Question

The compressibility factor for real gases at low pressure, high pressure and that of gases of low molar masses are z1, z2 and z3. These are

Answer 1

The compressibility factor for real gases at low pressure, high pressure and that of gases of low molar masses are z1, z2 and z3.The values of z1, z2, z3 can be derived as follows.

* At low pressures, the gas equation can be written as,

(P + a/v2m) (Vm) = RT

or Z1 = Vm / RT = 1 – a/VmRT

* At higher pressure,

PV - Pb = RT

So, equating with real gas equation,

PV / RT = 1 + Pb/RT

Again, Z2 = PV / RT

So, Z2 = 1 + Pb / RT.