is tpr wrong for a whole chapter? mp/bp in mcat hyper learning

[wall1two]

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the sentence "branching of a hydrocarbon decreases BOTH MP and BP" is stated about 100 times in their biological sciences hyper-learning book.
"...branching tends to decrease intermolecular forces between molecules leading to a decreased melting and boiling point"

from what i understand branching decreases bp because surface tension is decreased and more molecules and reach the surface with greater ease.

branching (symmetrical branching esp) increases MP because they can stack tighter.t

if I, chad, and 99% of the internet is correct, shame on the princeton review.

 

[tendram]

Yeah I'm pretty sure that's wrong. The general rule of thumb is that the larger the molecule the higher the melting point and thus increasing boiling point. I mean with larger molecules especially hydrocarbons you are going to see quite a bit of Van der Waals interactions thus making the compound pretty "compact" and harder to break up. Thats kind of odd they left that unnoticed and in an MCAT book of all places.