Nutrition (Human Diet)

Question 1

Outline an experiment to test for the energy content of a food sample

Answer 1

• Record the starting temperature of a specific volume of water
• Weigh the mass of the food sample
• Place food sample on mounted needle underneath the test tube of water
• Completely burn the food by lighting it with a bunsen burner underneath the tube
• Record the final temperature of the water
• Repeat with different food samples
• A larger increase in temperature per mass of food indicates a larger energy content in the food

Question 2

How do you work out the amount of energy in a food sample?

Answer 2

Energy transferred = 4.2 x Temp. Increase x Mass of water/Mass of food sample

Question 3

Why might the result you got for the energy of the food sample be less than it really is?

Answer 3

• Heat convects around the test tube
• The test tube conducts some of the heat
• Heat radiates out of the water
• The burning of the food may have been incomplete