We will study here ethyne [also known as acetylene] (1) and 1,1-difluoro ethane [also known as R-152a] (2) system at 303.2 K. Predict the Pxy diagram for the above system using the gamma-phi modeling method. You may employ the 2-parameter Margules and the virial equations.

a) Explain in words and with equations (without solving the equations) step by step, a solution method to plot a Pxy diagram using the gamma-phi method including all parameter/properties numerical values needed (e.g., partial pressures, critical pressures, critical temperatures, etc)

b) For the - model you may assume that = . How do you justify this assumption? (what is the physical meaning of this consideration?)

c) Find numerical values for the predicted Pxy data

d) Plot: the gamma-phi predicted data, the experimental (table below) data, Raoult's Law, and modified Raoult's law predicted data, if possible (if not too crowded), in a single plot. Plot experimental data as symbols and models with solid, dashed, and dotted lines. e) How does the gamma-phi predicted values compare with Raoult's law, modified Raoult's law, vs experimental data for this system at the studied conditions