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# Vitamin C individual project help!! watch

1. Hi,

I wondered if anyone can help me. So I have done a project on the vitamin C content within different concentrations of orange juice: Not-from concentrate, from concentrate and freshly squeezed, using a 0.1% Ascorbic acid as the control.(known concentration).

I have 2 days till I have to hand it in, and I cannot work out how to find the vitamin C concentration using the results I have obtained.

My experiment was using DCPIP (0.1%) and the results I have gathered shows the amount of orange juice needed to decolourise the DCPIP, How do i calculate the vitamin C content?

If anyone could help, you would be a lifesaver, I cannot find anything online!

Thank you!
2. You can plot a line graph from your 'known' concentrations if you have a range of known concentrations and use the graph to 'read' the 'unknown'.

Or if you only have the value for the 0.1% ascorbic acid...

You just need to know the relative volumes required to decolourise the DCPIP and multiply this by the concentration of the DCPIP.

For example, say it took 5.1cm^3 to decolourise the 0.1% ascorbic acid and 2.3cm^3 to decolourise the unknown orange juice.

(2.3/5.1) x0.1 = 0.045%

P.S I presume you did repeats so use your mean values....
3. (Original post by physio_sparkly)
You can plot a line graph from your 'known' concentrations if you have a range of known concentrations and use the graph to 'read' the 'unknown'.

Or if you only have the value for the 0.1% ascorbic acid...

You just need to know the relative volumes required to decolourise the DCPIP and multiply this by the concentration of the DCPIP.

For example, say it took 5.1cm^3 to decolourise the 0.1% ascorbic acid and 2.3cm^3 to decolourise the unknown orange juice.

(2.3/5.1) x0.1 = 0.045%

P.S I presume you did repeats so use your mean values....
I only have the one value of the 0.1% ascorbic acid, which it took 0.3ml of to decolourise the DCPIP.

It took 2.4ml of the non concentrate
3.2ml of the concentrate
2.3ml of the freshly squeezed

I need to know the vitamin content in each of the orange juices
in mg/ml ?? any ideas?
4. (Original post by k17)
I only have the one value of the 0.1% ascorbic acid, which it took 0.3ml of to decolourise the DCPIP.

It took 2.4ml of the non concentrate
3.2ml of the concentrate
2.3ml of the freshly squeezed

I need to know the vitamin content in each of the orange juices
in mg/ml ?? any ideas?
(Volume required in juice/volume required unknown) x0.1 as above. This gives you the %.

0.01% = 0.1mg/ml

So when you work out the % multiply your answer by 10....

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