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cncbmb
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Homework Statement
We have two solutions: One solution that has [tex]0.300[/tex] L of [tex]0.100[/tex] M acetic acid, and the other with [tex]0.100[/tex] L of [tex]0.200[/tex] M [tex]CN^-[/tex].
We mix the two solutions. At equilibrium, what is the pH of the resulting solution?
Homework Equations
For acetic acid, [tex]K_a=1.8*10^{-5}[/tex]
For [tex]CN^-[/tex], [tex]K_b=2.5*10^{-5}[/tex]
The Attempt at a Solution
[tex]CH_3COOH + CN^- <=> CH_3COO- + HCN[/tex]...
The K values aren't useful here since there's no water in the reaction.
We can't assume the reaction goes to completion, in either direction since the acids and bases are weak. Not sure if solution is basic even though the [tex]K_b[/tex] for cyanide anion is greater than the [tex]K_a[/tex] of acetic acid since we have more acetic acid than base.
...
My textbook seems to dodge this issue in its explanation of "the reaction of a weak acid with a weak base." The textbook considers an equilmolar mixture of acetic acid and ammonia and says that the solution in that case would be neutral because the Ka of acetic acid the Kb of NH3 are the same.
Whoa why is the tex so thin?..