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Topic: Buffer solution  (Read 3430 times)

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Offline angst

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Buffer solution
« on: July 25, 2007, 10:27:28 PM »
Hi, I have a question about buffer solution NH4Cl+NH4OH. Can I know what is the ratio of this buffer solution?

What is the method to determine the ratio?

May I know the pH value of this buffer solution?

Thanks.

Offline enahs

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Re: Buffer solution
« Reply #1 on: July 25, 2007, 10:33:19 PM »
The pH depends on the ratio. The ratio depend on the pH. However you want to look at it.

The ratio and there for the pH depends on how much of the acid and conjugate base you have.


http://en.wikipedia.org/wiki/Henderson-Hasselbalch_equation

Offline sdekivit

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Re: Buffer solution
« Reply #2 on: July 26, 2007, 04:37:34 AM »
in any case, when [acid] = [conjugated base] then pH of the buffer equals pKa and the solution will have buffer capacity in the range (pKa - 1) to (pKa + 1)

Offline profmsg

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Re: Buffer solution
« Reply #3 on: July 28, 2007, 06:19:56 AM »
your buffer is made up of  NH4Cl+NH4OH and i agree with  sdekivit if no Ph is altered.

but must of the buffers are made in certain ratio with certain solvent then adjusted ph using  other chemical such as orthophosphoric acid.
so with the ratio of sovents, it is not possible to determine the ph of that buffer


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