LDF vs Hydrogen Bonds

[Sophia_Patrick]

How long would a hydrocarbon have to be for its London dispersion forces to be greater than hydrogen bonds?

[306432459]

Hydrogen bonds will always be stronger, unless its like a super long carbon chain, typically more than 10 carbons.

[Gordon Standing]

Depending on the molecule's molecular size/shape and surface area, the hydrocarbon would have to be 10-12 carbons long to equal the strength of H-bonds and around 16-20 carbon atoms to undoubtedly surpass the strength of the H-Bonds. Also understand that this estimate is subject to change due to changes in other factors, like temperature for example.

Hope this is helpful.