Jawabanmu

2014-04-24T00:04:13+07:00
Bereaksi = OH= akar (10^-14 . 0,4 / 10^-5 )
               OH = akar (4 x 10^-10)
               OH = 2 x 10^-5
a = 2 x 10^-5 . 100 % / 4 x 10^-1 = 0,005