Question

At high pressures how does the volume of a real gas compare with the volume of an ideal gas under the same conditions and why

Answer 1

Answer: No, at high pressures, volume of a real gas does not  compare with the volume of an ideal gas under the same conditions.

Reason: 
For an ideal gas, there should not be any intermolecular forces of interaction. However, for real gases there are intermolecular forces of interaction like dipole-dipole and dipole-induced dipole. Further, at high pressures, molecules are close by. Hence, extend of these intermolecular forces is expected to be high. This results in decreases in volume of real gas. Thus, volume of a real gas does not  compare with the volume of an ideal gas under the same conditions.

Answer 2

Answer:

At high pressure, volume of a real gas is lower than volume of an ideal gas under the same condition

Explanation:

At high pressure, total volume of gas molecules are no longer negligible as compared to volume of gas or more precisely volume of gas container.

For ideal gases, gas molecules are assumed to be point masses. That means, ideal gas molecules do not have measurable volumes.

But, in real gases, gas molecules have small but measurable volume.

At low pressure, volume a gas is so high that volume of gas molecules are neglected. Hence real gases behaves ideally at low pressure.

But, at high pressure, actual volume of a gas should be volume of gas container minus volume of gas molecules.

hence volume of a real gas is lower than ideal gas at high pressure