Wednesday 1 June 2011

Effect of temperature - 1st experimental plan

1. What do you want to find out? (Aim/Purpose/Research question)
The effect of temperature on the retention of vitamin C in orange juice.

2. What is the tentative explanation of your research question? (Hypothesis)
The lower the temperature, the better the retention of vitamin C in orange juice.

3. In an investigation, there is only one variable to be changed. Which variable will you change in this investigation? (Independent variable)
Temperature of which the orange juice is being kept at.

4. All the other variables must be kept constant. What are a few important variables that will affect the results greatly? (Constant variables)
- Type of orange juice
- Amount of orange juice
- Amount of exposure
- Material of container
- Size of container

5. What results will you measure? (Dependant variable)
The pH level of the orange juice.

6. What are the materials and apparatus that you will need to carry out the investigation? (Materials and apparatus)
- Freshly squeezed orange juice
- 2 boiling tubes
- Aluminum foil
- Data logger with pH probe
- Test tube rack
- Test tube holder
- Bunsen burner

7. What are the steps that you will take to carry out the investigation? (Procedure)
Step 1: Squeeze fresh orange juice, enough to fill ¼ of a boiling tube
Step 2: Pour orange juice into boiling tube and immediately cover the top of the boiling tube with aluminum foil.
Step 3: Poke pH probe through aluminum foil and put boiling tube in the test tube rack with the data logger into the fridge.
Step 4: Leave setup inside fridge to record the change in temperature and change in pH until the temperature reaches a standstill.
Step 5: Remove the setup from the fridge and save the data logged on the data logger.
Step 6: Construct a table for the data and plot a graph of pH level against temperature.
Step 7: Repeat step 1 and 2.
Step 8: Poke pH probe through aluminum foil and hold boiling tube over a flame.
Step 9: Leave setup over flame to record the change in temperature and change in pH until the temperature reaches a standstill.
Step 10: Remove the setup from over the flame and save the data logged on the data logger.
Step 11: Repeat step 6.
Step 12: Repeat entire experiment once more.

8. How are data collected? (Data collection)
Data is collected with the data logger and pH probe. This device can record the pH level and temperature of the orange juice throughout the duration of the experiment and this allows me to see the change in pH of the orange juice samples in relation to the change in temperature. By observing the pH change in the juice, I am then able to determine which condition best allows the retention of vitamin C, as vitamin C is ascorbic acid. The increase in pH level of the juice in different temperatures will show me how fast the vitamin C in each sample of orange juice is degrading. The orange juice sample in the fridge would be experiencing decreasing temperature while the sample over the flame would be under increasing throughout the entire duration of my experiment. This will then allow me to prove or disprove my hypothesis that the lower the temperature of the orange juice, the better the retention of vitamin C.

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