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Topic: Ion-product constant of Water  (Read 1611 times)

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Offline treadlightly

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Ion-product constant of Water
« on: January 26, 2014, 06:00:23 PM »
So I am currently confused on a homework problem. The problem at hand says "How much will pH increase if you add 1 mL of 1M KOH to a liter of water?"

I'm pretty sure I have to use the ion-product constant of water for this question. I set up an equation like this: [H+] = Kw/[OH-] = (10^-14)/(.001) = 10^-11, which means that my pH will increase to 11. I'm quite sure I made an error somewhere, because I don't understand how one 1-mL drop of KOH can increase the pH of a liter of water so quickly. Can someone help me out here?

Offline Borek

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Re: Ion-product constant of Water
« Reply #1 on: January 26, 2014, 06:09:02 PM »
If it doesn't say anything about initial pH (and solution composition), it is impossible to answer, unless you assume initial pH to be 7.

If the initial pH was 7 pH increased to 11, but not BY 11.

11 is a correct value BTW.
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