CCEA Biology - Nutrition & Food Testing

Question 1

Investigating the Energy Content of Food (steps 1-12)

Answer 1

1. Add water to a boiling tube clamped in a retort stand - - around 20cm^3.
2. Record the starting temp of the water.
3. Place food sample on mounted needle.
4. Ignite the food sample using a Bunsen burner.
5. Hold the burning food sample under the boiling tube of water until completely burned – may be necessary to relight the food sample.
6. Record the final temp of the water.
7. Record results in a table.
8. Calculate: change in temp caused by the burning food sample.
9. Repeat steps 1-8 with this food type to increase reliability.
10. Calculate: average change in temp for this food type.
11. Calculate: energy released by this food type using this equation
    - Energy released (J) = mass of water (g) x rise in temperature (°C) x 4.2
12. Repeat steps 1-8 with diff. food types for comparison.

Question 2

Investigating the Energy Content of Food (first 6 steps)

Answer 2

1. Add water to a boiling tube clamped in a retort stand - around 20cm^3.
2. Record the starting temp of the water.
3. Place food sample on mounted needle.
4. Ignite the food sample using a Bunsen burner.
5. Hold the burning food sample under the boiling tube of water until completely burned – may be necessary to relight the food sample.
6. Record the final temp of the water.

Question 3

Investigating the Energy Content of Food (final 6 steps)

Answer 3

7. Record results in a table.
8. Calculate: change in temp caused by the burning food sample.
9. Repeat steps 1-8 with this food type to increase reliability.
10. Calculate: average change in temp for this food type.
11. Calculate: energy released by this food type using this equation
    - Energy released (J) = mass of water (g) x rise in temperature (°C) x 4.2
12. Repeat steps 1-8 with diff. food types for comparison.

Question 4

Investigating the energy content of food: Equipment Needed

Answer 4

• Test tube
• Thermometer
• Mounted Needle
• Food
• Water

Question 5

Equation to calculate the energy released by the food type

Answer 5

Energy released (J) = mass of water (g) x rise in temperature (°C) x 4.2

Question 6

Investigating the energy content of food: Results

Answer 6

A large increase in temperature indicates the food contains a lot of energy.

Results obtained from this experiment are usually lower than the actual energy content of the food because during the experiment;

the entire food sample may not be burned, some energy is lost to the air and some is used to heat the glass of the boiling tube.

Question 7

Investigating the energy content of food: Controlled variables

Answer 7

• Mass of Food
• Mass of Water
• Distance of food from water