ZIMSEC O Level Combined Science Notes: Experiment: Food and Energy
Aim: Comparing the energy value of foods
Materials: burners, small containers/beakers to hold the water, food holders, thermometers, different types of starchy and fatty foods
- Set up the apparatus as shown above
- Measure the temperature of the water before heating
- Heat a small piece of food in a burner flame until it ignites and burns on its own. Hold the burning food holder using tongs under the container/beaker of water.
- Stir the water continuously using the thermometer.
- Allow the food to burn until the flame dies out.
- Measure the temperature of the water and calculate the change in temperature
- Repeat the process using different types of food
Results and Observations
- Both carbohydrates and fats contain a lot of energy
- When the food is heated and reaches a certain temperature it burns on its own
- While it is burning it releases energy which is used to heat the water
- To compare the energy of different foods the same amount of food is burnt and the same amount of water is heated
NB 1) Safety goggles should be worn in this experiment to prevent eye injury
2) Also for safety reasons burning tubes/food holders should be pointed away from people as foods burn real well
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