Question

Compressibility factor, Z of a gas is given as $Z=\frac{pV}{nRT}$

(i) What is the value of Z for an ideal gas?

(ii) For real gas what will be the effect on value of Z above Boyle's temperature?

Answer 1

(i) For ideal gas, compressibility factor , Z=1.

(ii) Above Boyls's temperature, real gases show positive deviation.

So, Z>1

Note Following important points come out from the compressibility factor ,$Z=\frac{pV}{nRT}$

(i) For ideal gas Z=1 at all temperatures and pressures because pV=nRT.

(ii) At very low pressure all gases shown have $Z\simeq 1$ and behave as ideal gas.

(iii) At high pressure, all the gases have Z > 1 These are more diffocult to compress.

(iv) At intermediate pressures most gases have Z< 1.