Calculating pH of Polyprotic Acids
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Calculating pH of Polyprotic Acids
Outline 2: Acids and Bases, and in the textbook section 6E.1 state that if the second Ka value is less that the first Ka value divided by 1000, we can consider only the first deprotonation of the polyprotic acid as significant, and find the pH of the acid using the ICE table. However, in the case that KA2 is NOT less than about KA1/1000, how should we go about finding the pH of the polyprotic acid?
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Re: Calculating pH of Polyprotic Acids
I believe in that case, you would have to do multiple calculations and add the concentrations of H+. Using H2SO4 as an example, you would find the concentrations of HSO4- and H+, and then from there find the concentrations of SO42- and H+. You would sum up the total H+ concentration from both these to calculate pH.
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Re: Calculating pH of Polyprotic Acids
Adding on, I believe the outline said that only H2SO4 should be treated this way, all other polyprotic acids should just be treated as a weak monoprotic acid since their subsequent dissociations are so weak that they don't contribute to the pH
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