What is the amount of heat necessary to raise the temperature of 1g of water by 1 degree Celsius called?

The amount of heat necessary to raise the temperature of 1 gram of water by 1 degree Celsius is known as a calorie. This unit specifically refers to the energy required to change the temperature of water, which is significant in chemistry and thermodynamics, particularly when discussing calorie-based measurements of energy in food and metabolism.

The calorie is calibrated based on the specific heat capacity of water, making it a fundamental unit in understanding thermal energy exchange. One calorie is equal to approximately 4.184 joules, linking it to the broader metric system. When working with water, using calories helps simplify calculations involving heat transfer, especially in biochemical applications where water acts as a solvent and medium for reactions.

In contrast, other terms mentioned, such as joules and BTUs (British Thermal Units), represent different scales or applications of energy measurement. Kelvin is a unit of temperature rather than heat energy. Thus, focusing on the calorie is crucial for accurate discussions of thermal properties in water and similar contexts.