Hi Nicole,

At high pressures gasses deviate from ideal behavior because the molecules are closer together which causes intermolecular forces that are not accounted for in ideal gas behavior. These forces would make the assumptions about real gasses incorrect - which is why they deviate from ideal behavior. A real gas should be under more pressure than an ideal gas because a real gas has a finite volume where as an ideal gas doesn't.

Hi Nicole,

These are two different concepts.

Real gases are different from ideal gases, in that in ideal gases, we assume that there is no attractive forces between atoms, when really, there are. This is why the pressure of real gases are slightly smaller than ideal.

Now, at high pressures, gases are "pushed" by the pressure to become more liquid, which is why at high pressures, gases become LESS ideal, and become "real". They can no longer say that in such a small amount of volume, that it the volume each gas particle takes up is negligible.

Hope this helps!

Molly