[DanUK]

Hi, im new here, so sorry if i have put it in the wrong section.

Im doing an experiment at school for my coursework, and i was wondering if these are ym results..

its takes ... 11.1cm3 of my 0.025mol dm3 fructose solution to turn my benedicts solution white, when titrating.

and when i used my 10% diluted apple juice solution, it took 5.7cm3 to turn 25cm3 of benedicts solution white.

(i added 10grams of anhydrous sodium carbonate to the 25cm3 of benedicts solution, then boiled it and titrated while boiling)

can any one help me work out the amount/ concentration of fructose in my apple juice.

Thankyou
              DanUK.

[Borek]

my 0.025mol dm3 fructose solution

What volume of that solution?

How many moles of fructose in the sample?

How many moles titrated by 1 mL of Benedict's reagent?

How many moles of ructose in titrated sample?

[DanUK]

oops sorry i meant to say it was 11.1cm3 of my 0.025mol dm3 fructose solution to turn 25cm3 of my quantitative benedicts solution white.

[Borek]

My questions remain correct.

[DanUK]

hi i have these results.

it takes 11.1cm3 of 0.025mol dm3 fructose solution to turn my quantitative benedicts solution white.

It takes 5.7cm3 of my 10% apple juice solution to turn benedicts solution white.

These are my workings, can you tell me whether they are correct. thankyou.

using n=c*v , (number of moles = concentrations x volume in dm3)

 (0.025*11.1)/1000 = 0.0002775 moles of fructose used to turn the benedctis white.
             
therefore from this, the same ammount of fructose will be needed to turn the quantitative  benedicts solution white when using my 10% apple juice solution.

so 5.7cm3 of 10% apple juice solution will have 0.0002775 moles of fructose in it.

to see how much is in 1cm3 i divide the 0.0002775 by 5.7 which equals.. 0.00004868421 mols of frutose in 1cm3

i then times by 1000 to give me the ammout of fructose in 1dm3 = 0.00004868421*1000= 0.04868421 mol dm3 of fructose in my 10% apple juice solution.

i then times by 10 to see how concentrated my 100% apple juice solution would be so 0.04868421*10= 0.4868421 mols dm3 in my 100% apple juice solution.


is my method right? please help, need some reassurance. Thanks DanUK.

[Borek]

I have not checked the numbers, but the approach seems OK.

[DanUK]

lovely thanks