Odpowiedź:
5.62%
Wyjaśnienie:
HF + H2O <=> H3O+ + F-
Ka = 0.00067
Co = 0.2 M
(Co/Ka = 298.5 < 400) => Ka = a^2 • Co / (1 - a)
a^2 • Co + a•Ka - Ka = 0
0.2a^2 + 0.00067a - 0.00067 =0
20000a^2 + 67a - 67 = 0
D = 5364489
a = 0.0562 = 5.62%
a - alfa
D - delta
