6 Peanut Lab

Energy content of a peanut lab

Background: Everything has a specific heat, which is the amount of energy required to raise 1 g of a substance 1 oC. Scientists used this to determine the definition of a calorie. The definition of a calorie is: the amount of heat energy required to raise the temperature of one gram of water one oC. (Specifically, from 4o C to 5o C).  Calories are listed on most foods so people can determine how much energy they get from foods.

PROCEDURE AND OBSERVATIONS:

1. Reshape a paper clip to hold a peanut about 2.5cm above the base to the ring stand.

2. Adjust the ring to hold the bottom of the pop can about 1-2 cm above the peanut.

3. Mass the empty can to the nearest 0.1g.

4. Add about 100 ml of water to the can and mass the can again. (Subtract the mass of the can from the mass of the can and water).

5. Mass the peanut.

6. Measure the temperature of the water in the can to the nearest 0.1 oC.

7. Place the mounted peanut under the water can. Hold a burning match under the peanut until the peanut burns.  Let the peanut burn completely.

8. Stir the water gently with a swirling motion of the can.

9. Record the final water temperature to the nearest 0.1 oC. Calculate and record the change in water temperature and can temp.

10.  Calculate the number of calories provided by the peanut.

11.  The energy needed to raise heat 1 g of water 1 oC is 1 cal.  Aluminum takes 0.215 cal to raise 1 g 1 oC.

12.  Next, calculate the amount of energy available in one gram of peanut:

Detailed Energy/gram = [Can mass (0.215 cal/g) + Water mass (1 cal/g)] * Temp. change/(Mass of Peanut or chip.)

1. When the word “calorie” is used in reference to food, which actually means kilocalories. A kilocalorie is a unit equal to 1,000 calorie or 1 Calorie. Calculate the number of kilocalories/gram of peanut.

Answer from 12 X 1 kcal/1000 cal. =                  Cal/g or kcal/g.

Theoretical Data=    Peanut = 4.8 Calories/gram

                                Corn Chip = 5.0 Calories/gram

Object

Before

After

Amount change

Mass of Peanut (Corn Chip)

Mass of water and can

XXXXXXXXX

XXXXXXXXX

- Mass of can

XXXXXXXXX

XXXXXXXXX

= Mass of water

XXXXXXXXX

XXXXXXXXX

Temperature of water

Temperature of can

Only do the DATA for the corn chip or the peanut.