Molar Heat Capacity at Constant Pressure (Cp = (ΔQ/ΔT)p = (ΔU/ΔT) + P(ΔV/ΔT)p)
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Cp = (ΔQ/ΔT)p = (ΔU/ΔT) + P(ΔV/ΔT)p
What each symbol means
| Symbol | What it stands for |
|---|---|
| P | Constant pressure (Pa) |
| Cp | Molar heat capacity at constant pressure (J mol⁻¹ K⁻¹) |
| ΔQ | Heat supplied at constant pressure (J) |
| ΔT | Temperature change (K) |
| ΔU | Change in internal energy (J) |
| ΔV | Volume change (m³) |
When to use this
Per mole of ideal gas at constant pressure. For n moles: Q = nCpΔT. Part of heat increases internal energy (ΔU = nCvΔT), part does expansion work (W = nRΔT). Connects to Cv via Mayer's relation: Cp = Cv + R.