The Amazing Flaming CheezePuff

INTRODUCTION:

In order to change the temperature of something there must be a transfer of energy. To heat up you must add energy, and to cool down you must remove energy. In this activity we will explore the addition of energy to water, which has a specific heat capacity of 4.184 J/g oC. The energy source will be an ordinary cheezePuff. Yes, a cheezePuff. Think about it, we eat food to get energy and if we feel we are eating too much food we start counting Calories. Calories are simply a measure of energy and the average cheezePuff ( 0.62 grams) contains about 2.7 Calories (2700 calories). The main reason for using a cheezePuff is the air flow through the cheezePuff structure. The apparatus used to determine the energy content of food is known as a calorimeter which simply burns the food and measures the resulting temperature change of a sample of water. This information is used with the heat equation:

Q = m cpDT

Q = DTE = “heat”m = masscp = specific heat capacityT = temperature

We will be using a highly simplified and inefficient calorimeter so that we can explore the flow of the thermal energy. 

Preliminary Questions: Answer on your individual paper

1.How many flaming cheezePuffs do you think it would take to boil 1 cup (~255 mL) of water. The water originally is at “room” temperature (~20 oC)

Look at the sample calorimeter provided by your teacher. 

2.What do you think is the source of the input energy?

3.Where do you think the output energy will go?

4.How efficient do you think the calorimeter is?

Available Materials (Get only the materials you need as you read through the procedure):

* 1 coffee can* 1 cheezePuff

* 1 large test tube * 1 food holder (cork and T-pin)

* 1 temperature probe/computer* About 20 mL of water

* 1 graduated cylinder(1 mL H2O = 1 g H2O)

* match(es)* electronic balance – 1 for class

PROCEDURE:

1.Collect all materials, except the match.

2.Set up a data table to record all data. (You must read the entire procedure first to do this!)

3.Set up the coffee can calorimeter according to the teacher’s instructions. Each person should sketch the calorimeter below the preliminary questions.

4.Have your teacher approve your data table and calorimeter before continuing.

5.Record the actual volume of the water to the nearest 0.1 mL

6.Pour the water into the test tube. 

7.Place the cheezePuff on the food holder. 

8.Mass the cheezePuff/holder using the electronic balance. Record this as the initial mass of cheezePuff.

9.Place the temperature probe in the water. Measure the temperature of the water to the nearest 0.1 oC. Record this value as the initial temperature of the water.

*** How to use the temperature probe:

Open the Brain computer on the network and go to the Phy Sci Stuff folder.

·Double click on the cheezePuff icon. If needed

·Click on the Temperature Probe Box and enter the probe calibration number as requested.

This number is on the probe’s cable.

·click on the green “G” button in the toolbar, this will collect temperature data for a maximum of 10 minutes in case you need it. 

10.Have your teacher approve your data before continuing.

11.Place the cheezePuff about 2 cm below the test tube. Remove the coffee can and ignite the cheezePuff. As soon as the cheezePuff is burning on its own place the can back over the flaming cheezePuff. Pay attention to the test tube, the heat may cause it to slip down.

12.After the cheezePuff burns completely, allow the temperature probe to continue collecting data until the temperature starts to go back down. When this happens click the stop button in the top left of the screen. 

13.Save your data as cheeze2002 in your period folder. 

14.Use the graph of the data to determine the maximum temperature the water reached. Record this value as the final temperature of the water.

15.Determine the mass of the burnt cheezePuff/holder using the electronic balance. Record this as the final mass of cheezePuff

16.Have your teacher approve your data before beginning the analysis.

ANALYSIS: Each person should answer each question on your individual paper. Show K-U-E-S where “calculate” is required. 

1.Calculate the change in temperature of the water.

2.  Calculate the mass of the water.

3.What is the specific heat of water?

4.Calculate the amount of thermal energy gained by the water.

5.Have your teacher approve your group’s calculations.

6.Do you think all of the energy released by the cheezePuff went into the water? 

7.Add to your individual sketch of the calorimeter to show the flow of thermal energy during the burning of the cheezePuff. 

8.Calculate the mass of the cheezePuff that was actually burned.

9.Use the actual value of energy/mass contained in a cheezePuff to calculate the amount of energy that is theoretically contained in the mass you burned.

10.Have your teacher approve your group’s calculations.

11.Calculate the amount of thermal energy that did not flow from the cheezePuff into the water.

12.Have your teacher approve your group’s calculation.

13.Calculate the efficiency of the coffee can calorimeter.

14.Have your teacher approve your group’s calculations.

15.What could be done to improve the efficiency of the calorimeter?



Individual Report

Cover Sheet

Title, name, group, group members, date, class period

Individual Work

Preliminary Questions

Calorimeter sketch

Analysis

Data Table – attached to Data Recorder’s Report

Conclusion

Briefly and completely, discuss your answers to the preliminary questions. Basically you are re-answering the preliminary questions, only now you have experimental evidence to support your answers, so an explanation is needed. Be sure to specifically mention the when you have changed your answers.

Evaluation

Write an evaluation of your group’s performance during this lab activity. Specifically address each group member‘s performance of his/her specific job.(1 - 2 paragraph(s) 

Write an evaluation of the lab activity itself (1 paragraph). 

Please provide specific and useful information, not just, “I liked my group….this was a fun lab….”. Also, remember to include supporting evidence for your evaluation, this is a science class not a daytime talk show.