Dulong–Petit law for molar heat capacity of many solids at high temperature
E287399
The Dulong–Petit law states that many crystalline solids have an approximately constant molar heat capacity of about 3R at sufficiently high temperatures, reflecting classical equipartition of energy among atomic vibrations.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Dulong–Petit law for molar heat capacity of many solids at high temperature canonical | 1 |
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
empirical law
ⓘ
law of solid-state physics ⓘ thermodynamic law ⓘ |
| appliesTo |
many crystalline solids
ⓘ
monatomic crystalline solids ⓘ |
| approachedAsLimit |
high-temperature limit of the Debye model
ⓘ
high-temperature limit of the Einstein model ⓘ |
| assumes |
classical behavior of atomic vibrations
ⓘ
each atom in a solid has three translational degrees of freedom ⓘ each vibrational degree of freedom contributes kB to energy per atom ⓘ harmonic approximation for atomic vibrations ⓘ |
| basedOn |
equipartition theorem
ⓘ
surface form:
classical equipartition theorem
|
| concerns |
heat capacity of solids
ⓘ
lattice vibrations ⓘ |
| explains | approximate constancy of molar heat capacity of many solids at high temperature ⓘ |
| failsAt | low temperatures ⓘ |
| field |
solid-state physics
ⓘ
statistical mechanics ⓘ thermodynamics ⓘ |
| historicalContext | formulated in the early 19th century ⓘ |
| holdsBestFor |
heavy metallic elements
ⓘ
simple monatomic metals ⓘ |
| impliesPerAtomHeatCapacity | 3kB ⓘ |
| involvesConstant |
Boltzmann constant
ⓘ
surface form:
Boltzmann constant kB
universal gas constant R ⓘ |
| isClassicalApproximationOf | quantum theory of lattice vibrations ⓘ |
| limitationsInclude |
deviations for covalent crystals like diamond
ⓘ
deviations for light-element solids ⓘ deviations for solids with low Debye temperature ⓘ |
| mathematicalForm | Cv,m ≈ 3R ⓘ |
| molarHeatCapacityApproximateNumericalValue |
24.9 J mol−1 K−1
ⓘ
25 J mol−1 K−1 ⓘ |
| molarHeatCapacityValue | 3R ⓘ |
| namedAfter |
Alexis Thérèse Petit
ⓘ
Pierre Louis Dulong ⓘ |
| predicts | constant molar heat capacity for many solids at high temperature ⓘ |
| relatedConcept |
Debye model
ⓘ
surface form:
Debye model of solids
Debye model ⓘ
surface form:
Einstein model of solids
|
| relatesQuantity |
gas constant R
ⓘ
molar heat capacity at constant volume ⓘ |
| states | the molar heat capacity at constant volume is approximately 3R ⓘ |
| temperatureRegime | high temperature ⓘ |
| usedFor | estimating atomic weights of elements historically ⓘ |
| usedIn |
introductory solid-state physics
ⓘ
introductory thermodynamics education ⓘ |
| validWhen | thermal energy kBT is large compared to vibrational quantum energies ⓘ |
| yearProposed | 1819 ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.
equipartition theorem
→
implies
→
Dulong–Petit law for molar heat capacity of many solids at high temperature
ⓘ