# Homework Help: Glucose anaylsis of sports drinks

1. Oct 29, 2006

### Tiptronic

Just realised wrong forum...sorry.

I need some urgent help with this please!!

This is referring to my glucose analysis coursework, using Quantitative Benedicts solution (with potassium thiocyanate) and titrations to find out how much glucose is present in Lucozade and Powerade.

I was told to use the fact that my Quantitative Benedicts Solution contained 18g of CuSO4.5H20, copper sulphate-5-water, in order to justify the percentage concentration of the Lucozade drink I used during the titration.

So, this is what i did, but i think it is most probably wrong.

I found the Molar mass of CuSO4.5H20 = 279 g mol-1

number of moles = 18/249 = 0.072 mol

In order to callibrate the Quantitative Benedicts Solution, I first used 0.5g glucose disolved in 100cm3 water and did a titration with that.

So, the molar mass for glucose is 180 g mol-1

I used 0.5g here, so:

number of moles = 0.5/180 = 0.0028 mol

I now have two values, 0.072 and 0.0028 mol.

Through wishful thinking i did this:

0.072/0.0028 = 25.71

25.71 x 0.5 = 12.9

So I then somehow would say that justifies using 12.9% concentrations for my glucose drinks that im testing (Lucozade and Powerade)?

Help please?

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