1. What is Specific Latent Heat of Evaporation?

Definition: The Specific Latent Heat is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process.

Purpose: This calculator helps determine the latent heat of evaporation for water near standard temperature and pressure conditions.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( L \) — Specific Latent Heat (J/kg)
• \( \frac{de}{dT}_{slope} \) — Slope of Co-existence Curve of Water Vapor (Pa/K)
• \( [R] \) — Universal gas constant (8.314 J/mol·K)
• \( T \) — Temperature (K)
• \( e_S \) — Saturation Vapor Pressure (Pa)

Explanation: The formula relates the slope of the vapor pressure curve to the latent heat of vaporization.

3. Importance of Latent Heat Calculation

Details: Understanding latent heat is crucial for thermodynamics, meteorology, and engineering applications involving phase changes.

4. Using the Calculator

Tips: Enter the slope of the coexistence curve (typically around 50 Pa/K for water near STP), temperature in Kelvin, and saturation vapor pressure in Pascals.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical value for the slope of the coexistence curve?
A: For water near standard conditions, it's approximately 50 Pa/K, but varies with temperature.

Q2: Why is temperature squared in the formula?
A: The squared term comes from the Clausius-Clapeyron relation which this formula is derived from.

Q3: How accurate is this calculation?
A: It provides good estimates near standard conditions but becomes less accurate at extreme temperatures.

Q4: Where can I find saturation vapor pressure values?
A: Use thermodynamic tables or the Antoine equation to calculate saturation vapor pressure.

Q5: What are common applications of this calculation?
A: Used in designing heat exchangers, understanding atmospheric processes, and energy calculations in phase-change systems.