What intermolecular interactions occur for #"(i) dihydrogen"#, #"(ii) acetone"#, #"(iii) propane"#, and #"(iv) ammonia"#, #"(v) water"#, and #"(vi) hydrogen fluoride"#?

Can you rank these in order of volatility?

1 Answer
anor277
Jul 22, 2017

Well, van der Waals interactions occur for each set of molecules.....

Explanation:

But van der Waals interactions are weak, and thus dihydrogen, for which ONLY dipersion forces operate, is the MOST VOLATILE of the given substances, with a normal boiling point of #-253.9# #""^@C#. Propane, which also possesses minimal intermolecular interaction, is next cab off the volatility rank.

For acetone, there is some degree of dipole-dipole interaction, in that there is some polarity in the carbonyl bond, i.e. #stackrel(delta+)C=stackrel(delta-)O#; compare the boiling point of acetone, #56# #""^@C#, with that of propane, #-42# #""^@C#, the which only has dispersion forces operating.

For ammonia, hydrogen chloride, and water a special type of dipole-dipole interaction operates, #"hydrogen bonding"#, and this occurs where hydrogen binds to a strongly electronegative element such as oxygen, or fluorine, or nitrogen. You should look up the normal boiling points of #HF# and #NH_3#, and #H_2O#, and compare them to their lower group hydrides.

Related questions
See all questions in Intermolecular Bonds
Impact of this question
3439 views around the world
You can reuse this answer
Creative Commons License