Question

In a real gas equation pv = zRT, depending on the values of pressure and temperature of the real gas, the value of z
1. Should always be less than 1
2. May be less than 1, may be greater than 1 or equal to 1
3. Should always be greater than 1
4. Should always be equal to 1

Answer 1

Correct Answer - Option 2 : May be less than 1, may be greater than 1 or equal to 1

Explanation:

In a real gas equation, the compressibility factor z is given by-

\(Z = \frac{{PV}}{{RT}}\)

The value of compressibility factor z may be greater than one, less than one or equal to one depending upon the pressure P and temperature T of the real gas.

• At low pressure and low temperature, z < 1 (In this condition, molecular attraction dominates)
• At low pressure and high temperature or ideal gas condition, z = 1
• At low temperature and high pressure, z > 1 (In this condition, the co-volume is high)

The interaction between the molecules from the value of z.