Calorimetric Lab
Name : Soyun Soyun Park Teacher name: Mr. Parsons Date of submission: 26th November, 2013 Number of pages: pages: #12
Background Theory: The foods we eat provide energy, which is measured in kilo joules. A kilo joule is a unit of energy and also refers to the energy value of food and amount of energy our bodies burn. To determine the amount of energy in a particular food, we need to calculate the energy using the capacity of water multiplied by 4.2J (4.2J = 1calorie) and multiplied by the change in temperature. (Energy = capacity of water x 4.2 x change in temperature). temperature).
In the class we did a laboratory experiment to determine the amount of energy in different types of food. During our laboratory, we expected expected to find various levels of energy in different foods depending on their mass and components (e.g. protein, carbohydrate, fat, etc). The important element we were watching was the temperature of the water in the test tube. We knew the capacity of water would remain the same but the temperature change would reflect the different energy levels. The expected outcome was that foods that created greater temperature changes changes in the water would have higher energy levels. This relates to the real world when we are concerned about our kilo joule consumption. For activities that require more energy, energy, we need to t o eat foods with high energy or calorie content. Therefore, this lab is very practical in helping us to understand what types of food are best to eat to fulfill our required energy levels or output. Aim: To determine how the mass and food type affects the energy and power levels of food? Prediction: I think as mass increases, increases, the power and energy levels levels in food should also increase. I think this because knowing the formula of power and energy, mass plays a large role to get the results. Diagram:
Variables: -
Controlled variable: Capacity of water in the test tube, volume of water (5mL), room temperature, the length of needle.
-
Independent variable: Types Types of food (white peanuts, tango biscuit), mass of food(1g, 0.7g, etc), size of food (large peanut, small peanut, small piece of tango biscuit, etc)
-
Dependent variable: Time Time period from the food catching fire to it going out, temperature of the water (change in degrees Celsius from initial temperature to finishing temperature), energy(J)
Materials: - Test tube - Clamp stand - Bunsen burner - Gas - Matches - Bowl to keep the food in - Water - At least 2 different types of foods - Needle - Pen - Paper - Thermometer - Scales (to weigh the food) - Stop watch - Calculator - Safety glasses - Cork for needle - Beaker Method: Safety precautions: As partner or group, look at each other and check (hair, accessories, and clothes) - Check people with long hair have their hair tied up. - Remove jewelry, scarves, and anything loose that might get caught or in the way. - Remove bulky clothing items. - Whenever group members have to move, they should move intentionally, slowly, cautiously, carefully, carefully, and try not to distract others. - If carrying something easy to break like test tubes, group members should be moving slowly and focused while setting down. Method steps: 1. Ensure all safety precautions have been read and taken where appropriate. 2. Clear and prepare the experiment space. 3. Prepare Test tube, clamp stand, Bunsen burner, check the gas is working, matches, bowl to keep the food in, water, different types of foods, needle, pen, paper, thermometer, scales, stop watch, calculator and safety glasses. 4. Fill the test tube with water up to 5mL line. (Note: Other groups using other foods used 10mL of water -see results in appendix). Measure the temperature of the water using thermometer. Record temperature in degrees Celsius. 5. Insert test tube with water inside firmly into the clamp stand. 6. Turn the gas of the Bunsen burner on and light a flame with the match. 7. Select an item of food and weigh in on the scales. Record the mass in grams. 8. Pierce the food with a needle so the food is secured on the end of the needle. 9. Select member of the group to be time keeper and time recorder. (Have stop watch to time) 10. Take the needle and hold the end with food on it over the flame of the Bunsen burner until it catches the flame. Start the stop watch now. 11. Move the burning food and hold under the test tube containing water until t he flame goes out and smokes. Stop the stop watch now. Record the time taken. Measure the temperature change of the water and record. 12. Measure and record the weight of the burned food. 13. Throw away burned food and repeat experiment above 3 more times to ensure the results are consistent. 14. Make sure to turn off all the gas and put away all materials and equipment safely. 15. Done.
To ensure we got accurate measurement and results, we used the same equipment including thermometer, scales, and stopwatch throughout the entire experiment. We zeroed the scales before using them each time. (The scales were very sensitive which made it hard to get consistent measurements due to wind affecting the scale reading.- To minimize the discrepancy this caused, I ensured windows and doors were closed where possible.) Method for graph: 1. Formula for the energy: Q=mC△t. Capacity of water multiplied by 4.2J multiplied by the change in temperature. (Q= heat, m=mass, C = specific heat, △t = temperature changes.) The reason why multiplying 4.2J in the formula is because 1calorie is equal to 4.2J. 2. Formula for the power:
Joules Second
and unit for the power is Watt(W).
Results/ Data collection: Table 1
Groups
Average of mass(g)
Average of energy(J)
White Peanut g1
0.5
609
White Peanut g2
0.2
1295
White Peanut g3
0.5
508.2
Brown Peanut g1
0.2
2366
Krupuk g1
0.7
215
Lays chips g1
0.6
791
Lays chips g2
0.2
217
Table 2 class.> Groups Average of mass(g) Average of power(W) White Peanut g1
0.5
14.8
White Peanut g2
0.2
55
White Peanut g3
0.5
15.5
Brown Peanut g1
0.2
44.7
Krupuk g1
0.7
10.6
Lays chips g1
0.6
11.5
Lays chips g2
0.2
18.5
Table 3 Trials
Mass(g)
Energy(J)
Power(W)
White Peanut T1
0.3
420
8
White Peanut T2
0.4
609
9.2
White Peanut T3
0.7
1281
27.3
White Peanut T4
0.3
378
6.1
White Peanut T5
0.7
357
6.5
Graph This graph shows the results for the energy and mass of white peanuts which is the food type our group experimented on.
This graph shows the relationships between the average energy and average mass of all the f ood types experimented experimented on by the entire class.
This graph shows average mass and energy of each food type experimented on in t his entire class.
This graph shows the results of the energy and mass of the White peanuts our group experimented experimented on.
White peanuts energy and mass 1281
1400 1200
y g r 1000 e n e 800 d n a 600 s s a 400 M
200
609 420
378
357
Mass(g) Energy(J)
0.3
0.4
0.7
0.3
0.7
White
White
White
White
White
0 Peanut T1 Peanut T2 Peanut T3 Peanut T4 Peanut T5 White Peanuts Trials
This graph shows the relationship of the power and mass of the White peanuts our group experimented on.
This graph shows the results for the power and mass of White peanuts our group experimented experimented on.
This graph shows the relationship of the power and mass of all the food types experimented on in entire class.
This graph shows the results for the average power and mass of all the food types experimented on in entire class.
Data Analysis: The energy and power depend on mass, the different types of food and components. In our group, we experimented experimented on white peanuts for 5 trials.
Trial1 and Trial 4 white peanuts had the same mass of 0.3g. Trial Trial 1 had energy of 420J and power of 8W. Trial 4 had energy of 378J and power of 6.1W. We expected these results to show similar levels of energy and power due to using one food type of same mass. Trial 2 had mass of 0.4g and energy of 609J and power of 9.2W. As expected, the energy and power levels were higher and Trial 2, due to the larger mass of the peanut. Trial Trial 3 and 5, both had 0.7g of mass but showed very different different levels of energy and power; 1281J and 27.3W, and 357J and 6.5W respectively. These results were not consistent with the expected pattern pattern but this is due to the timing issue we had during trial 3 which would have affected these results (see t he evaluation). However in Lays chips g2 and brown peanuts g1, they had same mass but different energy and power. Both brown peanuts g1 and lays chips g2 had same mass of 0.2g. Brown peanuts g1 had energy of 2366J and had power of 44.7W. The lays chips had the energy of 217J and had power of 14.8W. We say that the energy and power are depending on mass but we can also see that they depend on which food types and their components. The brown peanuts have different components to the lays chips. That’ That’s why it has higher power and energy. In the graph, we can see that even when the mass is bigger, it does not necessarily mean the energy and power will be higher. Energy and power are also affected by the type of food. food. Conclusion: There is no clear pattern for the relationship between mass, energy, and power of the white peanuts. However this could be due to the irregularities of the experiment. The only pattern that can be seen is the relationship between mass, power and energy within particular food types tends to be consistent.
The results from the experiments of our group showed unclear results in terms of the relationship between mass, mass, power and and energy in white peanuts. You can see in Table Table 3 that a larger mass mass did not necessarily result in higher energy or power levels. In Tables 1 and 2, you can also see varied results from the white peanuts experimented on by different groups. There is no real consistency or pattern shown in the results across all three of the groups t hat experimented on White peanuts. The results from our group experiment as well as the results from the other class groups’ experiments groups’ experiments were not in line with what I had predicted. I predicted that as mass increased, the power and energy levels in food would also increase. However the results did not reflect this prediction as many groups found trials with lesser mass actually had higher energy and power levels, not lower as we were expecting. Theoretically, a larger mass should increase power and energy levels in the food if we were to use the formulas. But I think maybe we require more ti me to experiment further and explore this prediction. As detailed in the Background Theory Theory of this report, I expected that different foods with different components would have different levels of power and energy. This can be clearly seen in Table 1 which shows the results of Brown peanuts and lays chips. You can see both food types consisted of an average 0.2g, but have very different power and energy levels. Brown Peanuts on average had over 10 times the energy levels than the same mass of lays chips (2366J vs. 217J respectively). Brown peanuts on average also had almost two and a half times greater power levels than lays chips (44.7W vs. 18.5W respectively.)
Evaluation: If we had more time to repeat the experiments a greater number of times, we would get more consistence results. We We could also improve this experiment by testing t esting with an even greater variation of food. We We could compare various types of foods like protein vs. carbohydrates vs. fats etc.
The limitations for this lab included the Bunsen burner’s strength were hard were hard to control and keep consistent because of wind and gas flow. The distance distance between the burning food and the t he bottom of the test tube was difficult to keep consistent, next time we could set a particular height at which the food had to be held. Again, to get more accurate measurements measurements of food mass, next time we would aim to weigh the food in an environment void of wind. We got a strange result on our third White Peanut Trial, showing a really high finishing temperature. However during trial 3, the peanut did not catch fire properly the first time so we had to light it again with the Bunsen burner, which may have been a strong factor in why the temperature change of the water was so dramatic. To perform this experiment better next time, I would suggest to experiment with a wider variation of food types, to repeat the experiment a greater number number of times to get more consistent results, to record measurements measurements and materials, materials, size and types more specifically (e.g. needle length) to remove or limit any external factors that may affect the results (e.g. wind). Through this experiment, I learned a lot and had a lot of fun.
Appendix
I did not make table or graph for the food t ypes I did not highlight. It is because I did not have enough trials and accurate results. Also they are not valid. The chart above shows all of the grade 8’ 8’s experiment for calorimetric lab.
