You have been asked to prepare a buffer of pH 3.20 and have only two reagents available. The first is 500.00 mL of .1 M acetic acid and the other is a jar containing 100 g of KOH (Ka=1.8x10^-5
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That's not too bad. Just use the Henderson-Hasselbalch equation. pH = pKa + log([A-]/[HA]) You've got the desired pH and the pKa (pKa = -log(Ka)), so you can solve for the ratio of [A-]/[HA]. Once you've got that, you have the molarity of [HA] (acetic acid). Using the required molarity of KOH ([A-]) and the volume 200 mL, you can get how many moles of KOH salt you need and subsequently, the mass.
But I think that KOH and acetic acid don't even form a buffer solution. Conventionally, don't you use an acid and its conjugate base in a buffer solution?
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fucking bitchez they set you up for failure!
at least we're all on the same page
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pH = pKa + log([A-]/[HA])
You've got the desired pH and the pKa (pKa = -log(Ka)), so you can solve for the ratio of [A-]/[HA]. Once you've got that, you have the molarity of [HA] (acetic acid). Using the required molarity of KOH ([A-]) and the volume 200 mL, you can get how many moles of KOH salt you need and subsequently, the mass.
But I think that KOH and acetic acid don't even form a buffer solution. Conventionally, don't you use an acid and its conjugate base in a buffer solution?
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you really are smart.
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WHOOP THAT TRICK.
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