copper solution that reacts with the reducing carbonyl group (C=O) in some
carbohydrates. All monosaccharides and the disaccharides maltose and lactose are
reducing. The concentration of reducing carbohydrate can be determined from
standard solutions of known glucose concentration.
Aim: To carry out an experiment to determine which drinks would be safest for a
diabetic person to drink without them having to worry about insulin levels.
Apparatus:
Benedict’s Solution
Test Tubes
Boiling Water Bath
Syringe
Drinks to test
Solutions of various sugar concentrations
Variables:
Temperature
Concentration
Ratio of Benedict’s solution to drinks
Method: First, 2ml of various drinks and sugar concentrations were put into test
tubes using a syringe. 1ml of Benedict’s was put into each test tube and mixed. All
the test tubes were then heated in a boiling water bath. The colours of the various
sugar concentrations were noted. The colours of the drinks were noted and compared
to the colours of the various sugar concentrations to find out the sugar concentrations
of the drinks.
Prediction/Hypothesis: My prediction for this experiment is that the mineral water
will have the lowest sugar concentration, and the diet lemonade will also have a very
low sugar concentration. I think that the cider and lemonade will have the highest
sugar concentrations. I think this simply because these drinks taste sweeter.
Results:
Colour
Sugar Concentration
Distilled Water
Blue
0.05
Green
0.1
Brown/Green
0.25
Brown
0.5
Orange/Red
1
Orange
5
Orange/Yellow
Diet Lemonade
Green
0.05
Lemonade
Orange
1
Cider
Orange/Yellow
5
Tonic Water
Orange/Yellow
5
Mineral Water
Brown/Green
0.1
Conclusion: The test was not very subjective, reducing its accuracy, although all the
test tubes were the same size and had the same clarity, so it was not inaccurate in
that respect. The ratio of drinks to Benedict’s was kept accurate
