boiling point branching and stability

[spoog74]

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question;

i know branching on a molecule decreases surface area and subsequently decreases boiling point but im confused as to the stability of the molecule as a result of the higher branching. I was told that the more branching = the more stable... But wouldnt this be the opposite of what we should expect? Doesnt increased intermoleculer attractions ( more stable) increase boiling point? SO why does decreasing boiling point lead to greater stability then?

Maybe i just confused you all but i hope i make alteast a little sense

 

[FeralisExtremum]

More branching means less intermolecular forces overall. The molecule's branches prevent them from approaching as close together and packing as densely, so there are less dipole interactions.

Now, are branched alkanes more stable? Yes, in terms of the energy of their internal bonds. But when you're boiling a substance and causing a phase change, you aren't breaking the internal bonds - you're breaking the intermolecular bonds, the extent of which determine what state of matter you're in.