Calorimetry

• What is the aim of the experiment described in the text?

  To measure energy in different foods
• How will the energy given off by burning food samples be used in this experiment?

  To heat up water
• What measurement allows the calculation of energy content in the food sample?

  Temperature rise of the water
• What apparatus is needed for the experiment?

  • Test tube
  • Clamp and stand
  • Mounted needle
  • Thermometer
  • 20cm³ measuring cylinder
  • Bunsen burner & heatproof mat
  • 250 ml beaker
  • Balance
  • Food samples
• What is the first step in the method described?

  Put 20cm³ of water into a test tube
• What volume of water should be added to the test tube?

  20cm³
• What should be recorded after adding water to the test tube?

  The temperature of the water
• What measurement of the food sample should be recorded?

  Its mass
• How is the food sample held for burning?

  On the end of a mounted needle
• How should the food be ignited?

  By holding it in the Bunsen flame
• Where should the burning food be held once alight?

  So the flame touches the test tube
• What should happen if the flame goes out?

  Quickly relight the food
• What should be done with the food sample after it stops burning?

  Drop it into a discard beaker
• What action is important to take just before recording the final temperature?

  Stir the water in the test tube
• What should happen after the final temperature is recorded?

  Repeat with a different food