Kilocalorie

Definition

A kilocalorie (kcal) is a unit of energy commonly used in the field of thermodynamics. It is defined as the amount of heat required to raise the temperature of one kilogram of water by one degree Celsius.

5 Must Know Facts For Your Next Test

1. 1 kilocalorie is equivalent to 4184 joules in SI units.
2. Kilocalories are often used interchangeably with Calories in nutritional contexts; however, in physics, precision is crucial.
3. The specific heat capacity of water is approximately 1 kcal/kg•°C, making it a useful standard for calorimetry experiments.
4. Heat transfer calculations frequently involve converting between joules and kilocalories to solve problems involving energy exchange.
5. In calorimetry, kilocalories can be used to calculate the energy changes during phase transitions or chemical reactions.

Review Questions

• What is the SI unit equivalent of one kilocalorie?
• How many degrees Celsius does one kilocalorie raise the temperature of one kilogram of water?
• Why might a physicist prefer to use joules over kilocalories in precise measurements?

Related terms

Joule:

A joule (J) is the SI unit of energy. It is defined as the energy transferred when one newton of force moves an object one meter.

Specific Heat:

\\text{Specific heat} refers to the amount of heat per unit mass required to raise the temperature by one degree Celsius.

Calorimetry:

\\text{Calorimetry} is the science or act of measuring changes in state variables of a body for deriving the heat transfer associated with changes due to chemical reactions, physical changes, or phase transitions.