- Physical Chemistry I
Spring 2012, Unique 52135
Homework, Week 6
1. Chloroform can be synthesized from natural gas and elemental chlorine according to the following reaction:
CH4(g) + 3 Cl2 (g) --> CHCl3(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 pdf file might be
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(V-b) = 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 103 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.