Question

What are the concentrations of HSO4- and SO42- for a 0.0050 M sulfuric acid solution?

We are trying to find x but not sure how to find it on the calculator, please help!!!

Answer 1

..........H2SO4 ==> H^+ + HSO4^-
I........0.0050M....0......0
C.......-0.005...0.005...0.005
E..........0.....0.005...0.005

So for the first ionization, H^+ = 0.005M and HSO4^- = 0.005M. Then HSO4^- goes through k2.
........HSO4^- ==> H^+ + SO4^2-
I.....0.005M....0.005....0
C........-x.........x....x
E.....0.005-x...0.005+x...x

k2 = (H^+)(SO4^2-)/(HSO4^-)
0.012 = (0.005+x)(x)/(0.005-x)
I used k2 from memory; I suggest you look it up in your text and use that. Then simply solve the quadratic equation. Or you can solve it by reiteration.