If a solution of HF (Ka = 6.8 10-4) has a pH of 3.42, calculate the total concentration of hydrofluoric acid.

2 answers

pH = 3.42.
3.42 = -log(H^+)
(H^+) = 3.80
E-4
...........HF ==> H^+ + F^-
initial....x.......0.....0
change.....................
equil...x-3.8E-4..3.8E-4..3.8E-4

Ka = (H^+)(F^-)/(HF)
Substitute from the ICE chart above and solve for x.
no