Question

Non-idealities in the pressure dependence of a real gas can often be treated with a corrective fugacity coefficient that modulates the pressure, providing an effective pressure for the gas. a) Calculate the difference chemical potential of N2(g) from an ideal gas if it exhibits a fugacity coefficient, of 0.96 at 100 atm and standard temperature. b) Consider two systems with equal amounts of F2(g) and Cl2(g). Which of the systems will have agreater deviation from ideality value further from 1) at low pressure? Explain why in two sentences or less. c) Of the systems in part b), which will have a greater deviation from ideality ( value further from 1) at high pressure? Explain why in two sentences or less.

Answer 1

For an ideal N₂(g), chemical potential is given as -

For a non-ideal N₂(g), chemical potential is given as -

For answer part two, you have to provide data on fugacity for both the gases.

An ideal gas is defined as one in which all collisions between atoms or molecules are perfectly eleastic and in which there are no intermolecular attractive forces.

Cl₂(g) deviates greater than F₂(g) since the atomic radii of Cl₂ is large.Its bigger size provides maximum attraction between chlorine molecules which is directly proportional to the size of the molecule and the boiling point of the liquid made from those molecules.The van de Waals force is stronger in Cl₂ as compared to F₂.