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Homework Help: Determination of Vitamin C

  1. Oct 28, 2007 #1
    [SOLVED] Determination of Vitamin C

    I'm a little stuck on getting started on the calculations of a recent redox titration lab that I did, and was wondering if anybody could help me out.

    First I dissolved a 250 mg tablet of vitamin c in 50 mL distilled water.

    Then, I prepared a buret with 0.002034M KIO3 solution

    Next, I pipetted 5.00 mL of the vitamin c solution into a flask and added 5 mL of 0.6M KI solution, 5 mL of 1M HCl, 1 mL startch indicator solution.

    The endpoint was reached after 11.27 mL of KIO3 was titrated into solution.

    The question that I'm having trouble with is: From the volume of titrant added, calculate the moles of vitamin C for each titration.

    I know the molarity of KIO3 is 0.002034 mol/L.

    Therefore, M=n/v

    n=2.2923 x 10^-5

    Would this also be the amount of moles of vitamin c? Or am I way off base? Can anybody please lead me in the right direction?
  2. jcsd
  3. Oct 28, 2007 #2
    you need to balance the redox equation for IO3- + I- ---> I2

    and how does the vitamin C reaction with these chemicals?
  4. Oct 29, 2007 #3
    Thanks for the reply eli. Yeah, I just noticed the two reaction equations hidden in the lab manual just after I posted.
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