Suppose you want to do a physiological experiment that calls for a pH 6.5 buffer. You find that the organism with which you are working is not sensitive to the weak acid H2X (Ka1= 2x10^2, Ka2= 5.0x10^-7) or its sodium salts. You have available a 1.0 M solution of this acid and a 1.0 M solution of NaOH. How much NaOH solution should be added to 1.0L of the acid to give a buffer with a pH of 6.5? (Ignore any volume change do to the addition of NaOH)

Please help this is an extra credit for a test i miserably failed and im getting a chance to redo it! I will give all points if shown the correct stephs. Im assuming this is close to a titration problem? not sure!