Intermolecular force and MP

[drill-and-fill]

DAT destroyer orgo question # 206 states that 2,2 dimethyl propane would have a higher MP than pentane due to more branching and symmetry. However, doesn't intermolecular forces affect MP? I figured pentane would have a higher MP since it's more linear, has more surface area hence bigger london dispersion force, which ultimately leads to higher overall intermolecular force and higher MP... Can someone please shed some light on this... Im really confused.

Do I ignore intermolecular force when trying to determine MP and compare branching instead?

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[Mr. Thirsty]

When it comes to branching, mp is opposite of bp. More branching = more surface area = lower boiling point = higher mp. Its a different comparison than intermolecular forces.

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[LSDP]

branching compound has higher MP because it can pack into a crystal better because of higher surface area.

Doop, I should of drawn the linear one longer because now the branched ones look longer.

 

[drill-and-fill]

Thanks guys, lol really loving the figure