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: (A)

1 + RT/pb

Real gas equation is $(P+\frac{a}{V^2})(V-b)=RT$

At high pressure, $\frac{a}{V^2}$ can be neglected.

$PV-P_b=RT$

$\frac{PV}{RT}=1+\frac{P_b}{RT}$ ..........(i)

$Z=\frac{PV}{RT}$ .......(ii)

$Z=1+\frac{P_b}{RT}$

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Hence, te correct option is $\text{A}$