Thermal Flashcards
Probability of a state

Partition β
β = 1 / (kT)
Partition function

Expectation value of energy (full formula)

Expectation value of energy (partition shortcut)

Entropy in terms of multiplicity
S = k lnΩ
Entropy, given probability of microstates

Shortcut entropy expression for monotomic ideal gas

Classical limit of the partition function

Binomial coefficient

Sterling’s formula

1st law of thermal
ΔU = Q - W
2nd law of thermal

Work in a reversible process
δW = P dV
Differential form of entropy change of a system undergoing a reversible process
δQ = T dS
Integral form of entropy change of a system undergoing a reversible process

Fundamental thermodynamic identity
dU = TdS - PdV
Temperature given by the fundamental thermodynamic identity

Pressure given the fundamental thermodynamic identity

Energy Maxwell relation

Heat capacity at constant volume

Heat capacity at constant pressure

Differentiation of the fundamental thermodynamic identity with respect to T

Difference of heat capacities of an ideal gas
CP - CV = Nk
Change in temperature
Q = mcΔT
Heat engine efficiency

Maximum efficiency of a heat engine

Internal energy of a classical ideal gas

vrms

Speed of sound in an ideal gas, given pressure and density

Speed of sound in an ideal gas, given temperature and mass

Fermi-Dirac distribution

Bose-Einstein distrubtion

Average number of fermions/bosons

Approximation of average number of fermions/bosons if energy levels are spaced closely together

γ
(f+2) / f
Monotomic molecule degrees of freedom
3 translational, f=3
Diatomic molecule degrees of freedom
3 translational, 2 rotational, 2 vibrational, f = 5 +2b
b=0 at room temperature
b=1 at high temperatures
Polyatomic molecule degrees of freedom
3 translational, 3 rotational, 2N vibrational, f=6+2N
N=number of atoms
Solid degrees of freedom
3 vibrational in each kinetic and potential energy
f=6