Calories in a Peanut Lab
Name_______________________________
25 Points
Period_______Date____________________
Purpose: To determine the energy content in Calories per gram of peanut.
Materials:
triple beam balance
cold water
ring stand & ring
graduated cylinder
aluminum can
glass stirring rod
paper clip
matches
thermometer peanut
Procedure:
1. Put on your goggles and apron.
2. Obtain ½ peanut on a paper clip tripod (or cork) and weigh. Record the mass to the nearest 0.01 g.
3. Obtain an aluminum soda can from the lab supply table. Wipe off any residue from the
bottom with a wet paper towel.
4. Obtain about 100 ml of cold ice water from the lab bench with a beaker.
5. Measure exactly 100.0 ml of cold (around 10.0 C) water with a graduated cylinder into an
aluminum soda can. Record the mass of the water to the nearest 0.1 g.
6. Measure and record the initial temperature of the water to the nearest 0.1 C.
7. Set up the aluminum can with the ring stand and stirring rod as shown. Adjust the ring so that
the can is within 2 cm from the top of the peanut on the paper clip (or cork).
8. Light the peanut with the matches while it is under the can and allow it to burn until it goes out
by itself.
9. Quickly measure the final temperature of the water in the can (the highest temperature it
reaches) and record it to the nearest 0.1 C.
10. After the peanut has cooled measure and record the final mass of the peanut and the paper
clip to the nearest 0.01 g.
11. Return the can and paper clip (or cork) to the lab supply table, discard the remaining peanut, clean up
your area, wash your hands and complete the calculations.
Data Table: (8 pts)
Mass of peanut & paper clip before
g
Mass of peanut and paper clip after
g
Mass of peanut burned
g
Volume of water
Mass of water
mL
g
Initial temperature of water
C
Final temperature of water
C
Change in temperature of water
C
Calculations:
1. Calculate the amount of heat absorbed by the water in the can (the amount of heat given off by
the peanut) in calories. Remember to use the specific heat of water as 1.00 cal/gC (5 pts)
q(sur) = mCpT
2. Remember 1000 calories = 1 kcal = 1 Calorie. How many food Calories were given off by the
peanut you burned? (1pt)
3. Determine the Calorie content per gram of peanut. Assume that the water absorbed all of the
heat released by the peanut. (4 pts)
4. The expected value for the Calorie content per gram of peanut is 6.00 Cal/g. Calculate the %
error for your experiment. (5 pts)
5. If your value does not equal the accepted value, consider if the number of Calories absorbed
by the water represents all of the heat released by the burning peanut? Explain your answer.
(2 pts)