What Is Heat Capacity?

The standard definition of heat capacity is: "When a system increases its temperature by dT due to the addition of a small amount of heat dQ, the amount of dQ / dT is the heat capacity of the system." (GB3102.4-93), usually based on The symbol C indicates that the unit is J / K.

Without phase change and

The amount of heat that an object absorbs (or releases) from the outside every time the object temperature rises (or decreases) in a certain process. For example, when the heat transferred is Q and the temperature changes T, the heat capacity C of the object in the process is defined as

Heat capacity is a function of temperature, and heat capacity values vary with different temperature ranges. Many scientists have used experimental methods to accurately determine the heat capacity values of various substances at various temperatures, and have obtained empirical expressions that show the relationship between heat capacity and temperature. The commonly used empirical formula has the following two forms.

C _{p , m} = a + bT + cT ²

C _{p , m} = a + bT + cT ^-2

In the formula: a, b, c, and c are all empirical constants, which vary with different substances and different temperature ranges. For the constant values in the empirical formulas for the heat capacity of each substance, please refer to the appendix, or refer to the relevant reference books and manuals.