Change In Enthalpy Calculator

Enthalpy Change Equation:

\[ \Delta H = m \times C_p \times \Delta T \]

Enthalpy Change (ΔH):

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1. What is Enthalpy Change?

Enthalpy change (ΔH) is a thermodynamic quantity that represents the heat absorbed or released during a chemical reaction or physical process at constant pressure. It's a fundamental concept in thermodynamics and chemistry.

2. How Does the Calculator Work?

The calculator uses the enthalpy change equation:

\[ \Delta H = m \times C_p \times \Delta T \]

Where:

\( \Delta H \) — Enthalpy change (Joules)
\( m \) — Mass of the substance (kg)
\( C_p \) — Specific heat capacity (J/kg·K)
\( \Delta T \) — Temperature change (K)

Explanation: The equation calculates the heat energy required to change the temperature of a given mass of substance by a certain amount.

3. Importance of Enthalpy Change Calculation

Details: Enthalpy change calculations are crucial for understanding energy transfers in chemical reactions, designing heating and cooling systems, and analyzing thermodynamic processes in engineering applications.

4. Using the Calculator

Tips: Enter mass in kilograms, specific heat capacity in J/kg·K, and temperature change in Kelvin. All values must be valid (mass > 0, specific heat > 0).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between enthalpy and internal energy?
A: Enthalpy (H) includes both internal energy and the product of pressure and volume (H = U + PV), making it more useful for constant-pressure processes.

Q2: Can this calculator be used for phase changes?
A: No, this equation is for temperature changes only. Phase changes require latent heat calculations (ΔH = m × L).

Q3: Why use Kelvin instead of Celsius for temperature change?
A: While the magnitude of temperature change is the same in both scales, Kelvin is the SI unit for thermodynamic calculations and ensures dimensional consistency.

Q4: What are typical specific heat capacity values?
A: Water: 4184 J/kg·K, Aluminum: 897 J/kg·K, Iron: 449 J/kg·K. Values vary significantly between materials.

Q5: How does this relate to chemical reactions?
A: For chemical reactions, enthalpy change is typically measured per mole of reaction and includes both temperature changes and phase changes.