Question

The given graph in Fig represents the variation of Z $(compressibilityfactor=\frac{pV}{nRT}$) vs.P , for the three real gases A,B and C.identify the only incorrect statement
$1-\frac{pb}{RT}$

• 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 which neither a nor b=0.By konowing 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 which neither a nor b=0.By konowing the minima and the point of intersection with z=1,a and b can be calculated.

B relates to the incompressible volume of the molecules and measures the effective size of gas molecules.
$Z=\frac{pV}{RT}=1$ for an ideal gas.

Note : options (A) , (B) and (D) are well established Eliminating the right statements,
option C is the required Answer C must be incorrect