Berapakah ph jika 100 ml HCl 0,5 M dicampur 200 ml NH3 0,5M dan kb =10`5

mol HCl = 0.5x 100 = 50 mmol
mol NH3 = 0.5 x 200 = 100 mmol

......HCl + NH3 => NH4Cl
m...50.......100
r....-50.......-50..............+50
s....-..............50...............50

sisa basa lemah => penyangga
OH- = Kb x Cb/Cg = 10^-5 x 50/50 = 10^-5
pOH = 5
pH = 14-5 = 9