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Old Apr 2nd 2018, 12:23 PM   #2
chemsurvival
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Hi Yjee,

The first step in your problem will be to decide on exactly which solutions to combine for each buffer. We usually prepare buffers by mixing solutions of conjugate acids and bases in differing proportions, so ammonia and ammonium mixtures make good buffers in certain situations while ethanoic acid and ethanoate might mix to make a good buffer in others.

Generally speaking, buffers are most effective when the pKa of the conjugate acid is close to the buffering pH. With that in mind and the following information, which two solutions do you think you need to use to make the pH 8.8 buffer? How about the pH 5.2 buffer?

ammonium pKa = 9.2

ethanoic acid pKa = 4.8

Eagerly awaiting your replies!

Professor Davis
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