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Author: Subject: problems with calculations
andra
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problems with calculations

so I have to dissolve my substance (10mg) in 1% acetic acid at a conc of 0.2 wt.-% at pH=3.8. In how much acetic 1 % do I dissolve my sample?
SmashGlass
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It depends on the substance (?10mg of what?).
If the compound is not water soluble, I doubt you will ever get it dissolved.
Since this is obviously a homework exercise to improve your logic skills,
and since mine are already OK at this, you should really try to think this though yourself.
The crucial part is understanding the
wt-% conversion. (Weight percent).

None-the-less...

Is it correct to infer from your problem that you require the conc.
of your compound respective to the solution, you have
described, to be 0.2 wt-%? All other numbers are therefore extraneous.

Then you would require weight of your compound converted from mg into grams.
And the weight percent of each component in grams for the solution.
Since the weight of a very dilute acetic acid solution would be equivalent to
water, then you can work out the weight of your solution required.

Anymore than this and one may as well just write the answer for you,
and you would have learned nothing.

U2U if you are still stuck and need even more help.

[Edited on 25-10-2011 by SmashGlass]

If it ain't broke don't fix it....
Now where are my screwdrivers?

 Sciencemadness Discussion Board » Fundamentals » Beginnings » problems with calculations Select A Forum Fundamentals   » Chemistry in General   » Organic Chemistry   » Beginnings   » Responsible Practices   » Miscellaneous Engineering and Equipment   » Reagents and Apparatus Acquisition   » Electronics   » Process Engineering   » Materials and Metallurgy Special Topics   » Analytical Chemistry   » Electrochemistry   » Energetic Materials   » Biochemistry   » Radiochemistry   » Computational Models and Techniques Literature and Documentation   » Sciencemadness Wiki   » Prepublication Non-science   » Forum Matters   » Legal and Societal Issues