Let us consider 1 mol of gas. If It Is an ideal gas then< br> `(Poverset-V)/(RT)` = 1 where , `overset-V` = molar volume of a gas
For a non-ideal gas this quotient may not be equal to 1. It can also be less than or greater than 1. Therefore, the above quotient is defined as compressibility factor Z.
Z = `(Poverset-V)/(RT)` = (Molar volume of real gas)/ (Molar volume of ideal gas)
The compressibility factor of real gases can be written as Z = `(Poverset-V)/(RT)=1+B/overset-V+C/overset-(v^2)+D/overset-(v^3)......(Viral equation)`
Where B,C,D are called virial coefficients and are dependent on the nature of the gas and temperature. `B=(b-a/(RT))` .At Boyle’s temperature,second virial coefficient becomes zero.
when `Zgt1`repulsive forces are dominant and when `Zlt1` the forces of attraction are dominant. Which of the following statements is correct ?

Options

A. When `Zgt1`, real gases are difficult to compress
B. When Z = 1, real gases are difficult to compress
C. When Z =1 .real gases are easily compressed
D. When `Zgt1`, real gases are easier to compress

Answer

D