LAB18-106 - LAB PDF

Preview

Summary

LAB...

Description

Ankush Sharma 07/08/2019 Lab 18: Calorimetry and Calculation “Burning Food. Where are my carbs? Introduction: The foods we consume on a daily basis give us the energy to allow us to go through the processes of life such as working, studying or even writing a lab report. Within our bodies, the foods we eat undergo chemical changes that convert the nutrients into a form of energy that is more suitable for our body to absorb/intake. This converted energy is used in various different ways in our body. For example, from heat to regulate our body’s temperature, electrical energy for nerve transmissions and mechanical energy that allows us to utilize and move our muscles. In this lab, our goal will orientate towards finding out how companies calculate the amount of calories in their food that they choose to manufacture. The most easiest and common route to notice such a thing would be through the use of a calorimeter in which by maintaining the same pressure, we are able to witness how much energy is within foods when they are burnt. For part 1, the calorimeter constant must be found and then for part 2, we determine the energy content of various snacks provided to us. Materials: Excel, Lab Manual, Notebook to record. Focus Questions: 1) How much energy is released when food burns in the body ? The amount of energy released depends on the energetic content of the food that one has eaten. The amount of energy stored in this chosen food is measured in calories, and each meal will have a different amount of calories. The energy released during the digestion will depend on the kind of meal that somebody will eat. 2) How is the caloric content of food determined ? The caloric content of food is determined by placing the food in a bomb calorimeter in sealed container containing water. Food is burned by electrical source. The raise in temperature of water helps to determine the calorific value of the food that is in the bomb calorimeter. Observational/ Experimental: Part 1: Determining the calorimeter constant. 3 grams of C6H12O6 Delta T is 4.3 C Delta H is -1275 kj/mol -2538*.01665 = 42.263/4.3= -9.829 Part 2: Calculated % error of each sample.

Food Sample

Mass ,g

Initial T(C)

Final T(C)

NRG content

Chan ge T

kJ

kJ/g

cal/oz

% error

Oreo

2.41

26.12

30.92

160

4.8

47.18

19.57

132.64

17.09

Popcorn

2.29

25.76

29.95

130

4.19

41.18

17.98

121.84

6.27

Cheetos

2.21

25.13

30.49

160

5.36

52.68

23.83

161.51

.94

Beef Jerky

2.23

25.89

29.54

80

3.65

35.88

16.08

109.01

36.27

Peanut

2.45

25.64

31.79

170

6.15

60.45

24.67

167.18

1.65

Discussion and Conclusion: In this lab, it was observed how different foods determine the amount of energy is released in the form of heat and how we can determine the patterns in the calorie of energy in these various foods experimented upon. Moreover, it was observed that the highest energy content food usually has more calories compared to foods that have lower calories. Foods with lower calories usually indicated that these foods have low energy content. Importantly, the calories in foods stem from the amount of carbs, fats and protein that that specific food subsisted of. In our experiment, it was found that peanuts have the highest energy content since majority of the calories are coming from the fats. Post Lab Questions: 1) Peanuts had the highest caloric value and this is believed since it is mostly comprised of fat. From my own knowledge, I know that there are 9 calories in each gram of fat and 4 calories in 1 gram of protein and 4 calories in 1 gram of carbs. Overall, I am not surprised by these findings. 2) Peanuts would store the most energy since it contains the most fat. 3) It is important to calculate calories per gram rather than calories burned because calories are a measurement of energy. It would be wise to calculate per gram since it would be more efficient in giving us a correct measure of energy consumed per gram of a food you choose to eat. Moreover, burning food is an afterprocess and it depends on an individual’s metabolism as well. 4) Moles of sucralose= (3.150/342.3) =.009202454 Mass of sucralose 3.150g, T initial 23.42 C, T Final= 27.64C, Heat of Capacity of calorimeter = 4.90kJ/C Qcalorimeter= (4.90kJ/C)*(27.64-23.42)

=20.7kJ -q rxn= -20.7kJ -q rxn= -20.7kJ/3.150g of sucralose= -6.57 kJ/g Find per mole of sucralose -q rxn= (-6.57kJ/g)*(342.3g/mol) = -2.2*10^3 kJ/mol...