Question

Among the following gases which one is most likely to behave as an ideal gas?
$A.{\text{ }}C{O_2}$
$B.{\text{ He}}$
$C.{\text{. S}}{{\text{O}}_2}$
$D.{\text{. }}{{\text{N}}_2}$

Answer 1

Hint : An ideal gas is a hypothetical gas composed of many randomly moving point particles that only undergoes elastic collisions and is free from any kind of force of intermolecular attraction. They just collide elastically with the walls of the container and with each other but do not undergo any kind of interaction.

Complete Step By Step Answer:
The particles of ideal gas are supposed to be perfect hard spheres which do not have volume and they just elastically collide with each other but there is no intermolecular interaction between them.
So, from above, we understood the concept of real gas, so looking at our options –
We can say that a real gas Helium $(He)$ is supposed to behave best as an ideal gas.
This can be attributed to the fact – that Helium $(He)$ can exist as a single atom in nature, while the other gases are unstable as a single atom. Helium $(He)$ is stable being a single atom and this makes it devoid of negligible amount of van der Waals dispersion force, hence, no collision.
Another important factor is this also, that it has a complete valence shell as being a noble gas.
While all the options given have intermolecular attractions among them which renders them less towards the ideal behaviour.
Therefore our option B is correct i.e. Helium $(He)$

Note :
The main difference between real gas and ideal gas is that real gas has volume and can have intermolecular force of interaction among them. But at high temperature and low pressure, a real gas can behave like an ideal gas