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Topic: Making a buffer solution  (Read 1843 times)

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Offline Capital

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Making a buffer solution
« on: March 28, 2011, 01:14:14 AM »
A scientist wants a buffer solution that will work at a pH level of 3.75.
a)Which weak acid and conjugate base will work?

b) What will happen to the pH if a few drops of NaOH was added to this buffer? Would the pH change? If so, how much, would it increase or decrease?

My answer:

a) My thinking is that any weak acid will work because only strong acids can't form buffer solutions. Which makes me think my thinking is wrong because then the question will seem pointless as any weak acid would be correct. So is my thinking correct?

b) Adding a base would cause the pH to increase. Since it is a buffer system, it would decrease slightly. Am I right? How do I know whether adding the NaOH will exceed the limitations of the buffer so the pH increases by a lot (not slightly)?

« Last Edit: March 28, 2011, 01:31:06 AM by Capital »

Offline AWK

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Re: Making a buffer solution
« Reply #1 on: March 28, 2011, 04:17:14 AM »
a) What pKa should have acid to get buffer best working around pH 3.75?

b)If so, how much, would it increase or decrease?
Read something on buffer capacity

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