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I know that when comparing between these three families, alkynes have the highest MP and BP, followed by alkanes and, lastly alkenes (when comparing the same number of carbons).

I know alkynes "win" because of the triple bond (pulling the carbons tightly together, etc. I also know the alkynes have the least number of dispersion forces.

So, how come when comparing alkanes to alkenes, the number of dispersion forces "wins out" in determining MP and BP and not the double bond (which also pulls tighter than a single C-C bond)...but with alkynes, the triple bond can "beat out" the decreased number of dispersion forces?


marked as duplicate by Mithoron, airhuff, aventurin, Tyberius, Waylander May 22 '18 at 19:18

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