[propionaldehyde]

I just need a little help in determining (generally, when comparing similar molecules) which functional groups would have higher boiling points than others. This isn't homework, it's just for study purposes. I've tried creating a list, but I'm not quite sure where some functional groups go. Like aldehydes, ketones, esters, ethers, alkenes, and aromatic rings.

Here's what I have so far:

amides > carboxylic acids > alcohols > ketones > aldehydes > amines > esters > ethers > benzene > cycloalkanes > alkynes > internal alkenes > alkanes > terminal alkenes


Is this list accurate?

[dunno260]

I am not sure what the utility of the list would be in all fairness.  In general, the more polar a group is (of compounds with similar structure and MW), the higher the boiling point.  You might get a decent idea of this by comparing monosubstituted benzene rings with some small functional groups but its not going to tell you much anyways, and when you get down in the list to compounds with little polarity such as alkynes, alkenes, and alkanes your probably not going to see a ton of difference.  For instance compare the boiling points of benzene and cyclohexane and then compare the boiling points of decalin and napthalene.

So why do you want to make such a list?

[propionaldehyde]

Well, to be honest I'm making a list (and checking it twice! ) because I have a test coming up. More specifically, the ACS. And I'm sure they'll be asking for boiling points. I'm trying to have very strong fundamentals here.


You're right, though. There are a lot of things to take into account when comparing the boiling point of different compounds, and making a list would never truly give a right answer because of many exceptions. However, this is just so I can have a very general idea. If I know which ones have higher boiling points most of the time, I can start to think of why, when and also how they are affected by other groups.


Thanks for answering!