Jawabanmu

2014-05-30T20:44:35+07:00
PH HCl :
pH = Ma.a
     = 0.002.1
     = 2 x 10^-3

2 x 10^-3 = akar Ka.Ma
              = akar 2 x 10^-5 . Ma
Ma = 4 x 10^-6/2 x 10^-5
      = 2 x 10^-1 atau 0.2M 
6 3 6