gases like carbon dioxide and methane show more deviation from the ideal gas behavior as compared to gases like hydrogen and helium?
Answers
According to ideal behaviour, molecules have no intermolecular attractions. In gases like carbon dioxide and methane, because of large molecular masses, the van de Waal forces of attraction are much greater. Therefore, they deviate from ideal gas behaviour. Hydrogen and helium with lower molecular masses have less van der Waal forces of attraction
Ideal gas behavior supposes that the only interaction between molecules is when they collide. However, there are weak attractive forces between the molecules in a real gas. The further apart the molecules are, the weaker the attractive forces are. So, when you raise the pressure you're compressing the gas into a smaller volume, making the attractive forces larger. As you decrease the temperature, the kinetic energy of the molecules decreases. When the molecules are moving quickly, the attractive forces have negligible impact. As they move more slowly, their impact increases.
So, as you increase the pressure or decrease the temperature, the effects of the forces between gas molecules become more pronounced, leading to non-ideal behavior.