Enthalpy differential¶

The fundamental thermodynamic relations are fundamental equations which demonstate how the important thermodynamic quantities depend on variables that are measurable experimentally.

Notation:

\(d\) denotes an exact, path-independent differential.

Notes:

Entropy, pressure, and particle count are so called natural variables of enthalpy as a thermodynamic potential.
For a system with more than one type of particles, the last term can be represented as a sum over all types of particles, i.e. \(\sum_i \mu_i \, d N_i\).

Conditions:

The system is in thermal equilibrium with its surroundings.
The system is composed of only one type of particles, i.e. the system is a pure substance.

Links:

Wikipedia.

enthalpy_change¶: Infinitesimal change in enthalpy of the system.

Symbol:: dH
Latex:: \(dH\)
Dimension:: energy

temperature¶: temperature of the system.

Symbol:: T
Latex:: \(T\)
Dimension:: temperature

entropy_change¶: Infinitesimal change in entropy of the system.

Symbol:: dS
Latex:: \(dS\)
Dimension:: energy/temperature

volume¶: volume of the system.

Symbol:: V
Latex:: \(V\)
Dimension:: volume

pressure_change¶: Infinitesimal change in pressure inside the system.

Symbol:: dp
Latex:: \(dp\)
Dimension:: pressure

chemical_potential¶: chemical_potential of the system.

Symbol:: mu
Latex:: \(\mu\)
Dimension:: energy

particle_count_change¶: Infinitesimal change in the particle_count of the system.

Symbol:: dN
Latex:: \(dN\)
Dimension:: dimensionless

law¶

dH = T * dS + V * dp + mu * dN

Latex:: \[dH = T dS + V dp + \mu dN\]