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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: lacoste on March 16, 2009, 10:57:33 pm

Title: tricky q for me & for you? ??
Post by: lacoste on March 16, 2009, 10:57:33 pm

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.


THANKS!!!!!!!!!!!!!!!!!!!!!!!!!!

Title: Re: tricky q for me & for you? ??
Post by: lacoste on March 16, 2009, 10:58:48 pm

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

Title: Re: tricky q for me & for you? ??
Post by: TrueTears on March 17, 2009, 11:09:07 am

Quote from: /0 on January 18, 2009, 09:18:59 pm

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