Molar Heat Capacity Formula:
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Molar heat capacity (Cm) is the amount of heat required to raise the temperature of 1 mole of a substance by 1 Kelvin. It's an intensive property that characterizes how a substance responds to heat input at the molecular level.
The calculator uses the molar heat capacity formula:
Where:
Explanation: The formula divides the total heat capacity (extensive property) by the number of moles to get the molar heat capacity (intensive property).
Details: Molar heat capacity is crucial in thermodynamics for calculating heat transfer, designing thermal systems, and understanding molecular properties. It varies with temperature and phase of the substance.
Tips: Enter heat capacity in Joules per Kelvin (J/K) and amount of substance in moles. Both values must be positive numbers.
Q1: What's the difference between heat capacity and molar heat capacity?
A: Heat capacity (C) depends on the amount of substance, while molar heat capacity (Cm) is normalized per mole, making it an intensive property.
Q2: What are typical values for molar heat capacity?
A: For most solids at room temperature, molar heat capacity is about 25 J/(mol·K) (Dulong-Petit law). For ideal gases, it's about 20.8 J/(mol·K) for monatomic gases.
Q3: How does molar heat capacity vary with temperature?
A: Generally increases with temperature, especially near phase transitions. At very low temperatures, it follows the Debye T³ law.
Q4: What's the difference between Cp and Cv?
A: Cp is molar heat capacity at constant pressure, while Cv is at constant volume. For solids, they're nearly equal, but for gases, Cp > Cv.
Q5: How is this related to specific heat capacity?
A: Specific heat capacity is per unit mass (J/(g·K)), while molar heat capacity is per mole (J/(mol·K)). They're related through the molar mass of the substance.