1:3:4 Food energy test

Question 1

What are you changing (independent variable of the experiment)

Answer 1

Crisps

Question 2

What will you measure? (Dependent variable)

Answer 2

Temperature

Question 3

Biscuits/crisps may come in all shapes and sizes. How will you keep it a fair test?

Answer 3

Work out the energy per gram (Joales per gram)

Question 4

What equipment will you need for the food energy experiment?

Answer 4

A mounted needle to hold the burning food on
Boiling tube, with 25 g cubed of water
Retort stand
Bunsen burner
Thermometer

Question 4

How will you carry out the experiment?

Answer 4

Measure 25 g of water and pour it into a boiling tube, attach the boiling tube to a retort stand at a 45 degree angle.

Record the initial temperature of the water and take the mass of the food and record.

Carefully put the food onto a mounted needle and place it over a Bunsen burner. As soon as it’s alight, move it under the boiling tube.

When the biscuit stops burning immediately take the temperature of the water and record.

Question 5

What equations do you have to know for calculating the energy?

Answer 5

Energy (J) = Mass of water x rise in temperature x 4.2
Energy in 1 g (KJ/g) = energy released divided by mass of food sample.

Question 6

How can you keep the test valid?

Answer 6

Keep all factors the same except for crisps.

Question 7

List factors that must be kept the same to ensure valid results.

Answer 7

Same amount of water
Same distance from boiling tube
Measure energy based on a gram

Question 8

Why might the energy value obtained be likely to be an underestimation of the energy in the food sample?

Answer 8

Heat energy lost to surroundings/boiling tube
Food might not completely combust when results are taken