[University - Chemistry] Intermolecular Forces

[sumzup]

Ok, so on a recent midterm we were asked to order 5 compounds by strength of intermolecular forces from least to greatest.

The compounds were: CCl4, CH3OH, CO, Ne, and CH4.

The way I ordered it when I took the exam was: Ne < CO < CH4 < CCl4 < CH3OH, and this turned out to be correct (and now I'm confused as to why it is; my logic at the time of the test left me right after I finished, it seems).

My reasoning: Ne only has Induced Dipole - Induced Dipole forces, so it's lowest, CH3OH has hydrogen bonds and therefore is highest, and CCl4 has a large molar mass and is therefore right below CH3OH.

What I can't figure out, though, is why CO has weaker intermolecular forces than CH4. CO has a higher molar mass, and has polar covalent bonding which lead to Dipole - Induced Dipole forces; CH4 only has Induced Dipole - Induced Dipole forces. Actually, for that matter, why is CH4 greater than Ne?

Crap, I've confused myself. Someone please enlighten me.