Boltzmann's constant is closely related to the ideal gas constant in that both are useful for the ideal gas law in determining the relationship among pressure, volume, and the number of molecules of gas and the temperature. ...

Where do we use Boltzmann constant?

In classical statistical mechanics, Boltzmann Constant is used to expressing the equipartition of the energy of an atom. It is used to express the Boltzmann factor. It plays a major role in the statistical definition of entropy. In semiconductor physics, it is used to express thermal voltage.

What is the difference between universal gas constant and Boltzmann constant?

The Boltzmann constant (kB) is for one molecule (or atom); the universal gas constant (R) is for one mole of molecules (or atoms).