Dulong-Petit Law (C = 3R)
jee-mainjee-advanced
C = 3R
What each symbol means
| Symbol | What it stands for |
|---|---|
| C | Molar specific heat capacity of solid (J mol⁻¹ K⁻¹) |
| R | Universal gas constant = 8.314 J mol⁻¹ K⁻¹ |
When to use this
Valid for most solids at ordinary temperatures (T >> θ_D, the Debye temperature). Breaks down at low temperatures where quantum effects dominate (C → 0 as T → 0, consistent with third law). Per mole of atoms; for compounds like NaCl, use 3R per atom. Based on equipartition theorem with 3D oscillators (6 DOF).