[kingwinner]

In general, which of the gases, N2, CO, and H2, would you expect to behave the most and least ideally?

I have no idea how to determine this...can someone help me? Thank you!

[biospy]

My teacher skipped this lesson for some odd reason on the gas laws, but mentioned that you would use Van der Waal's equation for such a thing

Try to learn about it..it might help:

http://en.wikipedia.org/wiki/Van_der_Waals_equation

[mike]

My guess would be H₂ would act the most like an ideal gas as it is the smallest and lightest.

Probably CO would be the least like an ideal gas as it is larger and heavier and it could be polarised (ie the C end is different to the O end).

[Yggdrasil]

The ideal gas equation makes two main assumptions which break down when talking about real gasses:

1) the ideal gas equation assumes that gas molecules take up no space, and
2) the ideal gas equation assumes that there are no intermolecular attractions/repulsions between gas molecules.

Therefore a more ideal gas would have small molecules and have small intermolecular forces, while molecules of a more non-ideal gas would have a large volume and have significant intermolecular forces.

So, I agree with mike's answer.  H₂ has a small molecular volume and has very small intermolecular forces (especially since dispersion forces decrease with molecular size).  CO, has a large molecular volume and its intermolecular forces are greater due to dipole-dipole interactions.

[billnotgatez]

Although not a choice by the original post, would Helium be the most ideal. I assume that we use the Ideal Gas concept because it approximates nearly enough for the your accuracy needs. Example -- When you have one cubic centimeter of gas do you care that you are off by millionth percent?

[Newton]

In general, which of the gases, N2, CO, and H2, would you expect to behave the most and least ideally?

I have no idea how to determine this...can someone help me? Thank you!

The main characteristic of ideal gas is that it cannot be liquefied

So the gas with lowest freezing point will resemble more like ideal gas eg H₂

The gas easily liquifiable eg CO will behave least as ideal gas.

Having said that ,at high Temperature and low Pressure,more or less all gases behave ideally.

[Borek]

The main characteristic of ideal gas is that it cannot be liquefied

Important, but IMHO that's not good way of stating what is the ideal gas characteristic, as it may be misleading.

Imagine a gas that can not be liquefied, but is pressurised so that molecules occupy 50% of the volume it has. Will it behave as ideal, or not?