Lab Report Caloric Content of Food free essay sample

We learned from the chapter that a â€Å"calorie: is a unit of energy, just like a kilowatt-hour or a joule. These units, represent the amount of â€Å"heat energy† it takes to raise the temperature of one gram of water by one degree Celsius. When we burn the food items and capture the heat in the water, we will use the following formula, our initial and final temperatures and we can calculate the energy released from each food item. FORMULA: Q = t*m*cp Q= heat energy absorbed t = change in temperature ,? C m = mass in grams, g cp = specific heat capacity ( 4. 184 j/g ? C for water) It states clearly that there will be considerable error in this experiment, due to some of the heat given off from the food being burned, and it was absorbed by the glass beaker and some energy escaped into the air. This gave us results that are lower than the accepted values. PROCEDURES: After gathering my equipment from the labpaq and required items from my home. I started with my measurements. I first measured my 100mL empty glass beaker on my scale from the labpaq and recorded that in data table 7. 1. Next I filled the beaker with 50mL of tap water, I measured the water and the beaker together and recorded those measurements as well. Next, I used my sheet of aluminum foil and placed my burner stand on it and placed my beaker with the water upon the stand and placed my thermometer into the beaker, after a minute or so I took a initial measurement of temperature of the water and recorded it. Now I needed to get a mass measurement of my first item, for the experiment. I started with the marshmallow and a fork. I took a mass measurement of the marshmallow and the fork separately and recorded it in data table 7. 1 Next I placed the marshmallow on the end of my fork and then I weighed those two together and recorded my measurement. Now it was time to add the heat, I used a extended grill lighter for my heat source. I clicked the lighter and carefully placed the marshmallow into the flame, once it caught and started to burn, I placed the burning marshmallow under my beaker, while allowing it to burn most of the way down, I had my oldest daughter help me stir the thermometer in the beaker. Once it had burned out, I took a new measurement of the fork with the burnt residue on it and recorded that measurement. I set the fork in the sink and checked the temperature of the water in the beaker, and recorded the final temperature. There is cleanup in between each food item to be burned, and you must start with fresh water and a new initial temperature for the remaining items in the experiment. I followed the above steps for the walnut and the potato chip and recorded their measurements in the data table 7. 1 as well. Once all my food items were burned , measured and recorded. I then proceeded to my calculations for analysis in this lab and recorded the remaining results in the data table 7. 1 below. DATA TABLE 7. 1 CALORIC CONTENT OF FOOD/ OBSERVATIONS FOOD ITEM DESCRIPTION|MARSHMALLOW|NUT|POTATO CHIP| Mass of food and holder-initial|40. 4g|18. g|16g| Mass of food and holder-final|38. 8g|16. 3g|13. 5g| Mass of food burnt|1. 6g|2. 0g|2. 5g| Mass of beaker|66. 5g|66. 4g|66. 5g| Mass of beaker and water|107. 2g|108. 2g|108. 2g| Mass of water|40. 7g|41. 8g|41. 7g| Water temp. initial|23 °C|22 °C|22 °C| Water temp. final|31 °C|72 °C|32 °C| Delta T  °C, change|8 °C|50 °C|10 °C| CONCLUSIONS: Altho ugh I still do not like â€Å"burning things†, this one was rather neat. I am overweight and lately have really been watching calories, and by doing this experiment I have grasped a better understanding of how energy Is released from food and how to properly calculate caloric content. Although I do not believe I will be using any of these methods to calculate my caloric intake, I will just stick to my labels provided for me and hope that they are without error. ANSWERS TO END OF LAB QUESTIONS: A. The food that tested with the most energy per gram was the potato chip. B. My results were somewhat lower than the averages, but according to the discussion prior to the lab it stated that this would be a possible issue, due to the heat loss in the air, and the beaker absorbing some of the heat as well. C. The type of reaction used in calorimetry, would be a â€Å"combustion reaction†, which we learned about back in chapter 5. A chemical process may either absorb or release energy, and many times this energy is in the form of heat. In experiments we often need to know how much heat is absorbed or released when such a process takes place. The measuring of that heat is known as . calorimetry determines how much heat is absorbed or released by noting the temperature before and after the process. By determining the temperature difference, we are then able to calculate how much energy was absorbed or released. In order to measure the amount of heat a reaction absorbs or releases, a calorimeter is often used. calorimeters are sometimes used in calorimetry to calculate the heat gained or lost in a combustion reaction. D. The products from the reactions are CO2 and H2O. E. The products were released into the air, or the atmosphere. F. 1. In using the data that the student collected about the cashew nut, we would calculate the total energy released by the combustion of the nut by using the increase n temperature of the water, the mass of the water and the specific heat capacity of water. We will use this formula: FORMULA: Q = t*m*cp 58576 joules 2. In order to calculate the energy released per gram of the cashew nut consumed in the reaction we calculate as follows: 58,576j / 0. 55g = 106502 / 4. 184 = 25455 or 2. 5 cal 3. Using given standards, my favorite snack food Chili Cheese Fritos (snack bag size) caloric content is as follows: Carbohydrates: 60 proteins: 8 fats: 90 a second conclusion is I need to find a snack food with less fat!