1. What is Delta H Fusion?

Delta H Fusion (enthalpy of fusion) is the amount of energy required to change a substance from solid to liquid phase at constant temperature and pressure. It's a fundamental thermodynamic property measured in joules per gram (J/g).

2. How Does the Calculator Work?

The calculator uses the Delta H Fusion equation:

Where:

• \( Energy \) — Thermal energy absorbed during phase change (J)
• \( Mass \) — Mass of the substance undergoing phase change (g)

Explanation: The equation calculates the energy required per unit mass to melt a solid without changing its temperature.

3. Importance of Delta H Fusion Calculation

Details: Knowing the enthalpy of fusion is crucial for materials science, chemical engineering, and understanding phase change behavior in substances.

4. Using the Calculator

Tips: Enter energy in joules (J) and mass in grams (g). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical ΔH fusion values?
A: Water: 334 J/g, Iron: 247 J/g, Aluminum: 397 J/g. Values vary significantly between substances.

Q2: How is this different from heat capacity?
A: ΔH fusion is for phase change at constant temperature, while heat capacity relates to temperature change.

Q3: Why measure in J/g rather than kJ/mol?
A: J/g is more practical for experimental measurements where mass is easier to determine than moles.

Q4: Does pressure affect ΔH fusion?
A: Yes, but the effect is small for moderate pressure changes. The value is usually reported at 1 atm.

Q5: Can this be used for freezing?
A: Yes, the magnitude is the same but the sign is negative (energy released during freezing).