CHCl_{3}(l) + 3 HCl(g) a) Determine the Gibbs energy, deltaG˚_{rxn} for this system. b)
Assuming deltaH˚_{f}
and S˚_{m} remain constant, will this
reaction proceed spontaneously at 500 K? Data listed in the
posted pdf file might be useful. 3. Provide a physical interpretation for the Helmholtz energy, deltaA, of any reversible transformation. 4. a) What is the volume dependence of the enthalpy of an ideal gas held at constant temperature? b) A gas obeys the following equation of state: P(Vb) = nRT where b > 0 always. What is the volume dependence of the enthalpy of this gas at constant temperature? Account for any differences from your solution to part a. 5. a) What is the change in the Gibbs free energy of one mole of an ideal gas at 300 K when the pressure is increased isothermally and reversibly from 1 bar to 10 bar? b) What is the change in the Gibbs free energy of 18 g of a liquid with a density of 1.0 x 10^{3} kg m^{3} held at 300 K when the pressure is increased isothermally and reversibly from 1 bar to 10 bar? c) Explain the reason for the difference in your answers for parts a and b. 
