posted by ryan .
how do you identify the base in this reaction?
h2o(L) + CH3NH2(aq) yields OH-(aq) + CH3+(aq)
I think that the base always contains hydroxide, aka OH; the original components were water mixed with an ammonium compound ( NH2)Check the chemistry reference tables too, which have tables that identify the bases and acids.
You have a typo, actually an omitted portion, in your post. You should have posted
H2O(l) + CH3NH2 ==> OH^- + CH3NH3^+
How do you know which is the base? If you go by the Arrhenius theory the base produces OH^- in solution. In this case it is easier, I think, to use the Bronsted-Lowry theory. The base is the one that takes a proton away from something. In this case, CH3NH2 took a proton away from H2O to form the CH3NH3^+.