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    My book says that lower members of the homologous series of alkylamines are gases and volatile liquids hencr methylamine is a gas. I do not understand. I expected that methylamine would be Solid because of hydrogen bonds existing between the molecule of compound(due to amine group). Below the series would be gases and liquids because the percentage of hydrocarbon group increase which lessens the affect of the amine group to form hydrogen bonds between molecules. Please correct me, where have I gone wrong in my thinking process?
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    (Original post by Ameera98)
    My book says that lower members of the homologous series of alkylamines are gases and volatile liquids hencr methylamine is a gas. I do not understand. I expected that methylamine would be Solid because of hydrogen bonds existing between the molecule of compound(due to amine group). Below the series would be gases and liquids because the percentage of hydrocarbon group increase which lessens the affect of the amine group to form hydrogen bonds between molecules. Please correct me, where have I gone wrong in my thinking process?

    The longer the hydrocarbon chain, the greater the number of van der waals forces between molecules. So compare CH3NH2 (methylamine) to CH3CH2CH2CH2NH2 (butylamine)

    Both alkylamines form hydrogen bonding, but butylamine can form more and stronger van der waals forces than methylamine. This increases the intermolecular forces between the molecules which increases the boiling point.

    That's why at room temp, methylamine is a gas, and butylamine is a liquid.
 
 
 
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