Jawabanmu

2014-04-08T19:01:54+07:00
PH = 9
pOH = 14-9
       = 5
[OH-] = 10^-5
[OH-] = Kb.M NH4OH/M NH4Cl.2
10^-5 = 2x10^-5.10^-1/2M
2x10^-5 M = 2x10^-6
             M = 2x10^-6/2x10^-5
                 = 10^-1
                 = 0,1 M