Effect of temperature - data

9. How to show that the experimentation was carried out as reported? (Evidence) Use of photograph, audio or recording.

Pouring freshly squeezed orange juice into a boiling tube.

Orange juice sample in fridge. (8 degrees Celcius)

Orange juice sample in room temperature. (30 degrees Celsius)

Taking the pH level of an orange juice sample.

10. How to organize and present the data collected? (Results)

1^st experiment

Initial pH level of orange juice samples: 3.40

Elapsed Time (hours)	pH Level of Orange Juice Sample in Fridge (8°C)	pH Level of Orange Juice Sample in Room Temperature (30°C)
0	3.40	3.40
¼	3.41	3.42
½	3.42	3.45
¾	3.45	3.49
1	3.46	3.51
1¼	3.48	3.54
1½	3.49	3.58
1¾	3.51	3.60
2	3.54	3.62
2¼	3.56	3.63
2½	3.57	3.67
2¾	3.58	3.69
3	3.60	3.73

	Initial pH level	pH level at the end of 3h	Change in pH level	Percentage of change in pH (%)
Sample of orange juice in fridge	3.40	3.60	+0.20	+5.88
Sample of orange juice in room temperature	3.40	3.73	+0.33	+9.71

2^nd experiment

Initial pH level of orange juice samples: 3.34

Elapsed Time (hours)	pH Level of Orange Juice Sample in Fridge (8°C)	pH Level of Orange Juice Sample in Room Temperature (30°C)
0	3.34	3.34
¼	3.36	3.36
½	3.37	3.39
¾	3.38	3.41
1	3.40	3.44
1¼	3.42	3.48
1½	3.45	3.50
1¾	3.46	3.53
2	3.48	3.55
2¼	3.51	3.60
2½	3.52	3.63
2¾	3.54	3.65
3	3.57	3.69

	Initial pH level	pH level at the end of 3h	Change in pH level	Percentage of change in pH (%)
Sample of orange juice in fridge	3.34	3.57	+0.23	+6.89
Sample of orange juice in room temperature	3.34	3.69	+0.35	+10.5

11. What do data mean? (Data Analysis)

The orange juice sample placed in the fridge was kept in 8°C while the sample outside in room temperature was kept at 30°C for 3 hours concurrently. From both experiments, we can see that the pH of both samples of orange juice increase over time. However, the pH level of the orange juice samples out in room temperature increase at a faster rate than the orange juice samples in the fridge. There is also a greater change (increase) in pH levels of the samples in room temperature at the end of 3 hours compared to the samples in the fridge. In the first experiment, the sample in room temperature experienced 3.83% more increase in pH compared to the sample in the fridge. In the second experiment, the orange juice in room temperature had 3.61% more increase in pH than the orange juice in the fridge.

This increase in pH level shows the rate at which the vitamin C content in the orange juice is degrading. This shows that vitamin C degrades faster in the orange juice when the juice is stored in warmer conditions. Also, since there were no other affecting factors to the change in pH level of the orange juice aside from difference in storage temperature, and the experiment was repeated and achieved similar results, it is safe to say that it is fairly accurate.

12. What can you deduce from the discussion of your data analysis? (Conclusion)

With this set of data, I can deduce that different storage temperatures affect the degradation of vitamin C in orange juice. The higher the temperature the orange juice is stored in, the faster the rate of degradation of the vitamin C content in the juice. This also means that the lower the temperature, the better the retention of vitamin C in orange juice, therefore proving my hypothesis right.

Effect of temperature - 3rd experimental plan

I changed the experimental procedure once more because I discovered that some problems would occur in the process of carrying out the old experimental plan.

New procedure:
Step 1: Squeeze fresh orange juice.
Step 2: Take initial pH of orange juice and record it down.
Step 3: Pour orange juice equally into 2 boiling tubes, each 1/3 a boiling tube.
Step 4: Immediately cover the top of both boiling tubes with aluminum foil and cling wrap.
Step 5: Put one setup in the fridge and one in room temperature.
Step 6: Leave setups in respective locations for 3 hours and record the pH level of the juice every 15 minutes with the help of the data logger and pH probe.
Step 7: Construct a table for each set of data and then plot separate graphs of pH level against time.
Step 8: Repeat entire experiment once more.

I decided not to have the sample of orange juice in the freezer as it would not be possible to measure the pH level of that sample. After a while, the juice in the freezer would freeze and to be able to take the pH level of a sample, it has to be in liquid form. Waiting for the sample to melt and take the pH level would mess up the timings and make the readings and results inaccurate. Therefore, it is better not to test a sample in the freezer. So, now there will only be one setup left in the fridge and one out in room temperature.

Effect of temperature - 2nd experimental plan

I changed the experimental procedure as the old procedure would have resulted in confusing results. In changing the procedure, I also changed the materials and apparatus needed for the experiment.

New materials:
- Freshly squeezed orange juice
- 3 boiling tubes
- Aluminum foil
- Cling wrap
- Data logger with pH probe
- Test tube rack

New procedure:
Step 1: Squeeze fresh orange juice.
Step 2: Take initial pH of orange juice and record it down.
Step 3: Pour orange juice equally into 3 boiling tubes, each 1/3 a boiling tube.
Step 4: Immediately cover the top of all the boiling tubes with aluminum foil and cling wrap.
Step 5: Put one setup in the fridge, one in the freezer and one in room temperature. (Measure their exact temperatures)
Step 6: Leave setups in respective locations for 3 hours and record the pH level of the juice every 15 minutes with the help of the data logger and pH probe.
Step 7: Construct a table for each set of data and then plot separate graphs of pH level against time.
Step 8: Repeat entire experiment once more.

Firstly, I realised that with the old experiment procedure, both setups (one left in the fridge, one held over a flame) would take different amounts of time to achieve the desired results. The temperature change would be faster in the orange juice sample held over the flame as it would take less time for it to heat up and for the results to be logged by the data logger. However, the sample left in the fridge would take a longer time for the juice to cool down and its temperature to reach a standstill, for us to observe the results. Due to this, the results may be affected by how long the change in pH of the orange juice samples are being monitored. The longer the orange juice is being observed, the more of the vitamin C content degrades.

With this new experiment procedure, all the orange juice samples are kept at different constant temperatures, being monitored for the same amount of time. This will make sure that difference in time does not affect the results collected, and still allow us to see how difference in temperature affects the retention of vitamin C in orange juice.

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.