CEMS 235 Thermodynamics of Materials-Homework#8
due Friday April 24th, 2026
Instructions: Typed papers are preferred, though easily legible handwritten papers are acceptable.
Anything copied and pasted from the internet or other electronic resources will receive zero credit
towards any answer, except in cases where you’re using a figure or image, in which case you must
provide a full reference. Show all work and state all assumptions.
1. You are responsible for the purchase of oxygen gas which, before use, will
be stored at a pressure of 200 atm at 300 K in a cylindrical vessel of
diameter 0.2 m and height 2 m. Would you prefer that the gas behaved
ideally or as a van der Waals fluid (real gas)? The van der Waals constants
for oxygen are a=1.36 liters2·atm·mole-2 and b=0.0318 liters/mole.
2. Two gases, A and B, mix ideally for all compositions at 500 K.
Calculate the ideal molar Gibbs free energy, enthalpy, and entropy of mixing at XB
= 0.25, respectively.