Thermodynamic vs Molecular Approach [ENDORSED]

[Abigail Volk 1F]

When using the Boltzmann's equation, there is a thermodynamic approach and a molecular approach, whats the difference between the two? When would you know to use which one?

[Chem_Mod]

Please provide more information especially about what you mean by "thermodynamic vs molecular approach". The following is the explanation to what I think you are asking.

The Boltzmann equation for entropy is S = k_BlnW.

In order to determine the microstates W, we consider small systems usually of just a few objects or molecules.

When the system becomes macroscopic, we can no longer enumerate every single microstate available and so we use a thermodynamic approach and S = dq/T.