Fortran Exercise: Vapour Pressure and Partial Pressure

This are essentially trivial examples but will serve to test your understanding of simple programming and `directly solvable' a.e.s. (And a bit of Chemical Engineering!)

The Vapour Pressure Equation

A very simple equation for vapour pressure of a pure component called i at temperature T Kelvin is:

ln P*i = 11(1- T Bi / T)

where TBi is the one atmosphere boiling point of the pure species and all temperatures are in Kelvin.

Write a complete and fully commented program to solve this equation for the vapour pressure of propane (BP -42°C) at a given Celsius temperature. Test it at -42°C and use it to calculate the vapour pressure of propane at room temperature.

Partial Pressure and Mole Fraction Concentration

When a volatile liquid like propane is in equilibrium with its own vapour in the presence of an incondensible gas, e.g. air, then its partial pressure in the gas/vapour phase is equal to its vapour pressure.

The vapour phase mole fraction of propane yi is then the ratio of the partial pressure to the total pressure P:

yi = P*i / P

Write a program to determine the mol fraction of propane in air. Test it at 30°C and 20 atm.