ch16 peanut lab

CALORIES IN A PEANUT NAME_________________PD____

PURPOSE:

Determine, by experiment, the # calories per gram in a peanut; then find % error by comparing to the calories per gram on the peanut can.

DISCUSSION:

Because energy is conserved, the heat the peanut gives off as it burns should be equal to heat the water gains as it is heated by the burning peanut. Calories is another energy unit; 1 Calorie = 4180 joules. Heat in joules can be calculated by q=m*changeT*Cp.

PROCEDURE :

As described.

DATA:

Trial mpeanut Tiw Tfw mw Cpw Cal per serving g per serving

CALCULATIONS:

Trial Tw qw in j q in Cal exp cal/g act cal/g % error

Calculations:

Trial change in Tw qw in j q in Cal exp cal/g act cal/g % error

Calculations:

CONCLUSIONS:

1. What is your average % error?

2. What are some sources of error?

3. What do you think the black stuff is?

4. Why does the peanut burn so well?

5. Why are peanuts ‘nutrition in a nutshell?

6. Which supplies more energy a gram of fat or a gram of carbohydrate?

7. Which supplies more energy a peanut or a piece of bread of the same mass?

8. Why would Eskimos eat whale blubber?

9. What type of change (physical or chemical) was involved in this lab?

10. What type of change was involved in the specific heat of metals lab? (Apes - heating soil)

11. Which type of change involves a greater energy transfer?

12. What is food that we consume used for?

13. Where did the stored energy in the peanut come from?