Solving for polyprotic acids and bases
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Solving for polyprotic acids and bases
When solving for the equilibrium concentrations of polyprotic acids and bases, do we always have to break them into individual protonations of one H+ ion released / gained for each reaction and use the Ka1, Ka1, etc.?
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Re: Solving for polyprotic acids and bases
I think so; this method seems to work to organize the equations and show the ionization stepwise. For example, polyprotic acids like H3PO4, H2PO4-, and HPO4(2-) will always show that each ionization step is more difficult, since it's more difficult to remove H+ from a molecule as its negative charge increases. Doing the step method will show us that, with
Ka1>Ka2>Ka3
Ka1>Ka2>Ka3
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Re: Solving for polyprotic acids and bases
I believe so. And to find the overall K of the reactions, we would just multiply the K values we found.
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Re: Solving for polyprotic acids and bases
Yeah, I think that we need to break the reactions down into individual protonations.
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Re: Solving for polyprotic acids and bases
Yes, from what I understood from the textbook, it doesn't seem like we would need to use anything more than the first protonation for a lot of them since the later ones are negligible but that would be the easiest way to solve it if you do have to use the other values.
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