Burn Lab

Jordyn Ruff
Chemistry
Ms.Brun
Period 2
5.14.08
Title: Burn Lab
Date: 5/6/08
Purpose: To find out how much energy food has, also to determine better results and                                                       error percentage.
Procedure:

Data:
| Item burned: potato chip | Item burned: Marshmellow |
Mass of 50mL of distilled H20 | 15g | 15g |
Mass of evaporating dish | 44.42g | 44.42g |
Initial Mass of Food item (before burning) | 1.2g = 45.6g | .6g = 45g |
Final Mass of Food item (after burning) | 44.6 | 44.65 |
(Use math) Change in mass of Food item | .8g | .4g |
Initial temperature of H20 | 24 degrees C | 26 degrees C |
Final temperature of H20 | 49 degrees C | 30 degrees C |
(Use math) Change in Temp | 25 degrees C | 4 degrees C |

Calculations:
  1. Q=M*C*delta T
Q= (15)(4.18)(25degrees C) = 1567.5 J
  2. 1567.5J/1 * 1 cal/4.18 = 375 cal
  3. 375 cal/1 * 1/1000 cal = .375 Kcal
  4. 44.6g – 45.6g = .8g
.375 Kcal/ .8g   = .468 Kcal/g
  5. (.468 Kcal/g/ 1g)*28g = 13.10 Kcal/28g
  6. 150cal/28g vs. 13.10 Kcal/28g
  7. 150-13.10/150 * 100 = 91% error

Discussion:
  1. The process is exothermic because the chip is giving off energy to the test tube.
  2. The chip was not completely consumed, there was still chip there, and not all of the chip can be used for energy.
  3. The heat was given off everywhere. There could be a funnel system to direct the heat to the test tube allowing more heat to the test tube.
Conclusion: In this lab we showed how many calories certain foods gave off. We also tried to figure out more efficient ways to complete the lab. I learned that not all parts of food can be used for energy. There should be a way to channel the heat given off by the chip to the test tube filled with water.