Peanut Experiment

The Peanut Experiment

Aim

To find out how much energy there is in 1 gram of peanut

Theory

Our bodies need a lot of energy. We use energy to move, keep our body warm and grow. If we exercise our body we lose a lot of energy ,although we use up energy all the time, even when we sleep. We get our energy from food. Especially foods that are rich in carbohydrates, fats, and protein. The amount of energy in food is measured in kilojoules (kJ). In the United States we measure energy in kilocalories, also known as calories. One calorie is equal to 4.2 kilojoules.
In this experiment we are going to measure the amount of energy in 1 gram of peanut. To find out the amount of energy, we will burn a peanut and see how much the temperature of the water rises. You multiply the rise of temperature by the mass of the water. If you multiply it by 4.2 you convert the amount of energy from calories to kilojoules.

Apparatus

Peanut, pointer, Bunsen Burner, balance, test tube, clamp stand, measuring cylinder, thermometer

Diagram

Procedure

Using a measuring cylinder, 20 cm3 was added to a test tube. The test tube was the clamped to the stand. A thermometer was put in and the temperature of the water was taken and recorded. The mass of the peanut was found using a balance. The peanut was placed on the pointer. The peanut was held in the Bunsen burner’s flame until it started to burn. Then we put it under the test tube as quick as possible. When the peanut stopped burning, the temperature of the water was taken again. Then the experiment was repeated using a new test tube and peanut.

Data

Experiment A Experiment B

Mass of peanut 0.4 g 0.3 g
Temperature at start 24 C 19 C
Temperature at end 41 C 42 C

Conclusion

There are 6.65 kJ in one gram of peanut.

Discussion

Food scientist estimated that the energy in one gram of peanut it 24.5. That is much higher than our group’s or even our class’ average. But there are many things that could have gone wrong. It starts when putting the peanut in the fire. You can’t really tell if it’s on fire or not and if you keep it in too long your wasting energy in the peanut. The same counts for moving the Bunsen burner to the test tube. The fast movement causes the fire to become smaller and it takes too long to get it to the test tube, again, losing energy. Also, in some cases the peanut went out. This was a big loss of time and the water could cool down in those seconds you’re trying to relight it. One of the reasons the fire could go out is because people keep on walking by. Another big reason is that it is a lot more sophisticated in a real laboratory. Everything is very precise and perfectly thought out. They try it many more times, making it more accurate. They might have better apparatus and they probably spent time thinking about what kind of peanut. The peanuts we used might have been old. It also might matter what kind of peanut you use. After the experiment there was probably some oil left in the peanut that wasn’t burned yet. Although we did a very good job, I think there is a better way to do. If we did it in the same conditions as the food scientist we would have probably got the same amount of kJ/g of peanut. Also, if we took the reasons into consideration, even in our own lab, we could have had a more sophisticated, accurate result.