What bonds or forces are broken when ethanol is vaporized?

Question

Ethanol has covalent bonds, hydrogen bonds, and van der waals' forces

Answer 1

Covalent bonds are not broken - they are the bonds between the individual atoms, and intermolecular forces are broken apart in vaporization, not intramolecular forces (what holds a molecule together.)

So: van der waals forces are weak forces that attract molecules to each other.  They are caused because electrons move randomly, and therefore there is bound to be an uneven concentration of charge sometimes.  That causes a dipole to form on all the molecules close enough to feel that irregularity.  Even though these irregularities are quickly corrected, it spreads along all the molecules - kind of like a chain reaction. But these are very weak forces. So yes, when you vaporize ethanol, you break van der waals forces.

Hydrogen bonds are strong dipole forces between hydrogen, an electropositive atom,  and an very electronegative atom with concentrated charge like N, O, and F (pretty much nothing else counts.)  Since ethanol has and O and it has the H, and it is in a good enough shape that the O of one molecule and H of another can "fit together" and have room to have good attraction, there are hydrogen bonds in ethanol, though not to extent that water has, and hydrogen bonds are broken when ethanol is vaporized.