1. Estimating glucose concentration in solution
Paul Beaumont

2. Developed by:
Marjorie Smith, Dollar
Funding from
SAPS
AstraZeneca

3. Aims
To investigate the effect of increasing glucose concentration on the rate of reaction.
To estimate the concentrations of 2 glucose solutions of unknown concentration.

4. ∝ Glucose is a reducing sugar:
MnO4- is purple, Mn2+ colourless – time taken for complete colour removal [Glu] ∝

5. Materials (per group) 2 small beakers White tile Stopwatch Graph paper
3 syringes (5 cm3)
Indelible pen

6. Materials (per group) 2 small beakers White tile Stopwatch Graph paper
3 syringes (5 cm3)
Indelible pen
Distilled water (ca. 20 cm3)
Sulfuric acid (ca. 50 cm3)
Potassium permanganate
(ca. 20 cm3)
Glucose solutions
(7 standards and 2 unknowns)
9 boiling tubes
Rack

7. Procedure 20 cm3 of distilled water in beaker
2% glucose solution (10 cm3)
Sulfuric acid (10 cm3)
Potassium manganate (2 cm3)

8. Procedure 20 cm3 of distilled water in beaker
2% glucose solution (10 cm3)
Sulfuric acid (10 cm3)
Potassium manganate (2 cm3)
Record the time taken for colour to completely disappear –may > min.
Repeat for remaining solutions.
Estimate glucose in unknowns.

9. Results