1. Calorimetry

2. Objectives Determine the number of calories in types of foods.
Calculate the percent error between the experimental and actual value.

3. Calories
Calorie: The amount of energy required to raise 1 gram of water by 1 degree Celsius
Our cells NEED energy to function
The energy in food is converted to energy the body can use
Calories measure how much energy the body will get from the food

4. Calorimetry The process to measure the amount of calories in food
1000 chemistry calories = 1 kilocalories
1000 calories = 1 Calorie
1 Calorie = 1 food calorie

5. Charts Measurements Sample 1 Sample 2 Food used Mass of empty can (g)
Mass of empty can (g)
Mass of can plus water (g)
Minimum temperature of water (°C)
Maximum temperature of water (°C)
Mass of Weigh Boat(g)
Initial mass of food (g)
Final mass of food (g)

6. Initial Directions Weigh the mass of the empty can
Record the mass
Fill the can with 50 to 1000 mL of water
IF THE BALANCE SAYS ERROR, POUR SOME OF THE WATER OUT!
Re-weigh the can with the water
Make a weigh boat from aluminum foil
See example at the front of the room
Measure and record the mass of the weigh boat
Choose one food sample
Weigh the mass of the food sample in the weigh boat
Initial mass of food = total mass – mass of weigh boat
Setup the calorimetry as shown in the next slide

8. Directions 2 Open Logger Pro Click open and open the biology folder
Open the program 01Energy in Food
Connect the temperature probe using the LabQuest mini
Change the length of the experiment to 10 minutes
DO NOT TIGHTEN THE PROBE TO TIGHTLY!!!

9. Directions 3 Click the green arrow
Let the temperature run for 30 seconds
THIS IS YOUR INITIAL TEMPERATURE
Away from the stand, let the food with the match.
Place the dish under the center of the can
ONCE THE FOOD BURNS OUT DO NOT RE-LIGHT IT
This will ruin the experiment
Just let the experiment continue to run!!!
If the temperature goes above 60˚C, then blow out the food
This will ruin the temperature probe

10. Directions 4
Once the entire experiment is complete, click on the Stat button
Record the MAXIMUM Temperature
Clean-up:
Throw away the dish, food samples, and cans
Put the probe, ring stand, cork, and clamps on the back shelf
Finish the calculations

11. Calculations Mass of water (g) Change in temperature of water (°C)
Sample 1
Sample 2
Mass of water (g)
Change in temperature of water (°C)
Change in mass of food sample (g)
Energy gained by water (chemistry calorie)
Energy content of food sample (chemistry calorie per gram)
Energy content of food sample (food calorie per gram)

12. Conclusion Questions
Which of the foods tested had the greatest energy content? 
Which of the tested foods is the best energy source? Explain your reasoning for your response.
Why might a food with lower energy content be a better energy source than another food with higher energy content?