Ka.HCN=4,7×10^–10.
2,7 gram HCN (Mr. HCN = 27) dilarutkan dalam 100 ml larutan. Hitunglah konsentrasi ion H+
5.4 gram HCN
Mr = 27
mol = 5.4 / 27 = 0.2 mol = 200 mmol
volume = 100 ml
Molaritas = mol / volume
= 200 / 100
= 2 M
Ka = 4.7 x 10⁻¹⁰
[H⁺] = sqrt{Ka.M}
Ka.M
= sqrt{4,7. 10^{-10}.2 }
4,7.10
−10
.2
= 3,06 x 10⁻⁵
pH = 5 – log 3,06