The vertical axis is labelled incorrectly. It should read $$\frac{PV}{RT}$$where V is the molar volume. This is called the compressibility factor Z. According to the Principle of Corresponding States, Z is a function of the reduced pressure ##P/P_C##, the reduced temperature ##T/T_C##, and the ascentric factor ##\omega##, where the subscript C indicates the value at the critical point and where ##\omega## varies with the specific gas. Graphs of Z as a function of reduced temperature, reduced pressure, and ascentric factor can be found in most thermo books.phantomvommand said:
The mathematical equation for the deviation from ideality of real gases is known as the Van der Waals equation. It is given by:
(P + a(n/V)^2)(V - nb) = nRT
Where P is the pressure, V is the volume, n is the number of moles, T is the temperature, a is a constant related to intermolecular forces, and b is a constant related to the volume of the gas molecules.
The Van der Waals equation takes into account the non-ideal behavior of real gases, while the ideal gas law assumes that gases behave ideally. The Van der Waals equation includes two additional parameters, a and b, which account for the attractive forces between gas molecules and the volume occupied by the gas molecules, respectively.
The constant 'a' in the Van der Waals equation represents the strength of the intermolecular forces between gas molecules. It is a measure of how much the gas molecules attract each other, and it is different for each gas.
As temperature increases, the deviation from ideality decreases for real gases. This is because at higher temperatures, gas molecules have more kinetic energy and are able to overcome the attractive forces between them, making them behave more ideally.
No, the Van der Waals equation is an approximation and cannot accurately predict the behavior of all real gases. It is most accurate for gases at low pressures and high temperatures, and it becomes less accurate at high pressures and low temperatures.