Hitung pH xari 100mL larutan Ca(OH)2 0,025 M

Ca(OH)2 = 0,025 M
n Ca (OH)2= 0,025 M x 100 mL = 2,5 mmol
Ca(OH)2 => CA2+ + 2OH-
2,2mmol      2,5 mmol   5 mmol

[OH-] = 5 mmol/100 mL = 0,05 M

atau caracepat langsung
Ca(OH)2 => CA2+ + 2OH-
0,025 M                     0,05 M

pOH = -log [OH-] = -log [5 x10^-2] = 2- log 5 
pH = 14 -(2-log 5) = 12 + log 5