Question

Consider the following graph and identify how many statements are correct for real gas

(i) At point $A,Z$ approaches one and gas shows ideal behavior
(ii) For curve $AB,Z<1$, force of attraction increases on increasing pressure
(iii) At point $B$, value of compressibility factor is minimum
(iv) For the curve $BC,Z<1$, force of repulsion increases on increasing pressure
(v) At point $C,Z=1$, force of attraction are not equal to force of repulsions
(vi) At the curve $‘C{D}^{\prime },Z>1$, gas is more difficult to compress

• A. 5.00
• B. 5.0
• C. 5

Answer 1

Answer: (A), (B), (C)

The gas compressibility factor $\left(Z\right)$ tells us how much the real gas deviates from the ideal gas at a given pressure and temperature.
$Z=\frac{P{V}_{\text{actual}}}{RT},\text{For 1 mol of gas}$
At point $C$,
$Z=1$, but gas is not ideal in nature, force of attraction are equal to force of repulsion.

As the pressure increases at a given temperature, initially attractive for increases between the molecules and hence the value of $Z$ decreases but with further increase in pressure repulsive force dominates and $V_{\text{actual}}$ increases gradually and corrspondingly value of $Z$ also increases.