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Topic: Strong Base and weak acid  (Read 3924 times)

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Offline CopperSmurf

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Strong Base and weak acid
« on: April 04, 2008, 06:07:21 PM »
Hi. I'm forgetting how to do the basics now. If I added a strong base to a weak acid and if I add enough strong base, then the OH- from the strong base would neutralize all of the weak acid correct? If I continue to add more strong base, would the pH rise solely on the strong base? like, all of the H+ would be gone, so, would I treat this like a buffer problem? Or just determine the pH from the pOH of the strong base after the equivalence point? I'm just trying to find the pH..

Help clear my head please?

Offline Borek

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Re: Strong Base and weak acid
« Reply #1 on: April 04, 2008, 06:37:41 PM »
If I added a strong base to a weak acid and if I add enough strong base, then the OH- from the strong base would neutralize all of the weak acid correct?

Yes, assuming enough means excess. If it means stoichiometric amount pH is determined by the hydrolysis of the conjugated base. If it means less then stoichiometric you may assume weak acid was stoichiometrically neutralized.

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If I continue to add more strong base, would the pH rise solely on the strong base?


Yes.

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like, all of the H+ would be gone, so, would I treat this like a buffer problem?

No. You are contradicting yourself. If the pH changes only because of the excess strong base, it is no longer a buffer problem. It is just strong base.

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Or just determine the pH from the pOH of the strong base after the equivalence point?

Yes.
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Offline CopperSmurf

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Re: Strong Base and weak acid
« Reply #2 on: April 04, 2008, 11:37:00 PM »
cool thanks a ton Borek. Snack for you :)

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