[brasarehot]

I can't find online how to do titration problems with two bases. Here's my question...
What volume of 10M NaOH should be added to 1L of 0.5M sodium acetate pH 5 to change the pH to 6?

So here's what I'm thinking...
1) 5 = 4.76 + log(?/?)
2) 6= 4.76 + log(?/?)
3) Before NaOH addition [?] concentration = 0.5M
4) After NaOH addition [?] concentration = 0.5M + 10M = 10.5M

I don't know where to go from here. I also don't know what should go in the ? spaces.
If someone could explain to me how to understand and think about this problem or do the math steps it would be greatly appreciated. I have trouble figuring out what to isolate, what equation to use, how to approach problem, etc..
Titration problems seem so hard to figure out.
Or if someone has a website to recommend that shows the math that would be great too.

[Dan]

0.5M sodium acetate pH 5 to change the pH to 6?

This is confusing me. There must be something else is in the reaction mixture, sodium acetate (formula CH₃COONa) is a base. You cannot have an acidic solution of sodium acetate unless you have also added an acid, and the identity of that acid is needed to answer the question. Can you write out the question exactly as it's written in the original document?

By the way, NaCH₃COOH does not exist. CH₃COOH is acetic acid; CH₃COONa is sodium acetate.

[brasarehot]

Yes the question is written correctly. I'm sorry but my teacher gives us the hardest homework problems.

[Arkcon]

OK, the correct equation to use is Henderson-Hasselbach: http://www.chembuddy.com/?left=pH-calculation&right=pH-buffers-henderson-hasselbalch  Note that you have to decide which is the base, and which is the acid for that calculation.  And you must get it right.  In addition to the example Dan: noted, you also write Before and After NaOH concentration, when the text block mentions NaOAc is what is at 0.5 M, not NaOH.  See how I abbreviate it there?  Sodium acetate -- NaOAc, because when we do general chemistry pH experiments, all those carbons aren't going to react at all, so I give that part of the molecule a placeholder name.

[AWK]

Sodium acetate  is basic with pH ~8.8 for .1 M solution. hence for lowering pH you should add acid (eg HCl or acetic acid).
But 0.5 M acetate buffer containing 0.182 M CH₃COOH and ).318 M CH₃COONa shows pH close to 5. Then addition of NaOH can increase pH by 1.