Paper 2 - Nutrition

Question 1

Describe a practical to investigate the energy content in a food sample

Answer 1

• Measure the mass of a sample of bread
• Put 20cm3 of water in a boiling tube
• Place a thermometer in the boiling tube and record the initial temperature of the water
• Place the sample of bread on a mounted needle and light the bread sample in a Bunsen flame
• Quickly move the burning bread sample and place it directly under the boiling tube
• If the bread stops burning, relight the bread in the Bunsen flame
• Repeat until the bread does not burn
• Record the final temperature of the water in the boiling tube

Question 2

Why could energy on a packet be different to energy measured by a student?

Answer 2

Not all energy is used to heat the water because it is lost to the surroundings

Question 3

How could energy loss be reduced in a calorimetry experiment?

Answer 3

Insulate the boiling tube