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Topic: calculating pH and hydronium ion concentration.  (Read 12103 times)

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Offline 2clients

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calculating pH and hydronium ion concentration.
« on: March 17, 2009, 05:21:48 PM »
Hello there,

I'm a little lost on this one:

Calculate the hydronium ion concentration and pH in a 0.5 M solution of NH4Cl.

I know pH = -log[H+], but I'm unsure how to find [H+].  Probably I need a Ka value for NH4Cl?

Any help is greatly appreciated!

David

Offline 2clients

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Re: calculating pH and hydronium ion concentration.
« Reply #1 on: March 17, 2009, 05:29:44 PM »
So after thinking about it more, I think an ICE table is appropriate here, and I could set (x^2)/(.5-x) = Ka of NH4Cl.

Solving for x will give [H+] and then I could take the negative log to get pH? I'm not finding the Ka value online...

Offline Borek

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Re: calculating pH and hydronium ion concentration.
« Reply #2 on: March 17, 2009, 06:13:40 PM »
NH4+ is a conjugate acid of a weak base.
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