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Author Topic: tricky q for me & for you? ??  (Read 855 times)  Share 

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lacoste

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tricky q for me & for you? ??
« on: March 16, 2009, 10:57:33 pm »
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Q27.
The amount of vitamin C in fruit juice can be determined by titration with a standard 0.0100 M iodine solution:
C6H8O6(aq) + I2(aq) -------> C6H6O6(aq) + 2H+(aq) + 2I–(aq)
If the maximum concentration of vitamin C is likely to be 0.00050 g mL–1, describe how you would perform the analysis. You should mention:
•   the volume of fruit juice used
•   the maximum titre of iodine you would expect to obtain.


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lacoste

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Re: tricky q for me & for you? ??
« Reply #1 on: March 16, 2009, 10:58:48 pm »
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dont describe analysis, i already got it but no idea about

•   the volume of fruit juice used
•   the maximum titre of iodine you would expect to obtain.


is what the/help please
« Last Edit: March 16, 2009, 11:21:34 pm by lacoste »

TrueTears

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Re: tricky q for me & for you? ??
« Reply #2 on: March 17, 2009, 11:09:07 am »
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1. Fill the burette with iodine solution. Record intial volume.
2. Pipette 20 mL of fruit juice into a conical flask.
3. Add 2-3 drops of starch indicator to fruit juice.
4. Titrate until endpoint is reached, recording final volume.
5. Repeat steps 1-4 until three concordant tires within 0.10mL of each other are obtained.

Since the concentration of vitamin C is , in about 20mL of fruit juice (you could also have other volumes of fruit juice, but I choose 20mL) there is 0.01g of vitamin C.







So the expected titre is about 5.86mL
PhD @ MIT (Economics).

Interested in asset pricing, econometrics, and social choice theory.