Friday 24 June 2011

Final experiment - data

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


 

Orange juice samples in room temperature. (31 degrees Celsius)

Orange juice samples in the fridge. (8 degrees Celsius)


10. How to organize and present the data collected? (Results)
1st experiment
Initial pH level of orange juice samples: 3.48
Elapsed Time (hours)
pH Level of Covered Orange Juice Sample in Fridge (8°C)
pH Level of Exposed Orange Juice Sample in Fridge (8°C)
pH Level of Covered Orange Juice Sample in Room Temperature (31°C)
pH Level of Exposed Orange Juice Sample in Room Temperature (31°C)
0
3.48
3.48
3.48
3.48
¼
3.48
3.49
3.48
3.49
½
3.49
3.52
3.50
3.54
¾
3.51
3.54
3.52
3.58
1
3.53
3.56
3.55
3.61
1¼ 
3.56
3.60
3.56
3.65
3.57
3.65
3.58
3.69
3.58
3.68
3.60
3.72
2
3.60
3.71
3.63
3.77
3.61
3.73
3.64
3.79
3.64
3.77
3.66
3.83
3.66
3.81
3.70
3.86
3
3.67
3.82
3.74
3.89



Initial pH level
pH level at the end of 3h
Change in pH level
Percentage of change in pH (%)
Sample of covered orange juice in fridge
3.48
3.67
+0.19
+5.46
Sample of exposed orange juice in fridge
3.48
3.82
+0.34
+9.77
Sample of covered orange juice in room temperature
3.48
3.74
+0.26
+7.47
Sample of exposed orange juice in room temperature
3.48
3.89
+0.41
+11.8

2nd experiment
Initial pH level of orange juice samples: 3.32
Elapsed Time (hours)
pH Level of Covered Orange Juice Sample in Fridge (8°C)
pH Level of Exposed Orange Juice Sample in Fridge (8°C)
pH Level of Covered Orange Juice Sample in Room Temperature (31°C)
pH Level of Exposed Orange Juice Sample in Room Temperature (31°C)
0
3.32
3.32
3.32
3.32
¼
3.32
3.33
3.33
3.33
½
3.34
3.35
3.35
3.36
¾
3.36
3.38
3.36
3.41
1
3.37
3.40
3.38
3.44
1¼ 
3.40
3.44
3.41
3.48
3.42
3.46
3.44
3.53
3.43
3.50
3.46
3.57
2
3.45
3.55
3.47
3.62
3.46
3.59
3.50
3.65
3.47
3.63
3.54
3.70
3.49
3.67
3.58
3.74
3
3.52
3.69
3.61
3.80



Initial pH level
pH level at the end of 3h
Change in pH level
Percentage of change in pH (%)
Sample of covered orange juice in fridge
3.32
3.52
+0.20
+6.02
Sample of exposed orange juice in fridge
3.32
3.69
+0.37
+11.1
Sample of covered orange juice in room temperature
3.32
3.61
+0.29
+8.73
Sample of exposed orange juice in room temperature
3.32
3.80
+0.48
+14.5

11. What do the data mean? (Data Analysis)
From both experiments, we can see that the pH of all four samples of orange juice increase over time. However, the pH of the two exposed samples of orange juice increase at a faster rate than the two covered samples of orange juice. There is also a greater change (increase) in pH levels of the exposed samples of orange juice at the end of 3 hours compared to the covered samples. In the first experiment, the exposed sample of orange juice in room temperature experienced 4.33% more increase in pH than the covered sample in room temperature. Likewise, the exposed sample in the fridge had a 4.31% more increase in pH than the covered sample in the fridge.

The pH level was also affected by the difference in temperature. The orange juice samples placed in the fridge were kept at 8°C while the samples outside in room temperature were kept at 31°C for 3 hours concurrently. From both experiments, we can see that 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 second experiment, the covered sample of orange juice in room temperature had a 2.71% more increase in pH than the covered sample in the fridge. Likewise, the exposed sample in room temperature increased 3.4% more in pH compared to the exposed orange juice sample 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 orange juice when the juice is exposed to air and when it is stored in warmer temperatures. Also, since there were no other affecting factors to the change in pH level of the orange juice aside from exposure to air and storage temperature, and the experiment was repeated to 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 exposure to air affects the degradation of vitamin C in orange juice. The more the exposure to air, the faster the rate of degradation of vitamin C in orange juice. This also means that the lesser the orange juice is exposed to air, the better the retention of vitamin C. I can also 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 I can then prove that it is best to store orange juice without exposure to surrounding air and in cold temperatures (to minimize the degradation of vitamin C, shown by the change in pH). This then proves my hypothesis right.


Final experiment - 1st experimental plan

1. What do you want to find out? (Aim/Purpose/Research question)
The best way to store orange juice so as to minimize the degradation of vitamin C.

2. What is the tentative explanation of your research question? (Hypothesis)
It is best to store orange juice without exposure to the surrounding air and in cold temperatures to minimize the degradation 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 and temperature of which the orange juice is 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
- Duration of experiment
- 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
- 4 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 2 whole cups.
Step 2: Take initial pH level of orange juice and record it down.
Step 3: Pour orange juice equally into 4 plastic cups.
Step 4: Immediately cover the top of 2 cups with aluminum foil and cling wrap, and leave the other 2 cups uncovered.
Step 5: Put 1 covered cup and 1 exposed cup of orange juice in the fridge, and 1 covered cup and 1 exposed cup outside in room temperature.
Step 6: Leave setups at their respective places for 3 hours and record the pH level of the samples 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.

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 samples – both covered and not covered, in cooler or warmer temperatures over time will show me how fast the vitamin C in each sample of orange juice is degrading. The orange juice samples that are covered will have less exposure to air while the samples that are not covered are constantly exposed to air, and the juice samples in the fridge would be experiencing lower temperature while the samples outside in room temperature would be in higher temperature throughout the entire duration of my experiment. This will then allow me to prove or disprove my hypothesis that it is best to store orange juice without exposure to the surrounding air and in cold temperatures to minimize the degradation of the vitamin C content.

Wednesday 8 June 2011

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)
1st 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
 
3.48
3.54
3.49
3.58
3.51
3.60
2
3.54
3.62
3.56
3.63
3.57
3.67
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

2nd 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
 
3.42
3.48
3.45
3.50
3.46
3.53
2
3.48
3.55
3.51
3.60
3.52
3.63
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.