Calorimetry

Definition

Calorimetry is the measurement of heat transfer in chemical reactions or physical changes. It is used to determine the enthalpy changes of reactions.

5 Must Know Facts For Your Next Test

1. Calorimetry involves the use of a calorimeter, which can be either a constant-pressure calorimeter or a bomb calorimeter.
2. The heat absorbed or released in a reaction can be calculated using the formula $q = mc\Delta T$ where $q$ is heat, $m$ is mass, $c$ is specific heat capacity, and $\Delta T$ is the change in temperature.
3. In an exothermic reaction, heat is released and the temperature of the surroundings increases; in an endothermic reaction, heat is absorbed and the temperature decreases.
4. A bomb calorimeter is typically used for combustion reactions and operates at constant volume.
5. The principle of conservation of energy underlies calorimetry: energy lost by one substance must be gained by another.

Review Questions

• What are the two main types of calorimeters used in measuring heat transfer?
• How do you calculate the amount of heat transferred using specific heat capacity?
• What distinguishes an exothermic reaction from an endothermic reaction in terms of heat transfer?

Related terms

Enthalpy:

A thermodynamic quantity equivalent to the total heat content of a system. It is equal to internal energy plus the product of pressure and volume.

Specific Heat Capacity:

The amount of heat required to raise the temperature of one gram of a substance by one degree Celsius.

Bomb Calorimeter:

A device used to measure the energy released during a combustion reaction at constant volume.