Safety Precautions

Wear your safety goggles and wear gloves.

This experiment causes smoke!! Perform this outside, under a kitchen vent, or in a well-ventilated area.

Use cation when cutting aluminum, metal edges can become sharp and cause injury.

Keep away from children and pets.

Chemical Precautions

None

Equipment

Student Supplied Items

Two aluminum cans

Paper clip

Water

Food item (chip, cracker, bead)

Ignition source (lighter, match)

Scissors

Lab Kit Items

Digital scale

25 mL graduated cylinder

Procedure

Note: Please read all steps and safety information before starting the procedure.

Allow yourself enough time to finish the experiment without interruption. The experiment will take at least 3 hours to complete.

Obtain two empty aluminum cans; these will be your calorimeter and holder.

To one can carefully cut a two inch tall by three inch wide opening approximately one inch from the top bottom of the can as shown in the image. This can will be the sample holder.

Make sure the opening is large enough that you can put your food item inside the can, but not so large it compromises the integrity of the can, it needs to be able to hold up the second can (the calorimeter) while full of water.

The second can is your calorimeter, obtain a dry weight and record on your data table.

Add approximately 25 mL of water. Record the new weight. Note that the important data is the mass of the water and not the volume.

Determine the mass of the water.

Obtain a paper clip, bend the paper clip first by lifting the small loop away from the larger loop. Then open the larger loop slighty to form a triangle base. Next open the small loop so that it is pointed out and you can stick a food item on to it, as shown in image.

Make sure the paper clip can fit inside the bottom can opening if your food item was attached and can stand up steadily. If not adjust the paper clip, make sure you have enough room to light the food item, and that the item is close to the top of the can but not touching.

Weigh the paper clip inside the holder (cut can) and record on the data table.

Obtain a food product item (Cheetos, corn chip, bread crust, or cracker), attach it to the bent paper clip( as shown in figure, or however you can secure it), put both paper clip and food item into the holder.

Before placing the calorimeter on top, weigh the holder with the food item and paper clip inside and record the total mass (take a photo for your lab report).

Determine the mass of just the food product. After you burn the food item you will need to re-weigh the holder, paper clip, and ashes to determine how much of the food item was burned.

Make sure the food product is close to the top of the holder so that any heat from the food product burning is transferred to the water inside the calorimeter (the top can).

Using your thermometer measure the initial temperature of the water inside the calorimeter and record on your data sheet.

Carefully place the calorimeter on top of the holder as shown in Figure 3.

When ready ignite your food product. Make sure to burn your food source and try not to get it the flame too close to the calorimeter, you do not want to heat the water with your ignition source.

Once the food product is ignited allow it to burn beneath the water-filled can until the flame goes out.

Measure the new temperature of the water in the can (final temperature) and subtract the initial temperature to find the change in temperature.

Re-weigh the holder, paper clip, and ashes to determine how much of the food item was burned.

Calculate the change in temperature.

Repeat with a new food item of the same type. You may use the same sample of water in the aluminum can after checking the new starting temperature.

Answer all calculation questions below the data table for both trials.

Make sure all items are fully extinguished before tossing in the garbage. You do not want to start a fire. To make complete sure you can always run the ashes under water before throwing out.

Remember to resize and crop all your picture in your lab write up to save space and file size.

Clean, dry and return all lab kit items to your lab kit for later use.

Submission Requirements

You will create a formal lab report using a digital word processing program (Microsoft Word, Google Docs, etc.) and submit it as a PDF within this assignment page.

All lab reports will be organized into three sections:

Design

Title and Purpose

Methodology: Explain the procedure in your own words. What are you doing to achieve the experiment's purpose?

Pre-Lab Questions: These are asked in the "Lab Workbook". Answer in complete sentences.

Results

Observations: Take 2-3 photos of your at-home experiment at crucial points in the procedure and embed them into the digital report. Provide a description of any observations.

Data Tables and Graphs (if applicable): Create digitally, within a word processing or spreadsheet application.

Calculations: Complete all calculations by hand, take photos, and embed them into the digital report. If calculations are involved in the experiment, then they must be provided in this section.

Discussion

Analysis: Explain the point of the lab in your own words. Address the lab's "Purpose" thoroughly, citing and connecting two main sources: your experimental results and your course content.

Post-Lab Questions: These are asked in the "Lab Workbook". Answer in complete sentences.

Instructions For Data Collection

To submit assignment, download the word document, Calorimetry of Food Products.docx, fill in your data.

Answer the post lab questions found after the data tables.

Attach screen shots onto to the word document by using the insert pictures in the tool bar. Remember to resize your images to an appropriate size so that they are easy to see but don't take up a full screen (approximately 2" x 2" is a good size).

Review lab procedures to make sure you have provided all the data, answered all questions in the lab procedures/ post lab, and provided all pictures or observations that were asked for in the the lab procedures.

Submit your data for grading by pushing the "Start Assignment" button in upper right corner and then uploading your word document.

How to Submit an Assignment in Canvas

Calorimetry of Food Products

Name:

Date:

Data Table

	Trial 1	Trial 2
#3)Mass of empty calorimeter
#4)Mass of calorimeter + ~25 mL DI water
#5)Mass of water (4-3)
#8)Mass of holder can + paper clip
#10)Mass of holder can + paper clip + Food product
#11) Mass of food product before burning (10-8)
#13) Initial temperature of Water
#18) Mass of food holder + Food product after burning
Mass of product (17-10)
#17) Final temperature of water
#20) T of water (17-13)

Information and calculations:

Specific heat of water is 4.184 J/gC, Density of water is 1.00g/mL

1 Calorie = 4.184 J, 1 nutritional calorie = 1 Calorie /1000

Calculate the energy (in calories) released by the burning food sample and absorbed by the water.

Q = mCpT

Q = heat absorbed by water, m = mass of water in grams(#5), Cp = 1 cal/g C (Specific heat of water), T = change in temperature (#20)

Q = calories

Determine the number of kilocalories (food Calories) released by the burning food sample (1 kilocalorie, or Calorie = 1,000 calories).

Calculate the energy content of the food in kilocalories/gram.

Using information on the nutrition label of the food sample, calculate the kilocalories/gram. (Divide Calories per serving by the number of grams in a serving.)

Compare your experimentally determined energy content (in kilocalories/gram) to the calculated value from the nutrition label. Calculate the percent error for your experiment. Litture

Post Lab Questions

1. How did the results of your two trials compare? If they differ, is there an explanation for the variation?

2. We are assuming in this experiment that all of the heat energy lost by the food is absorbed by the water. Is this accurate? Explain.

3. How would you improve this experiment?

4. How much heat energy, in calories, is needed to heat 150 grams of water from 20.4C to 50.7C?

5. A 0.37 g Cheeto is burned and the heat produced is used to heat 50 grams of water from 22.1C to 34.4C. What is the energy value of the Cheeto in kcal/g?

6. Why is it necessary to weigh the food product before and after burning?

7. Why is water used as the heat transfer destination, rather than vegetable oil or ethyl alcohol?