1. What is an Energy to Evaporate Water Calculator?

Definition: This calculator estimates the energy required to completely evaporate a given mass of water.

Purpose: It helps engineers, scientists, and students determine the thermal energy needed for phase change from liquid to vapor.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( E \) — Energy required (Joules)
• \( m \) — Mass of water (kilograms)
• \( h_{fg} \) — Enthalpy of vaporization (Joules/kilogram)

Explanation: The mass of water is multiplied by the specific energy needed to change phase from liquid to vapor at constant temperature.

3. Importance of Energy Calculation

Details: Accurate energy calculation is crucial for designing heating systems, boilers, distillation processes, and understanding thermodynamic cycles.

4. Using the Calculator

Tips: Enter the mass of water in kilograms and the enthalpy of vaporization (default 2,260,000 J/kg for water at 100°C). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is enthalpy of vaporization?
A: It's the energy required to change 1 kg of liquid to vapor at constant temperature and pressure.

Q2: Why is the default value 2,260,000 J/kg?
A: This is the standard value for water at 100°C (boiling point at 1 atm pressure).

Q3: Does this include energy to heat water to boiling?
A: No, this only calculates the phase change energy. Heating energy must be calculated separately.

Q4: How does pressure affect the calculation?
A: Higher pressures increase boiling point and decrease h_fg. Use appropriate h_fg for your pressure.

Q5: Can this be used for other liquids?
A: Yes, but you must use the correct h_fg value for the specific liquid.