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23 sie 2019 · A calorimeter is a device that you can use to measure the energy of food. You put a small amount of the food in a calorimeter. Then you submerge the calorimeter in a known quantity of water.
Let's investigate the basis for these caloric values in terms of the chemical reactions that provide the energy. Energy changes which accompany chemical reactions are almost always expressed by thermochemical equations. The combustion of stearic acid, which is the main component of saturated fats, is written:
Learning Objectives. By the end of this section, you will be able to: Explain the human body’s consumption of energy when at rest vs. when engaged in activities that do useful work. Calculate the conversion of chemical energy in food into useful work.
The chemical energy in food is converted into thermal energy through metabolism; light energy is converted into chemical energy through photosynthesis. In a larger example, the chemical energy contained in coal is converted into thermal energy as it burns to turn water into steam in a boiler.
The first law of thermodynamics applies the conservation of energy principle to systems where heat and work are the methods of transferring energy into and out of the systems. It can also be used to describe how energy transferred by heat is converted and transferred again by work.
10 lip 2024 · Try this class experiment to investigate how much energy different foods contain. In this practical, students burn a sample of a foodstuff of known mass, heating a known volume of water. From the measured temperature change, students calculate the energy transferred to the water, and hence estimate the energy present per unit mass of food.
Energy is often measured in calories (kcal), but the scientific units are joules (J) or kilojoules (kJ). The food we consume provides us with the energy that enables our body to function. The amount of energy in different foods can be found on their outer packaging, on food labels.
