1. What is Enthalpy Change?

The change in enthalpy (ΔH) represents the heat content change of a system at constant pressure. It's a fundamental concept in thermodynamics used to quantify energy changes during chemical reactions and physical processes.

2. How Does the Calculator Work?

The calculator uses the enthalpy change equation:

Where:

• \( \Delta H \) — Change in enthalpy (Joules)
• \( m \) — Mass of the substance (kg)
• \( c \) — Specific heat capacity (J/kg·K)
• \( \Delta T \) — Temperature change (Kelvin)

Explanation: The equation calculates the energy required to change the temperature of a given mass of substance, considering its specific heat capacity.

3. Importance of Enthalpy Calculation

Details: Enthalpy change calculations are essential in chemical engineering, thermodynamics, and process design to determine energy requirements for heating/cooling processes.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between enthalpy and heat?
A: Enthalpy includes both internal energy and PV work, while heat refers specifically to energy transfer due to temperature difference.

Q2: Can I use this for phase changes?
A: No, this equation is only for temperature changes without phase transition. For phase changes, you need latent heat.

Q3: Why use Kelvin for temperature change?
A: Kelvin is used because it's an absolute scale where 0 represents absolute zero, making calculations more accurate.

Q4: What are typical specific heat values?
A: Water: ~4186 J/kg·K, Aluminum: ~900 J/kg·K, Iron: ~450 J/kg·K. Values vary with temperature.

Q5: How does pressure affect this calculation?
A: This simple equation assumes constant pressure. For precise work at varying pressures, more complex equations are needed.