The most common fats are lard and ripping. They are composed of three large molecules in which three fatty acids are joined to glycerol to form a triglyceride. Fatty foods are used for energy.
Most of a fatty acid molecule is made of carbon and hydrogen. They are burnt and then give off energy. Over seventy different fatty acids have been isolated from nature; most of these contain fifteen to eighteen carbon atoms. In the diagram drawn below, the dots (…) represent more carbon atoms. If these middle carbon atoms have less than two hydrogen’s each then they are said to be ‘unsaturated’. This means that they are not saturated with hydrogen.
H H H H H O
H C. . . C C C C C
H H H H H O
Formulas:
The formulas that I am gong to use in this experiment are as follows:
To calculate energy in J.
Energy from food = Weight of water (g) × temperature rise (0’C) × 4.2
To calculate energy in J/g.
Energy in food = Energy in J ÷ weight in g.
To calculate the weight of water.
1ml = 1g
Prediction:
I predict that pumpkin seed will heat up the water in the boiling tube quicker than the other foods. I think that the dried pea will take the slowest to heat up the boiling tube and will release the least amount of energy compared to the other foods being used.
Equipment List:
The apparatus that I am going to use to carry out this experiment are as follows:
- Retort stand.
- 6 boiling tubes.
- Syringe.
- Thermometer.
- Probe.
- 2 Heat proof mats.
- Goggles.
- 6 different types of food
-Sunflower seeds.
-Pumpkin seeds.
-Pasta.
-Crisp bread.
-Dried peas.
Safety Aspects:
The safety aspects that I must consider to use to ensure that my experiment is carried out in a safe way are as follows:
- Tie long hair back so that it is not in the way and also so that it does not have the risk pf getting burnt n the Bunsen burner or when holding the burning food in the probe.
- Secure any loose such as ties by wearing lab coats over the uniform.
- Wear safety goggles at all times during the experiment.
- Do not poke anyone with the probe and carry it in a safe way when setting up and carrying out the experiment.
- Have a heatproof mat to put the hot burnt food on once the food has been used in the experiment.
- Do not put the retort stand too close to the edge so that it des not fall of and hurt somebody.
Fair Test:
The experiment must be carried out in a fair way. So to make it a fair test, I am going to repeat the experiment three times over. The same amount of water must be used each time. If this was to change then all of the results would have to change and this would not make the experiment a fair test. The must be changed from the test tube every time it is being used so it must not be same water used each time. The food must be held from the boiling tube at the same length each time. If one food is held closer to the boiling tube then this could alter the whole set of results. The same thermometer and the same types of boiling tubes should be used each time. The test tube must also be changed every time a new food is being burned. The test tube and water must not be hot when each food is being heated up. This is because, the water has to start at the same temperature.
Variables:
The variables of the experiment are as follows:
Control variable:
The type of boiling tube used in the experiment. They must all be the same thickness and must originate from the same company. The same amount of water must be used. The same thermometer.
Dependant Variable:
The energy changing in every gram.
Independent Variable:
The fat in the six different types of food.
Method:
This is the method that I am going to use to carry out my experiment:
- First of all, you must weigh all six types of food.
- Set up all the equipment and make sure the safety mats are out so that the bench does not get ruined.
- Syringe 20ml of water into the test tube that has been put in the retort stand.
- Light the food with the flame from the Bunsen burner.
- Note initial temperature. The heat from the food will go to the air, into the glass and all of the food will not burn.
- Put the lighted food underneath the boiling tube with the water in side of it and allow the boiling tube to heat up.
- Note the final temperature.
Diagram:
Here is a diagram to show the way in which the experiment was set up and the way in which it was carried out.
Results:
Here is a table of results to show my 1st set of results:
Here is a table to show Rebecca’s set of results:
Conclusion:
Once carrying out the experiment I was able to find out that pumpkin seeds had the most energy and dried peas had the least amount of energy in them out of all six types of food.
I have collected my results and put them on a line graph. The results that I got did not have a good line of best fit. It was very hard to fit the line of best fit on the average graph as well. My results on the graph are spaced out so much and are not in correlation with one another. This just shows that the experiment was carried out in a wrong way and may not have been done in a fair test or the method may not have been carried out.
Even though I do not have a line of best fit on the graphs, I still can see a couple of anomalies. The plain crisp had 37grams of fat in 100grams. But the results were not even close to each other. My results are wrong and show that the plain crisp has the most amount of energy hen in actual fact, the pumpkin seed has the most amount of energy. But the rest of the results are close to each other but Rebecca’s crisp bread result is not near to my crisp bread results. The graph also shows that the Rebecca’s set of crisp brad results were two high.
In the planning I wrote that I was going to carry out the experiment twice to gain accurate results. I was only able to carry out the experiment once because we ran out of time do the experiment once again. So I used somebody else’s results, (Rebecca’s and Alex’s results). This may also be a reason for the results not correlating with one another. So the experiment was not carried out in a fair way because I only did it once and used somebody else’s for the second set of results. This does not show accurate results because I do not know whether the other experiment was not carried out in the same method as I did. They may have held their needle and burning food further or closer to the boiling tube. The second set of results were close together for the pasta, crisp bread and dried peas but were not close together on the other three types of food.
Even though I did not produce the best set of results, they still proved that my prediction was correct. The pumpkin seed did release the mot amount of energy out of all the six types of food. Also the dried peas were the food that released the least amount of energy. But my set of results did not show that and the average and Rebecca’s and Alex’s set of results proved this.
In conclusion, the results were not the best set of results that could have been found. But then time was restricted so I was unable to repeat the experiment and do it again for the second time in a fair way. If I had done the experiment the second time around then maybe the results would have been more accurate and I may have been able to draw a line of best fit on my graphs.
Evaluation:
If I was to do this experiment again, I would improve the fact that heat is being lost in the environment and to the glass boiling tube. Condensation would produce on the boiling tube making the boiling tube absorb some heat. Boiling tubes were used and they keep heat in and do not let a lot of it out. So if the boiling tube was weighed before it was tested and then weighed straight after the experiment on a certain food. Then it may prove that not all the heat is in the calculation and that some of the heat goes into the environment. Some of the water could be evaporated into the atmosphere, so once again the boiling tube should be measured to find out whether evaporation did occur and if the water weighs less.
To prevent the above from happening because, that above method is time consuming and to make sure that accurate results are found then, a bomb calorimeter should be used. this is a strong container used for measuring the energy transfer during chemical reactions. A known mass of a substance is burned in the container and energy is released and then it is measured.
