Hitunglah pH larutan 500mL HCN 0,1 M yang dicampur dengan 500mL KOH 0,1 M (Ka HCN = [tex] 10^{-6} [/tex])

Molaritas=mol/volume
Mol=M×volume
Mol HCN 500×0.1= 50
Mol KOH 500×0.1= 50

HCN + KOH -> KCN + H2O
M 50 50 - -
R 50 50 (-) 50 50 (+)
S. - - 50 50

Molaritas KCN = mol/voltotal
=50/500+500
=50/1000 = 0,05

pOH = √kw/Kamu
= √10^-14/10^-6×0,05
= 2,23× 10^-5
= 5 - log 2,23
pH = 14-(5-log 2,23)
= 11 + log √5