Question

How would we address the extent of intermolecular interaction for the series, air, ethanol, dimethyl ether, and carbon dioxide?

Answer 1

In terms of intermolecular forces of attraction:

`stackrel"Increasing intermolecular force; increasing normal boiling point.."rarr("Air, carbon dioxide, dimethyl ether, ethanol")`

This follows (inversely) the order of volatility.

Explanation:

And how do we know? Well, reasonably, intermolecular force may be correlated with boiling point. Elevated boiling points correspond to greater intermolecular interaction, and greater degrees of intermolecular force.

Air is a mixture of dioxygen, and dinitrogen, room temperature gases. Carbon dioxide sublimes at `-78.5` `""^@C`; dimethyl ether has a normal boiling point of `-24` `""^@C` (interestingly this stuff is pretty soluble in water...clearly its polarity is greater as compared to diethyl ether, which has minimal water solubility).

On the other hand, ethanol has a normal boiling point of `+78.0` `""^@C`, and this reflects the strength of hydrogen bonding, the which occurs when hydrogen is bound to a strongly electronegative element such as oxygen....and clearly hydrogen bonding also operates in water, a smaller molecule, yet one that is MORE involatile.