Date: 21st September 2011
Title: ESTIMATING GLUCOSE CONCENTRATION IN SOLUTION
How do the different glucose concentration in unknown solution which labelled A,B,and C are determined from the time taken for the loss of colour from a standardised solution of permanganate based on the different glucose concentration in known solution which are 5%, 10%, 15%, 20%, 25%, and 30% under the constant factors of volume of sulphuric acid, volume of potassium permanganate, and volume of glucose? Variables:
INDEPENDENT VARIABLE| Different concentration of glucose in solution| %| 5%, 10%, 15%, 20%, 25%, 30%, and A, B, C| DEPENDENT VARIABLE| Time taken for the loss of colour from a standardised solution of permanganate| s| Will be determined in the experiment|
No.| CONTROLLED VARIABLES| Units| Possible effect(s) on result| 1| Volume of sulphuric acid| cm3| Affect the no. of hydrogen ions (H+) produced for the reaction| 2| Volume of potassium permanganate| cm3| Affect the time taken for the loss of the colour| 3| Volume of glucose solution| cm3| The time taken will not be uniformly in sequenced order based on the concentration|
Higher concentration of glucose in solution will shorten the time taken for the loss of colour from a standardised solution of permanganate. Glucose with higher concentration will transfer higher number of electron, thus fasten the reaction on producing manganese ions (Mn2+) and water (H2O). Hence, the colour will changes from pink to colourless in shorter time.
Method For Controlling Variables:
No.| CONTROLLED VARIABLES| Method to control|
1| Volume of sulphuric acid| Fix the volume of sulphuric acid at 5cm3 for every test | 2| Volume of potassium permanganate| Fix the volume of potassium permanganate at 2cm3 for every test| 3| Volume of glucose solution| Fix the volume of each glucose solution at 10cm3 for every test|
Method For Collecting Data:
1. 3 beakers and 3 syringes were labelled:
S – for Sulphuric Acid
PP – for Potassium Permanganate
G – for Glucose
2. 25cm3 of sulphuric acid and potassium permanganate were added into the beakers – this will be the stock to use throughout the experiment. Glucose solution which tested first was noted.
3. Correct syringe was used to place 10cm3 of the first glucose solution into the boiling tube.
4. 5cm3 of sulphuric acid was added.
5. 2cm3 of potassium permanganate was added. The clock was started immediately.
6. The solution was stirred using glass rod and the time taken was stopped as soon as the pink colour changed into colourless.
7. The time taken and the glucose solution used were recorded.
8. The syringe used for the glucose solution was rinsed.
9. Step 3 – 8 were repeated using the other glucose solution of known concentration.
10. Step 3 – 8 were repeated using the solution of unknown solution (A,B, or C)
11. The results were recorded and presented in a Standart Curve.
DATA COLLECTION AND PROCESSING
ASPECT 1 : DATA COLLECTION
Table 1 : Recording Quantitative Raw Data of Known Solution
Glucose concentration in solution| Time taken for the loss of colour of potassium permanganate,t (s) ±0.01s| | Group 1| Group 2| Group 3| Group 4| Group 5| Group 6| 5%| 241| 348| 315| 345| 265| 363|
10%| 125| 220| 71| 147| 141| 92|
15%| 47| 65| 50| 90| 88| 75|
20%| 40| 125| 37| 83| 42| 53|
25%| 37| 85| 35| 35| 39| 45|
30%| 27| 42| 32| 30| 29| 39|
*My data group was in Group 4
Table 2: Recording Quantitative Raw Data of Unknown Solution Glucose concentration in solution| Time taken for the loss of colour of potassium permanganate,t (s) ±0.01s| | Group 1| Group 2| Group 3| Group 4| Group 5| Group 6| Boiling tube A| 118 | 240 | 139 | 108 | 121 |...