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Topic: Preparing solutions  (Read 4201 times)

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Offline yes

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Preparing solutions
« on: September 03, 2008, 06:27:52 PM »
The question is

"A solution is prepared by dissolving 10.8 g ammonium sulfate in enough water to make 100.0 mL of stock solution.  A 10.00 mL sample of this stock solution is added to 50.00 mL of water.  Calculate the concentration of ammonium ions and sulfate ions in the final solution."

Can anyone explain to me how to do it?  It's a question from my summer assignment for AP Chem, and I'm a little rusty (and I don't think we even covered that in track 2 chem last year =/)

Thanks!

Offline Borek

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Re: Preparing solutions
« Reply #1 on: September 03, 2008, 06:51:56 PM »
What part of the initial amount of ammonium sulfate makes its way to the final solution? What volume does this solution have?
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Offline yes

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Re: Preparing solutions
« Reply #2 on: September 03, 2008, 07:21:56 PM »
Well, the volume would be 60.00 mL, right?  And the volume of ammonium sulfate that is in the final solution is 10% of however much ammonium sulfate was used to make the initial 100.0 mL solution... how would I figure that out?

Offline Yggdrasil

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Re: Preparing solutions
« Reply #3 on: September 03, 2008, 08:56:13 PM »
A good starting point would be to write chemical formula for ammonium sulfate and find the molar mass.

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