Jawabanmu

2014-02-28T20:20:04+07:00
Reaksi yg terjadi:
Ca(OH)2 + HCl ---> CaCl2 + H2O

mol Ca(OH)2 = gr/Mr = 4/74 = 0,05mol
[Ca(OH)2] = mol/V = 0,05mol/0,1L = 0,5M
[OH]- = 1M

prinsip penetralan: 
V1n1 = V2n2
25mL . 1M = V2 . 0,2M
V2 = 25/0,2
V2 = 125mL