Heat capacity
Physical size  

Surname  Heat capacity  
Formula symbol  

The heat capacity of a body is the ratio of the heat supplied to it ( ) to the resulting temperature increase ( ):
The unit of heat capacity is J / K .
In the case of homogeneous bodies, the heat capacity can be calculated as the product of the specific heat capacity and the mass of the body,
or as a product of its molar heat capacity and its amount of substance :
Both the specific and the molar heat capacity are material constants and are tabulated in relevant reference works.
The heat capacity is an extensive state variable , so it can be calculated for a body that is composed of parts as the sum of the respective heat capacities of its parts. The following therefore results for the total heat capacity :
For layer systems such as B. wall constructions , the heat capacity per unit area is given in J / (m ^{2} · K), for yard goods such as. B. extruded heat sinks per unit length , in J / (m · K).
Determination of the heat capacity in the mixing test
The experimental determination of the heat capacity of a body shows how to deal with this quantity:
The body is first placed in boiling water ( ) until it has reached this temperature itself. Then you transfer it to a calorimeter in which there is water at the temperature of . A mixing temperature of .
So the water has warmed up.
With the known specific heat capacity of water ( ), the heat absorbed by the water is calculated
 .
The body has given off this amount of heat to the water when it cools down , so it is . Hence the heat capacity of the body is: