Effect of exposure - 1st experimental plan

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

2. What is the tentative explanation of your research question? (Hypothesis)
The lesser the orange juice is exposed to air, the better the retention of vitamin C.

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

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
- Time taken (for experiment)
- Temperature
- 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 plastic cups
- Aluminum foil
- Cling wrap
- Data logger with pH probe

7. What are the steps that you will take to carry out the investigation? (Procedure)
Step 1: Squeeze fresh orange juice, enough to fill half a cup.
Step 2: Take initial pH level of orange juice and record it down.
Step 3: Pour orange juice into a plastic cup and immediately cover the top of the cup with aluminum foil and cling wrap.
Step 4: Put the cup of orange juice in the fridge.
Step 5: Leave setup inside fridge for 3 hours and record the pH level of the juice every ½ hour with the help of the data logger and pH probe.
Step 6: Construct a table for the data and then plot a graph of pH level against time.
Step 7: Repeat step 1 and 2.
Step 8: Pour orange juice into cup and leave the top uncovered.
Step 9: Repeat steps 4-6.

8. How are data collected? (Data collection)
Data is collected with the data logger and pH probe. This device records the pH level of the orange juice at my chosen time and allows me to see the change in pH of the orange juice samples. 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 – both covered and not covered over time will show me how fast the vitamin C in each sample of orange juice is degrading. The orange juice sample that is covered will have less exposure to air while the sample that is not covered is constantly exposed to air throughout the entire duration of my experiment. This will then allow me to prove or disprove my hypothesis that the lesser the exposure to air, the better the retention of vitamin C in the orange juice.