[tim__jones]

Hi

I would really appreciated help with this problem I have...

I have a solution of H2SO4, ph 3.2, molarity 0.0006326309 M. I need to know what the molar concentration of SO4 is in this solution.

Then I need to make up a solution of NaOH with the exact same molar concentration of OH ions as the molar concentration of SO4 ions in the H2SO4 solution.

It would be greatly appreciated if someone could someone advise me what molarity or pH the solution of NaOH would have to be for this?

Many thanks.

Tim

[Borek]

I have a solution of H2SO4, ph 3.2, molarity 0.0006326309 M.

Contradicting information. 6*10^-4M sulfuric acid has pH below 3.

[tim__jones]

According to this website the pH of 6x10-4 H2SO4 is 3.2:

http://www.sensorex.com/support/education/pH_calculator.html

[Yarr]

Then that website is wrong: the pH of H2SO4 0.000633 M is 2.92 (apprx.).

[Borek]

According to this website the pH of 6x10-4 H2SO4 is 3.2:

It gives pH of 0.0001 sulfuric acid as 4, obviously wrong.

2.92 - ignoring ionic strength of the solution, 2.94 - taking IS into account.

[Yarr]

Borek, I have a question for you: in some sources the pKa of HSO4- ion is given as, 1.92, while you and other sources give it as 1.99. What is the true value?

[Borek]

All I can tell you is what source I have used - Handbook of Chemical Equilibria in Analytical Chemistry, Kotrly and Sucha, Ellis Horwood Ltd. 1985). They claim to use value listed in Critical Stability Constants, vol. 4 Inorganic Complexes, RMSmith and AEMartell, Plenum Press, NY 1976. What is a correct value I have no idea 

[Yarr]

Ok thanks.