calorimetre

A calorimeter is a device used to measure the heat of chemical reactions or physical changes. It operates on the principle of calorimetry, which involves the transfer of heat from a reaction or change to a known mass of a substance with a known specific heat capacity, typically water. By measuring the temperature change of this substance, the amount of heat absorbed or released can be calculated.

There are several types of calorimeters, but common designs include the bomb calorimeter and the coffee-cup calorimeter. A bomb calorimeter is used for reactions that produce gases, often involving combustion. It is a sealed, rigid container where the reaction occurs, and the heat released increases the temperature of the surrounding water. A coffee-cup calorimeter, often used in educational settings, is simpler and consists of an insulated container, typically a Styrofoam cup, holding water. Reactants are added to the water, and the temperature change is monitored.

Calorimetry is a fundamental technique in thermochemistry, a branch of physical chemistry. It is employed in various scientific and industrial applications, including determining the energy content of foods, studying the thermodynamics of chemical reactions, and measuring the heat of combustion of fuels. The accuracy of a calorimeter depends on its insulation and the precision of its temperature measurement.