17.5 2 Acid-base reactions of amines Flashcards
solubility
primary amines are miscible with water but as hydrocarbon part of the molecule becomes larger solubility decreases
can from h bonds with water
how is methylamine basic and other amines
CH3NH2+H2O=CH3NH3+ OH-
Nitrogen atom can use lone pair of electrons to form a dative bond with the hydrogen of the water molecule
basicity
pKa
extending hydrocarbon chain causes futher but small increases in basicity
phenylamine very weak base
why is methylamine a stronger base than ammonia
methyl group is electron releasing increased electron density of nitrogen compared to nitrogen of ammonia
ethyl and propyl group slightly more electron releasing
why is phenylamine weak base
lone pair on nitrogen join lone pairs in the pi bond
make nitrogen less electron rich - part of delocalised system
lone pair of electrons less available for donating hydrogen of water molecule
less available ofr h bonding
methyl amine+strong acid
CH3NH3+ + NO3-
Methylammonium nitrate