Experiment - Energy in Food
Aim: To determine the amount of energy in a Jatz biscuit.
Diagram:
Method:
1. Set up the equipment as shown in the diagram.
2. Weigh the Jatz biscuit.
3. Measure 10mL of water and pour it into the test tube.
4. Measure the starting temperature of the water and
record it.
5. Light the biscuit and heat the water until the biscuit
has completely burned.
6. Record the final temperature.
7. Calculate the amount of energy in the biscuit and see
if it matches the amount on the packet.
Results:
Biscuit mass:________
Calculations:
Starting temperature:________
Heat = mass x 4.18 x (final temp - starting temp)
Final temperature:_________
= 10 x 4.18 x (final temp - starting temp)
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Class Results:
Do the calculation above to determine the amount of energy your biscuit released as
heat energy and record it in the table next to your group. The teacher will put this table
on the board and write the results of each group into the table. Record the results of
each group as they finish their calculations.
Group
Mass (g)
Start temp (˚C)
Final temp (˚C)
1
4.09
22
100
2
4.10
22
35
3
4.07
22
90
4
3.94
23
29
5
3.99
23
94
6
4.08
23
72
Energy (J)
Use the Nutritional Information table to the right to
see where the energy values have come from.
Find out how much energy your biscuit is expected to release as heat by completing the
following calculation:
Expected Energy = (100/mass of biscuit) x 1 950 000
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QUESTION
Explain why your value was so far off the expected energy value of the Jatz biscuit (did we
catch all of the energy?).
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