FAIR TESTING: Fair testing is extremely important in this experiment because we are going to compare the different types of peanuts to each other and if it wasn’t a fair test it will give us inaccurate results. So these are thing that we did to ensure that our experiment was fair.
- As we are using two clamps, one for the test tube and one for the needle, we made sure that the clamp with needle was 1.5 cm away from the bottom of the test tube at all times.
- We use 10ml of water each time we tested a peanut.
- We used peanuts of the same weight, 0.3g each peanut.
-
We start the experiment with the same temperature of 18oC each time.
- We did the experiment of the same type of nut three times so that we could take an average reading.
- We moved the Bunsen burner right out the way so the water in the test tube only gets heat from the burning peanut, not the Bunsen burner.
- We only lit each peanut until there was a visible flame coming from the peanut.
APPARTUS LIST: Here is a list of all the equipment we used and why we used them.
- Bunsen burner- to heat the peanut.
- Test tube- to hold the 10ml of water we are using.
- 2 x Clamps- to hold the test tube and to hold the needle.
- Heat proof mat- to put the Bunsen burner on.
- Needle-to hold the peanuts in place.
- Peanuts- to burn.
- Thermometer- to take temperature readings.
- Stopwatch- to take time readings.
- Water- to put in the test tube.
- Measuring Cylinder- to measure the amount water we used.
METHOD: Here is a step by step guide of how to do the experiment.
- Collect the apparatus which includes test tubes, a Bunsen burner, a thermometer, a needle, clamps etc. (See apparatus list)
- Set out the apparatus with the two clamps opposite each other, a test tube in clamp and the needle in the other clamp. Put the thermometer inside the test tube and finally put the Bunsen burner on a heat proof mat and leave it behind the clamp.( If unsure how to set out the experiment see diagram below)
- Measure out 10ml of water with the measuring cylinder and put it in the test tube. Always use 10ml of water each time the experiment is done to ensure that it is a fair test.
- Collect the three different types of peanut and weight them to make sure they weight 0.3g this is ensure it is a fair test.
- Pierce the peanut with needle without damaging the peanut and not cutting yourself and put in place in the clamp.
- Adjust the clamp each time you do the experiment that the tip of peanut is 1.5cm away form the bottom of the test tube this is to ensure it is a fair test.
- Light the peanut with the Bunsen burner until the peanut is able burn by itself and switch off the Bunsen burner to stop any inadvertent heat going to the test tube so it is a fair test.
- Whilst the peanut is burning take temperature reading every 10 second so a line graph can be drawn.
- Do the experiment 3 times so an accurate average can be taken.
- Tabulate all the results and work out an average result by adding the three results for each time reading divide it by 3. I.e. if your results for the first 10 seconds was 19, 18, 20 what you do is add 19+18+20=57 and divide it by 3 which equals 19.
- Draw the line graphs and draw lines of best fits.
-
Use the equation E=M0 ∆t to work out the energy in joules. To convert the energy from joules to kilo joules you divide the number of joules by a 1000.
- Line graphs can be drawn from this information as well.
- To see how much energy is in a 100g you do 100 divide weight of peanut and time it by energy in joules. When you get the answer divide it by 1000 to get the Energy in KJ per 100g so you can compare it packaging.
- How to set the experiment up
DryRoasted Peanut
ATTEMPT 1 weight before: 0.3g weight after: 0.0g
ATTEMPT 2 weight before: 0.3g weight after: 0.0g
ATTEMPT 3 weight before: 0.3g weight after: 0.0g
Average weight before: 0.3g weight after: 0.0g
Roasted Peanut
ATTEMPT 1 weight before: 0.3g weight after: 0.0g
ATTEMPT 2 weight before: 0.3g weight after: 0.0g
ATTEMPT 3 weight before: 0.3g weight after: 0.0g
Average weight before: 0.3g weight after: 0.0g
Plain Peanut
ATTEMPT 1 weight before: 0.3g weight after: 0.1g
ATTEMPT 2 weight before: 0.3g weight after: 0.2g
ATTEMPT 3 weight before: 0.3g weight after: 0.0g
Average weight before: 0.3g weight after: 0.1g
DRY ROASTED PEANUT
ATTEMPT 1
ATTEMPT 2
ATTEMPT 3
ROASTED PEANUT
ATTEMPT 1
ATTEMPT 2
ATTEMPT 3
PLAIN PEANUT
ATTEMPT 1
ATTEMPT 2
ATTEMPT 3
AVERAGE GRAPHS
DRY ROASTED PEANUT
ROASTED PEANUT
PLAIN PEANUT
To calculate the energy there is a special equation to do so and in this section we will calculate the energy for each of the different types of peanuts. With these results a bar graph can be drawn and we can also work out the energy per a 100g and compare our result to packaging.
E=mQ∆t
E is the energy in joules and to convert joules into Kilo joules you divide the number of joules by a 1000.
M is the mass of the water we used which in our case was 10ml.
Q is a specific heat capacity of water which is 4.2; this is how much energy is needed to raise a kg of water by 1oC. It is different for different liquids.
∆t is the temperature change and to work this out you temperature at the end minus temperature at the start. This should give temperature change.
If you are still unsure here is a worked example.
If when I burned the peanut the finishing temperature was 400C and the starting temperature was 30oc and I used 10ml of water what was the energy in KJ?
E= mQ∆t
E= (10) X (4.2) X (40-30)
E= 42X10
E=420J
E= (420/1000)
E= 0.42 KJ
- CALCULATIONS OF ENERGY IN DIFFERENT PEANUTS
Dry Roasted Peanut
Attempt 1
E= mQ∆t
E= (10) X (4.2) X (44-18)
E= 42X26
E=1,092J
E= (1092/1000)
E= 1.092KJ
Attempt 2
E= mQ∆t
E= (10) X (4.2) X (45-18)
E= 42X27
E=1,134J
E= (1134/1000)
E= 1.134 KJ
Attempt 3
E= mQ∆t
E= (10) X (4.2) X (42-18)
E= 42X24
E=1,008J
E= (1008/1000)
E= 1.008KJ
Average
1092+1134+1008=3234/3=1078/1000= 1.078 KJ
Roasted peanut
Attempt 1
E= mQ∆t
E= (10) X (4.2) X (46-18)
E= 42X28
E=1,176J
E= (1176/1000)
E= 1.176KJ
Attempt 2
E= mQ∆t
E= (10) X (4.2) X (48-18)
E= 42X30
E=1,260J
E= (1092/1000)
E= 1.260KJ
Attempt 3
E= mQ∆t
E= (10) X (4.2) X (41-18)
E= 42X23
E=966J
E= (966/1000)
E= 0.966KJ
Average
1260+1176+966=3432/3=1144/1000=1.144KJ
Plain Peanut
Attempt 1
E= mQ∆t
E= (10) X (4.2) X (42-18)
E= 42X24
E=1,008J
E= (1008/1000)
E= 1.008KJ
Attempt 2
E= mQ∆t
E= (10) X (4.2) X (39-18)
E= 42X21
E=882J
E= (882/1000)
E= 0.882KJ
Attempt 3
E= mQ∆t
E= (10) X (4.2) X (49-18)
E= 42X31
E=1,302J
E= (1302/1000)
E= 1.302KJ
Average
882+1302+1008=3192/3=1064/1000=1.064KJ
Here is a dual bar graph to show energy in joules for all the different types of peanuts
Here is another graph to the average energy in joules.
- WORKING OUT ENERGY PER 100g
We have already worked out the energy for 0.3g of peanuts and now we will want to work out energy per a 100g. To do so you 100 divide by 0.3 and you multiply that number to the number of joules and with that number you divide it by a 1000 to give the amount of energy in a 100g in KJ. We are going to use the average number of joules for each type of peanut.
If a peanut weighed 0.3g and I had worked the energy to be 1000 Joules how much energy in KJ would be in a 100g of peanuts?
100/0.3= 333.33
333.33 X 1000=333330
333330 Joules
333330/1000=333.33 KJ of energy in a 100g of peanuts
DRY ROASTED PEANUT
100/0.3= 333.33
333.33 X 1078=359329.74
359329.74 Joules
359329.74/1000=359.33 KJ of energy in a 100g of peanuts
ROASTED PEANUT
100/0.3= 333.33
333.33 X 1144=381329.52
381329.52 Joules
381329.52/1000=381.33 KJ of energy in a 100g of peanuts
PLAIN PEANUT
100/0.3= 333.33
333.33 X 1064=354663.12
354663.12 Joules
354663.12/1000=354.65 KJ of energy in a 100g of peanuts
- In the experiment the roasted peanut heated the water to the highest temperature. We know that it contained the most energy because when I worked out the amount of KJ in the peanut the roasted peanut came out on top. The roasted didn’t just heat the water to a high temperature once but it was very consistent in doing so, we know this because on my graph for the average energy for the different types of peanut the roasted came out on top again whereas the other peanut got only one high temperature and the rest were low but all of the roasted peanut temperatures were high.
- In my hypothesis I knew that the roasted peanut would have the highest energy this is because of I looked on the back of packet of roasted peanuts and it had the high fat content. As I have already mentioned fat contains a lot of energy so it is quite obvious that the peanut that contains the most fat would contain the most energy.
-
An anomaly that I found was that in experiment the plain peanut only heated the water to 39oC I found that odd because the other plain peanuts heat there peanut to above 40oC when they all weigh the same . The reason I think this may have happened is that they wind may have blew out the peanut as we know that that this particular peanut didn’t burn to it’s full ability because when we weighed it after the experiment it still weight 0.2g whereas when we weighed the other peanuts some of them weighed nothing which mean they used all their energy.
- From my results I know that the roasted peanut had the greatest amount of energy we know this because it heated the water up to the highest temperature. We also know this because when use the equation for energy content, E=mQ∆t, tells use as well that roasted peanut contains the most energy compared to the other peanut. In fact it contains 36 Joules more compared to the rest.
- In our experiment we were going to use a dried pea but we decided to discount it for two main reasons. Firstly when we tried to get the needle inside the pea it was extremely hard and secondly when we eventually got when needle inside the pea it wouldn’t burn in the Bunsen, so we decided to discount it. The reason why the pea didn’t burn is that it doesn’t contain any fat so it doesn’t have any energy to burn thus why it wouldn’t catch alight.
- The trends in our experiments that the plain peanut burned for the longest but didn’t heat the water to the highest point whereas the roasted peanut heat the temperature to the highest point but never burned for the longest. This may be down to the fact that they contain different amounts of carbohydrates which also give off energy. The plain peanut most probably contains more carbohydrates than the roasted peanut so when the carbohydrates burn they give off less energy compared to fats. So if the plain peanut contains more carbohydrates it would have burned for longer but with less energy than the roasted peanut’s. Whereas the roasted peanut which contains more fats but with less carbohydrates would have burned for less but more energy due to the fats hence heating the temperature of the water higher.
- I don’t think that our results fully supports our prediction because we thought that the peanut with the most energy would burned for the longest but in fact it was a little bit different to that because the plain peanut burned for longer than the roasted peanut but the roasted peanut got the higher temperatures of the water. As I have already mentioned this may be done to the fact that they contain different amounts of carbohydrates.
- EVALUATION
-
In our group of three I think that we found that experiment quite easy and I also think that the quality of our results were also good given the resources. An anomaly that I found was that in experiment the plain peanut only heated the water to 39oC I found that odd because the other plain peanuts heat there peanut to above 40oC when they all weigh the same . The reason I think this may have happened is that they wind may have blew out the peanut as we know that that this particular peanut didn’t burn to it’s full ability because when we weighed it after the experiment it still weight 0.2g whereas when we weighed the other peanuts some of them weighed nothing which mean they used all their energy.
- An improvement that I would like to make is to test peanuts which weighed different amounts to each other so it would give a greater idea of the energy stored in the different types of peanuts.
- Our results were quite reliable but there is always human error when reading off the thermometer or when using a measuring cylinder to see how much water to use. So the best way to make the results more reliable is to use digital thermometers and digital measuring cylinder, if they exist.
- Further experiments we can do is use different food stuffs, use foods that have been cook in different way i.e. compare a food stuffs cooked in lard compared to food cooked in oil. But the one I am going to write about is using a product i.e. A chocolate bar and test it against the same type of chocolate bar but a low fat version. What we hope to find when this experiment is done is that the normal chocolate bar will heat the water to a higher temperature due it higher fat content .As fats are used for respiration, the usage of energy, so a substance with a high fat content will respire for longer hence it will burn for longer.
