Group Work
What is the pH of 1.00 M HF solution? Ka = 7.0 x 10- 4
HF H3O+ F-
Initial 1.00 0 0
Change -x +x +x
Equil. 1.00 - x x x
x2/(1.00 - x) = 7.0 x 10- 4
Assume x << 1.00: x2/1.00 = 7.0 x 10- 4
x = 2.65 x 10-2, so the assumption was okay
pH = -log(2.65 x 10-2) = 1.576