Question

The variation of compressibility factor (Z) with pressure $(p$ in bar) for some gases are shown in the figure below. Identify the gases $(A),(B)$ and $(C)$ respectively

• A. real gas, $N _{2}, CO _{2}$
• B. ideal gas, $H _{2}, CO _{2}$
• C. ideal gas, $CO _{2}, H _{2}$
• D. real $gas , H _{2}, CO _{2}$

Answer 1

Answer: (B)

The extent of deviation shown by real gases from ideal behaviour is measured in terms of compressibility factor $(Z)$ which is defined as the ratio of $p V$ and $n R T$.

Mathematically,

$Z=\frac{p V}{n R T}$

For ideal gases, $Z=1$

Easily liquefiable gases such as $CO _{2}$ exhibit larger deviation as compared to gases such as $H _{2},\, O _{2},\, N _{2}$ etc., that liquefy with difficulty.