Fugacities of Mixtures: Example Problems

Try to solve the problem before watching the screencast.

Example Problem 1

Use a Peng-Robinson EOS spreadsheet to calculate fugacities and fugacity coefficients for a three-component system, given pressure, temperature, and mole fractions in the phase. The spreadsheet can be downloaded from http://www.chethermo.net/software. 

Example Problem 2

A) A binary liquid mixture (70 mol% A, 30 mol% B) is in the equilibrium with a vapor that has the partial pressures. 

PA = 0.2 bar   PB = 0.8 bar

Which component has the higher fugacity in the liquid phase? 


B) Enough NaCl is added to liquid water so that salt crystals are present on the bottom of the container at 25 ℃ . Does water or salt have the higher fugacity? 


C) Compare pure water at 75 ℃ with two concentrations in different phases: 0.014 mol/L and 54 mol/L? Which has the higher fugacity?