Thermodynamics
Boltzmann Entropy
Statistical definition of entropy.
Variables
SJ/K
Entropy
Statistical entropy
In SI units: kg·m²/(s²·K)
kBJ/K
Boltzmann constant
1.38×10⁻²³
In SI units: kg·m²/(s²·K)
Wunitless
Number of microstates
Multiplicity
Derivation
Fundamental relation connecting microscopic and macroscopic.
Your notes
0/5000
Constants in this formula
Other thermodynamics formulas with the same quantities
- Gibbs Free Energy (Entropy) shares Entropy
- Helmholtz Free Energy (Entropy) shares Entropy
- Ideal Gas Law (Molecular) (Kinetic Theory) shares Boltzmann constant
- Average Kinetic Energy (Gas) (Kinetic Theory) shares Boltzmann constant
- Root Mean Square Speed (Kinetic Theory) shares Boltzmann constant
- Mean Free Path (Kinetic Theory) shares Boltzmann constant
Where this formula is listed
- Thermodynamics formulas, under Entropy, alongside Entropy Change (Ideal Gas).
- In the thermodynamics list it comes after Entropy Change (Ideal Gas) and before Gibbs Free Energy.
- Thermodynamics formula sheet, one of 34 formulas printed with symbol keys and SI units.
- The full formula index, grouped by category and topic.
Common questions
What is the Boltzmann Entropy formula?
Boltzmann Entropy is written S = k_B ln W. Statistical definition of entropy. It belongs to Thermodynamics, under Entropy.
What are the units in S = k_B ln W?
In SI units, S is entropy, measured in kg·m²/(s²·K); k_B is boltzmann constant, measured in kg·m²/(s²·K); W is number of microstates (dimensionless).
How is the Boltzmann Entropy formula derived?
Fundamental relation connecting microscopic and macroscopic. The result is S = k_B ln W.