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# Working out pKa from titration curve graph

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1. I hve a book(http://www.amazon.co.uk/Calculations.../dp/0582411270) that says that you can work out the pH and pKa from a titration curve.
It says all this stuff about how pKa and pH are equal and you need to half the volume...I have no idea what it means!
Help
2. Before you get the neutralisation point, adding aicd/alkali doesn't do much, as it is a buffer solution.
This also means that [HA]=[A-]
leaving Ka=[H+] in the acid equation
getting -logKa=-log[H+]
which is pka=pH
3. (Original post by lamalas600)
Before you get the neutralisation point, adding aicd/alkali doesn't do much, as it is a buffer solution.
This also means that [HA]=[A-]
leaving Ka=[H+] in the acid equation
getting -logKa=-log[H+]
which is pka=pH
huh?
4. Maybe I'm awful at explaining... lol what don't you understand from that?
5. Confusion number 1 how'd you know it's a buffer solution?
6. When you do a titration, there are no changes at all until a sudden colour change, this means that the pH isn't changing that much when your adding alkali/acid, until the neutralisation point.
Buffer - Resists changes in pH when small amounts of acid/alkali are added to it.
7. (Original post by lamalas600)
When you do a titration, there are no changes at all until a sudden colour change, this means that the pH isn't changing that much when your adding alkali/acid, until the neutralisation point.
Buffer - Resists changes in pH when small amounts of acid/alkali are added to it.
So it acts as a buffer until the equivalence point (or is it the end point)?
8. (Original post by The Illuminati)
So it acts as a buffer until the equivalence point (or is it the end point)?
Yes, and equivalence point and end point are the same thing

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