Introduction:
At very high pressures, the behavior of an ideal gas differs from that of a real gas. An ideal gas is a theoretical concept that follows the ideal gas law, while a real gas accounts for intermolecular forces and deviations from ideal behavior. The key difference between the two lies in their volume changes under high pressure conditions.

Key Points:

1. Ideal Gas:
- An ideal gas assumes that there are no intermolecular forces between gas molecules and that the volume of the gas molecules themselves is negligible compared to the volume of the container.
- According to the ideal gas law (PV = nRT), the volume of an ideal gas is directly proportional to its pressure. As pressure increases, the volume of an ideal gas decreases.

2. Real Gas:
- In reality, gas molecules do experience intermolecular forces such as van der Waals forces, dipole-dipole interactions, and hydrogen bonding.
- At high pressures, these intermolecular forces become significant and cannot be ignored. The volume of the gas molecules themselves also becomes more significant compared to the volume of the container.
- As a result, the volume occupied by a real gas at high pressures is larger than that predicted by the ideal gas law.

3. Le Chatelier's Principle:
- Le Chatelier's principle states that a system at equilibrium will respond to a stress by shifting its equilibrium position to counteract the stress and restore equilibrium.
- When pressure is increased, a system will respond by reducing its volume to counteract the stress.
- In the case of an ideal gas, where intermolecular forces are assumed to be negligible, the gas molecules can easily compress and occupy less volume under high pressure.
- However, in the case of a real gas, the intermolecular forces and the size of gas molecules themselves resist compression, leading to a larger volume occupied by the gas at high pressures.

4. Conclusion:
In conclusion, at very high pressures, a real gas occupies a larger volume compared to an ideal gas. This is because real gases experience intermolecular forces and have a finite molecular size, which prevents them from being compressed as easily as ideal gases. The behavior of real gases at high pressures deviates from the predictions of the ideal gas law.