Calculate the pH of a 5.20 10-3 M solution of H2SO4.
How difficult is this course supposed to be? H2SO4 is a strong acid for the first ionization; therefore, that will be 0.00520M. To that, if you wish to be accurate, is added the H^+ contribution of the second ionization, which is relatively strong, but still a weak acid. k2 in my text is listed as 0.012 but you should confirm that from your text.
HSO4^- ==> H^+ + HSO4^-
k2 = (H^+)(SO4^-2)/(HSO4^-)
So the (H^+) is 0.00520 + x and the HSO4^- is 0.00520 - x. You can set that up and solve the quadratic to find x, then 0.0052 + x is H^+. Then convert that to pH.