Question

A low pressures, the vander Waal's equation is written as [p+ $\frac{a}{v^2}]$V = RT. The compressibility factor is then equal to :

• A. (1 - $\frac{a}{RTV}$)
• B. (1 - $\frac{RTV}{a}$)
• C. (1 + $\frac{a}{RTV}$)
• D. (1 + $\frac{RTV}{a}$)

Answer 1

The correct option is A (1 - $\frac{a}{RTV}$)

$(P+\frac{a}{V^2})V=RT$

$PV+\frac{a}{V}=RT$

$PV=RT-\frac{a}{V}$

$Z=\frac{PV}{RT}=1-\frac{a}{RTV}$

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