Type of Fruit Juice / Control
| Amount of liquid needed to decolourise DCPIP (cm³)
| Concentration of Vitamin C (mg/cm³)
3.5/volume of fruit juice = ____mg/cm³ of Vitamin C in the fruit juice.
The experiment was reliable as we repeated; the experiment and we cross referenced it with other groups. Our validity is ensured by the use of a control variable as well as an independent and dependant variables. Our accuracy should be spot on for the burettes and other precision equipment is calibrated and checked regularly for damage. Any systematic errors such as all our results being consistently inaccurate by the same amount, that occurred will be a result of the equipment being faulty opposed to it being us as we followed the instructions to the letter, this also eliminates the occurrence of random errors such as a single result being grossly inaccurate, this being said any discrepancies that may have occurred will be a direct result of poor cleaning of the beakers and such like, but I tried to stop this by cleaning all our beakers after each experiment.
The dependant variable is the amount of juice used and the independent variable is the type of juice used in the experiment. METHOD:
SAFETY: Take care with fragile glassware such as burettes.
1.) Make up a 1% solution of vitamin C with 1 g of vitamin C in 100 cm3; this is 10 mg cm–3. 2.) Make up a 1% solution of DCPIP.
3.) Pipette 2 cm3 of vitamin C solution into a test tube.
4.) Using a graduated pipette or a burette, add 1% DCPIP drop by drop to the vitamin C solution. Shake the tube gently after adding each drop. Add DCPIP solution until the blue colour of the final drop does not disappear. 5.) Record the exact amount of DCPIP solution that was added. 6.) Repeat the procedure...
Please join StudyMode to read the full document