Victor K. answered • 11/29/16
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Consider the dissociation equation for the carbonic acid:
H2CO3 → H+ + HCO3-
You'll need to construct an ICE table for this question and put the result into the Ka equation and solve it for [H+]. Ka for carbonic acid is 4.5*10-7. The second Ka is negligibly small to be significant here.
Ka = [H+][HCO3-]/[H2CO3]
If you do everything correctly you should get your pH≈3.
Porcia C.
I thought ka=4.2*10^-7
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11/29/16
Victor K.
Well, how about you write up what you have, and I'd be happy to look over it and let you know if there are any errors.
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11/29/16
Victor K.
and Ka varies slightly depending on the reference. It's not going to make much difference here in any case.
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11/29/16
Porcia C.
11/29/16