Examples of calculating diprotic acid pH? And excess base Q.

[dekoyl]

Could someone provide me with an example of calculating the resultant pH of where a diprotic acid is added to some base? I just want to test my knowledge.
I can't seem to find one right now.
Thanks.

Also, how do we calculate the resulting PH an acid is added to a base that's in excess? ie. We end up with n(OH-) in excess? It's not simply [H+][OH-] = 10^-14 and we work out the [H+] from there, is it?

[dekoyl]

No one? =(

[/0]

For the second one you take excess. Then find pOH then pH if the conditions are right.

Not too sure about the first one (i.e. DONT TAKE MY WORD FOR IT), you would need to know the for the monoprotic form of the diprotic acid.

For example for the monoprotic form of sulfuric acid you would have



So in total you'd have

Then you find find excess mole of h+ or OH- then find pH or pOH or whatever

ALSO WHY THE HELL IS THE CLOCK ON THIS SITE ONE HOUR FAST
FUUUUUUUUUUUUUUU

[/0]

Thank god this didn't appear in the exam, I got it a bit wrong:

If you have a diprotic acid reacting with excess base it will fully ionise, donating two protons.

What I said applies when it ionises in water.