Consider the following statement:

1) In an ideal gas, there are no intermolecular forces of attraction and repulsion.

2) At very low pressure and high temperature, all gases and vapours approach ideal gas behaviour.

3) Enthalpy of an ideal gas depends only on temperature.

Which of the above statements are correct?

Explanation:

1. The assumption in the ideal gas model (PV=RT) is that there is no interaction between molecules and the volume occupied by molecules is negligible as compared to the total volume of the gas system.
2. At very low pressure and high temperature, all gases and vapour approach to ideal gas behaviour.
3. Since internal energy of ideal gas temperature in function of temperature and enthalpy is given as h = u + pV

Since pV = RT

So h = u + RT = f(T) + RT = f(T)

Hence all of the three statements i.e. 1,2 and 3 are correct. So, option (1) is the correct option.