Workshop 11 : Pop Can Calorimeter
- LCHS Physical Science
 LCHS Main SiteSD271 Main siteUof I New Century Classroom  
Objectives: The learner will...
...recognize and use temperature units
...demonstrate use of measurment equipment
...work problems involving specific heat with a hand-made can calorimeter
 
Purpose:
Using the equation [ Heat = mass x c (heat capacity) x temperature ],
an aluminum pop can, a foil "skirt", 100 grams (milliliters) water, a Celsius thermometer, a gram scale, graduated cylinder, a paper clip "skewer" and hanger (2), some dry high calorie snack food (e.g. Cheetohs or Doritos), and matches (or lighter), you will make a calorimeter that measures dietary calories.

Setup:
    Since the heat ( calories) from the burning food will go into both the can-skirt and the water the equation becomes:
     

    (can-skirt)

    (water)
    Heat (cal)= mass x c x temp + mass x c xtemp
        mass = 100 grams (mL)

    The water is in direct contact with the can so temp is the same for both! Also, a dietary calorie equals 1000 lab calories giving us our FINAL EQUATION:
    (mass of can-skirt) (temp)
    Heat (cal)= (m x .22 + 100 ) x (T2 - T1) / 1000

    the can & skirt both have a heat capacity of .22 (cal/g-C)
Procedure:
First, using information from the snack package, determine how many calories are in a small sample approximately equal to 1/4 a chip/cheetoh (a larger sample will burn too fast and incompletely),
e.g. 100 calories per serving, 1 serving = 20 chips, using 1/4 chip, then 100 / 20 / 4 = 1.25 calories

Use the gram scale to find the mass of the can and skirt
m =
ADD EXACTLY 100 mL (grams) of water in the can using the graduated cylinder and record the temperature:
T1 =
Carefully skewer your food sample, go outside in an area sheltered from the wind, light the sample with a match or lighter (under teacher supervision), hold burning sample under can until it is completely charcoal. If it doesn't burn completely, empty the water and start over :(
Slowly stir the water with the thermometer for 1 minute then record the final temperature:
T2 =

Now, use the FINAL EQUATION above and your experimental data to calculate the calories in the sample:

Compare your experimental calculations with your package calculations and comment about possible error sources:


Conclusion:
Finally, show the instructor a hardcopy of this experience including all the above data for your grade.