Vitamin C titration with DCPIP: how to calculate content in fruit juices?

[xXAznGurlXx]

Hello there, I just needed help on this following problem, its a biology coursework i am doing and it states that,
The 1% vitamin C Solution contains 1mg of vitamin c in 1.0cm3. Calculate the mass of vitamin c that is required to decolourise 1cm3 of the DCPIP solution. then use this value to work out how much vitamin c each of the fruit juices contain, in mgcm-3


So far I have tested all my fruit juices using my burette and I have recorded the volumes that is needed to decolourise the DCPIP. my writeup is almost complete except for this problem that is asking me to do.

But one thing is i don't understand the question above is asking me

 

[Borek]

Do you know what chemical reaction takes place in your solution? This is a stoichiometry problem, you should start with the reaction equation.

 

[xXAznGurlXx]

Do you know what chemical reaction takes place in your solution? This is a stoichiometry problem, you should start with the reaction equation.

well I had a test tube and inside was 1cm3 of DCIPIP and my burette contained orange juice and had to slowly add drop by drop to the dcipip until it change colour.
I have to repeat the exact same procedure with grapefruit juice, blackcurrent juice, and a wide range of juices.

 

[Borek]

You are referring to the procedure. I am asking what chemicals do you mix and how do they react.

 

[xXAznGurlXx]

You are referring to the procedure. I am asking what chemicals do you mix and how do they react.

There were no chemicals involved, it's just those 2 solutions and when they react, it turned from blue to pinkish colour.
I mixed the orange juice with the DCPIP and then it changed colour.

 

[Borek]

There were no chemicals involved

Every single thing you deal with in your life is made of chemicals. You are made of chemicals - proteins, fat, water, carbohydrates, nucleic acids and mineral salts. Both your solutions were full of chemicals.

it's just those 2 solutions and when they react, it turned from blue to pinkish colour.
I mixed the orange juice with the DCPIP and then it changed colour.

DCPIP is one of chemicals involved. You have already named another one earlier.

 

[xXAznGurlXx]

So what do you suggest I should do into calculating the mass?

 

[Borek]

See my first post in the thread.