Clausius–Clapeyron relation

E303520

physical law thermodynamic relation

The Clausius–Clapeyron relation is a fundamental thermodynamic equation that describes how the pressure and temperature of a phase transition, such as boiling or condensation, are related.

Try in SPARQL Jump to: Surface forms Disambiguation Statements Elicitation Referenced by

All labels observed (2)

Label	Occurrences
Clapeyron equation	2
Clausius–Clapeyron relation canonical	1

How this entity was disambiguated

This entity first appeared as the object of triple T2842730 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.

NED1 Entity disambiguation (via context triple) gpt-5-mini-2025-08-07

Target entity: Clausius–Clapeyron relation
Context triple: [Rudolf Clausius, notableFor, Clausius–Clapeyron relation]

A. Dulong–Petit law
The Dulong–Petit law is an early empirical rule in thermodynamics stating that many solid elements have approximately the same molar heat capacity at high temperatures.
B. Sackur–Tetrode equation
The Sackur–Tetrode equation is a fundamental formula in statistical mechanics that gives the absolute entropy of an ideal monatomic gas in terms of its volume, temperature, and particle number.
C. Lorentz–Lorenz equation
The Lorentz–Lorenz equation is a fundamental relation in optics and electromagnetism that connects a material’s refractive index to its molecular polarizability and density.
D. Saha ionization equation
The Saha ionization equation is a fundamental formula in astrophysics and plasma physics that relates the ionization state of a gas in thermal equilibrium to its temperature and pressure, crucial for understanding stellar atmospheres and spectra.
E. Goodman–Martínez–Thompson correlation
The Goodman–Martínez–Thompson correlation is the most widely accepted scholarly conversion formula that aligns dates in the ancient Maya Long Count calendar with the Gregorian calendar.
F. None of above. chosen
G. Unsure - the case is ambiguous/there is not enough information to decide.

NED2 Entity disambiguation (via description) gpt-5-mini-2025-08-07

Target entity: Clausius–Clapeyron relation
Target entity description: The Clausius–Clapeyron relation is a fundamental thermodynamic equation that describes how the pressure and temperature of a phase transition, such as boiling or condensation, are related.

A. Dulong–Petit law
The Dulong–Petit law is an early empirical rule in thermodynamics stating that many solid elements have approximately the same molar heat capacity at high temperatures.
B. Sackur–Tetrode equation
The Sackur–Tetrode equation is a fundamental formula in statistical mechanics that gives the absolute entropy of an ideal monatomic gas in terms of its volume, temperature, and particle number.
C. Lorentz–Lorenz equation
The Lorentz–Lorenz equation is a fundamental relation in optics and electromagnetism that connects a material’s refractive index to its molecular polarizability and density.
D. Saha ionization equation
The Saha ionization equation is a fundamental formula in astrophysics and plasma physics that relates the ionization state of a gas in thermal equilibrium to its temperature and pressure, crucial for understanding stellar atmospheres and spectra.
E. Goodman–Martínez–Thompson correlation
The Goodman–Martínez–Thompson correlation is the most widely accepted scholarly conversion formula that aligns dates in the ancient Maya Long Count calendar with the Gregorian calendar.
F. None of above. chosen

Statements (48)

Predicate	Object
instanceOf	physical law ⓘ thermodynamic relation ⓘ
appliesTo	liquid–vapor equilibrium ⓘ phase transitions ⓘ solid–liquid equilibrium ⓘ solid–vapor equilibrium ⓘ
approximateForm	ln(P) = −L∕(R·T) + constant ⓘ
assumes	thermodynamic equilibrium between phases ⓘ
category	equation of state relations ⓘ phase equilibrium equations ⓘ
derivedFrom	Gibbs free energy equality of coexisting phases ⓘ first law of thermodynamics ⓘ second law of thermodynamics ⓘ
describes	dependence of phase equilibrium pressure on temperature ⓘ
domain	equilibrium thermodynamics ⓘ
expresses	slope of coexistence curve in P–T diagram ⓘ
field	thermodynamics ⓘ
hasUnitContext	SI units ⓘ
hasVariable	latent heat L ⓘ pressure P ⓘ specific volume v ⓘ temperature T ⓘ
historicalPeriod	19th century ⓘ
implies	approximately 6–7 percent increase in saturation vapor pressure per kelvin near Earth surface temperatures ⓘ
language	mathematical physics notation ⓘ
mathematicalForm	dP/dT = L / (T · Δv) ⓘ
namedAfter	Émile Clapeyron ⓘ surface form: Benoît Paul Émile Clapeyron Rudolf Clausius ⓘ
relatedTo	Gibbs–Duhem equation ⓘ Maxwell relations ⓘ vapor pressure curve ⓘ
relatesQuantity	latent heat ⓘ pressure ⓘ specific volume change ⓘ temperature ⓘ
usedFor	calculating saturation vapor pressure ⓘ climate science humidity scaling ⓘ cloud physics modeling ⓘ engineering thermodynamics calculations ⓘ estimating boiling point at different pressures ⓘ estimating condensation conditions ⓘ meteorology ⓘ
usedIn	boiler and condenser design ⓘ climate change precipitation projections ⓘ refrigeration cycle analysis ⓘ weather prediction models ⓘ
validWhen	latent heat is approximately constant over temperature range ⓘ vapor behaves approximately as ideal gas ⓘ

How these facts were elicited

Referenced by (3)

Full triples — surface form annotated when it differs from this entity's canonical label.

Rudolf Clausius → notableFor → Clausius–Clapeyron relation ⓘ

Émile Clapeyron → notableWork → Clausius–Clapeyron relation ⓘ

this entity surface form: Clapeyron equation

Émile Clapeyron → notableConcept → Clausius–Clapeyron relation ⓘ