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Alkanes physical properties help please

"For alkane liquids, this increase in intermolecular forces with increase in length of carbon chain, means they also become less volatile, less flammable and more viscous."

Can someone please further elaborate on and explain the reasons behind these changes?
Increase in chain length means there's an increase in the number of atoms.

ALL atoms exhibit Van Der Waals forces and the strength of VdW increases as the number of electrons increase. This is because there is a stronger induced dipole when the number of electrons is greater (read more into VdW if you don't understand how they work, CBA explaining).

Thus the more atoms there are, the stronger the overall VdW forces the alkane chain exhibits: INTERMOLECULAR forces (not INTRAMOLECULAR).
(edited 5 years ago)

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