Understanding equations of state from a non-chemistry perspective

[Loboguy]

I'm learning about the refrigerator model proposed by Einstein and Szilard. Using butane as a refrigerant, ammonia as a pressure equalizer, and water to absorb the ammonia.
http://en.wikipedia.org/wiki/Einstein_refrigerator

I've come across some doctoral research investigating it, but I'm having trouble following the equation of state as I haven't studied chemistry since my Intro to Chemistry college courses in 2007.
http://www-old.me.gatech.edu/energy/andy_phd/two.htm
I understand the concept perfectly, but could someone break down the equations into something easier to follow?

 

[jbsteele]

The equations of state used in this research are the ideal gas law, the van der Waals equation of state, and the Soave-Redlich-Kwong equation of state. Here is a brief overview of each:1. Ideal Gas Law: This equation states that the pressure (P) of a gas is proportional to its temperature (T) and the number of moles of the gas (n) divided by its volume (V). It can be written as P = nRT/V where n is the number of moles of the gas, R is the universal gas constant, and T is the temperature in Kelvin.2. Van der Waals Equation of State: This equation takes into account the attractive forces between molecules, which the ideal gas law does not. It is more accurate for describing real gases than the ideal gas law, and it can be written as P = (nRT)/(V-nb) - (a(n^2))/V^2 where n is the number of moles, R is the universal gas constant, V is the volume, b is a constant related to the volume of the gas molecules, and a is a constant related to the attractive forces between molecules.3. Soave-Redlich-Kwong Equation of State: This equation further takes into account the attractive forces between molecules, and it is also more accurate for describing real gases than the ideal gas law. It can be written as P = (RT)/(V-b) - a/(V^2 + 2bV - b^2) where R is the universal gas constant, V is the volume, b is a constant related to the volume of the gas molecules, and a is a constant related to the attractive forces between molecules.