Question

What is the force of intermolecular attraction that operates in ethanol?

Answer 1

The dominant intermolecular force that operates in ethanol is `"hydrogen bonding."`

Explanation:

The normal boiling point of ethane, `H_3C-CH_3`, is `-89` `""^@`. The normal boiling point of ethanol, `H_3C-CH_3`, is `78.1` `""^@`. As in water, hydrogen bonding occurs between the protic hydrogen and the electronegative oxygen atoms on adjacent ethanol molecules, i.e. `H_3C-CH_2O^(delta-)-H^(delta+)`, and this constitutes a potent intermolecular force.

See [here for another description of the phenomenon.](https://socratic.org/questions/describe-a-hydrogen-bond-what-conditions-must-exist-for-a-hydrogen-bond-to-form?source=search)