Question

At a moderate pressure, the van der Waal's equation is written as:

$[P+\frac{a}{V^2}]V=RT$

The compressibility factor is equal to:

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

Answer 1

Answer: (A)

$(1-\frac{a}{RTV})$

The above equation can be written in the form

$\frac{PV}{RT}+\frac{a}{RTV}=1$, where $Z=\frac{PV}{RT}$

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