CONCEPT:
Energy is created when objects are burned.
OBJECTIVE:
To determine the numbers of calories in various products.
MATERIALS:
- graduated cylinder
- metal cup
- burner
- sparker
- clamp and stand
- thermometer
- tongs
- corn products (snack food)
KEYWORDS:
endothermic, exothermic, isothermic
BACKGROUND:
By burning food, one can determine the calories produced. The
calories equal the mass of the water multiplied by the change
in temperature. A kilocalorie = 1000 calories. 1 ml. of water
has an approximate mass of 1 gram. A calorimeter is a device
to do this process. Exothermic means produces energy, endothermic
means absorbs energy.
PROCEDURE:
1. Determine the mass of a JAX (a snack
food). Record on table.
2. Clamp the sides of the metal cup
to the stand.
3. Measure out 50 ml. of tap water
and put it into the cup.
4. Determine the temperature of the water and record it below.
5. Light the burner. Hold a JAX at
one end with the tongs.
6. Ignite the other end and then quickly
place it under the metal cup. Keep it there until all the JAX
is burned. (Note: if the flame goes out, reignite it and continue.)
7. Determine the highest temperature
for the water and record it.
8. Calculate the number of calories
produced.
(# cal. = t x mass of water)
where t = temperature change
9. Repeat the procedure with fresh
tap water and a DOODLE, then a BUGLE.
Data
Food Mass (g)
Temperature Initial
Final
Temp. Change
Mass Water
#Cal. Produced
cal./g (food)
JAX
DOODLE
BUGLE
Analysis:
1. Which product produced most calories/g.?
__________
2. What is the number of kilocalories
produced by the JAX?_______; the DOODLE?________; the BUGLE?______.
3. If a bag has 200 JAX, how many kilocalories
will be produced? ________; 200 DOODLES? ________; 200 BUGLES?
_________.
4. All the reactions were (exothermic,
endothermic or isothermic). Circle answer.