Question

We have `O_2`, `H_2`, `He`, and `HCl` gases; which gas will behave LEAST ideally?

Answer 1

Clearly, `"hydrogen chloride"` behaves LEAST ideally..............

Explanation:

Ideality assumes negligible intermolecular interaction. However, `"hydrogen chloride gas"`, with `""^(delta+)H-Cl^(delta-)` dipoles, has the possibility of intermolecular hydrogen bonding, which is a potent intermolecular force. This is reflected in the respective boiling points of the given gases, `He`, `H_2`, `O_2`, `HCl`, which are `4.2, 20.2, 90.2,` and `188.1` `K` respectively.