Question

The compressibility factor for a real gas at high pressure is :

• A. $1 + RT/Pb$
• B. $1$
• C. $1 + Pb /RT$
• D. $1 - Pb/RT$

Answer 1

Answer: (C)

$1 + Pb /RT$

Answer 2

$\left(P+\frac{a}{V^{2}}\right)\left(V-b\right) = RT$ at high pressure $\frac{a}{V^{2}}$ can be neglected $PV - Pb = RT$ $PV = RT + Pb$ $\frac{PV}{\text{RT} } = 1 + \frac{Pb}{RT}$ $Z = 1+\frac{Pb}{RT}\quad;\quad Z > 1$ at high pressure