What characterizes in general a basic solution is the presence of hydroxide ions, when adding a base to the water, the base B takes from the water molecule a proton H+, thus obtaining BH+ and OH-
B + H2O → BH+ +OH-
The same thing occurs with NH3: NH3 + H2O → NH4+ +OH-
but with NaOH it's different, we don't represent the water molecule in the equation, we just write:
NaOH → Na+ +OH-
What is the role of the water in this case, I know there's a phenomen of dilution, but there must be a proton exchange?
Actually we can write the same with NaOH NaOH+ H2O <=> NaOH2+ OH- (analogy with water 2H2O <=>H30+ + OH-) but it makes no sense . NH3 must get form NH4+ to be written in some compound, and Na must get Na+ Its just formalism and the reason of this is 1 atom of H, which is need to make some equation