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    • Thread Starter

    Hey everyone, just wondering if somebody can help me out with the following:

    For my AH Chemistry project I want to research Vitamin C degredation in various fruit juices and conditions, however, I'm having a little trouble with one of my methods:

    I want to try using DCPIP (2,6-dichlorophenol indophenol) to determine Vitamin C concentrations, but i'm having alot of trouble with a couple of things:

    1- Finding the (a) correct method (I'm not sure about determining the end point, and I'll probably be using a 1% DCPIP solution and, for testing the method, 1% Vitamin C solution as well)

    2- Finding a balanced equation for the reaction which takes place between DCPIP and Vitamin C so I can determine concentration(s) at the end of the reaction

    p.s posted this on both Chemistry and Biology sections because it's a bit of both
    Please reply here or send me a pm if you can help me out, thanks alot!

    1.I can find a basic method for the type of thing you mean:

    Basically, you'll have your measured fruit juice. And titrate a concentration of DCPIP into it. When it's titrated you should be able to work out the volume of DCPIP solution used. With this knowledge, and the molarity of the DCPIP, you can calculate the number of molecules/moles of DCPIP used, and thereby calculate moles/molecules of Vit. C. With the moles of Vit. C, and the initial volume of juice you can calculate the molarity of the fruit juice.

    You'll definitely need to test with 1% Vitamin C. Even if just to note the end point, might be useful to have on hand when you do the experiment proper, for comparison. You'll also need to work out the ball park concentration of Vit C, so if necessary, you can refine the concentration of DCPIP to use, since you don't want just one drop of DCPIP to react with all the Vit. C in juice.

    2. http://www.chemistry-react.org/go/de...Faq_10918.html
    1 mole DCPIP to 1 mole Vit C
    You can double check using the 1% DCPIP, 1% Vit. C test.

    I strongly recommend reading all the relevant links on this website:
    It might help you with your other experiments too!
    Make sure you note a reference for every method and piece of information you collect in research. This will aid in the write up.
    • Thread Starter

    Thanks alot! this makes my life alot easier
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