Question

the given graph represents the variation of $Z$ (compressibility factor $=\frac{PV}{nRT})$ versus $P$, for three real gases $A,B$ and $C$. Identify the only correct statement.

• A. For the gas $A,a=0$ and its dependence on $P$ is linear at all pressures.
• B. For the gas $B,b=0$ and its dependence on $P$ is linear at all pressures.
• C. For the gas $C$, which is typical real gas for which neither $a=0$ nor $b=0$. By knowing the minima and the point of intersection, with $Z=1$, $a$ and $b$ can be calculated.
• D. At high pressure, the slope is positive for all real gases.

Answer 1

The correct option is C For the gas $C$, which is typical real gas for which neither $a=0$ nor $b=0$. By knowing the minima and the point of intersection, with $Z=1$, $a$ and $b$ can be calculated.

For the gas $C$ which is a typical ideal gas for which neither $a=0$

nor $b=0$. By knowing minima and point of intersection with $Z=1$ and $b$ can be calculated

$Z=\frac{P{V}_{real}}{RT}$

At high pressure slope is negative for gas $B$.