Calorimetry

Explain the experiment for finding energy in food

1. Take a small amount of dry food (burns easier) and skewer it on a needle.

2. Then add a set volume of water to a boiling tube on a clamp,

3. measure the temp of the water.

4. Set fire to the food

5. immediately hold it under the boiling tube,

6. repeat until it no longer burns.

7. measure the water temp again.

What is the calculation for energy in food?

energy released from food per gram:Mass of water x temp change in water x 4.2 / mass of food sample (g). To work out how many joules are in each gram of food: Energy in food / mass of food

What are the issues with the calorimetry experiment?

• Distance between food and water may change

• Fatty foods may drip meaning energy isn't measured

• Heat may go into the air not heat the water

What is it used for?

Calorimeters are often used in the food industry to measure the energy in food. This value is given in joules or calories in the nutritional information panel on the food packaging.