1. What is Vapor Pressure of Water?

Definition: Vapor pressure is the pressure exerted by water vapor in thermodynamic equilibrium with its condensed phases at a given temperature.

Purpose: Understanding vapor pressure is crucial in meteorology, HVAC design, chemical engineering, and various industrial processes.

2. How Does the Calculator Work?

The calculator uses the Tetens equation:

Where:

• \( P \) — Vapor pressure (hPa)
• \( T \) — Temperature (°C)
• \( \exp \) — Exponential function

Explanation: The equation relates the vapor pressure of water to temperature, showing how vapor pressure increases exponentially with temperature.

3. Importance of Vapor Pressure Calculation

Details: Accurate vapor pressure calculations are essential for weather forecasting, humidity control, distillation processes, and understanding evaporation rates.

4. Using the Calculator

Tips: Simply enter the temperature in Celsius. The calculator will compute the vapor pressure in hectopascals (hPa).

5. Frequently Asked Questions (FAQ)

Q1: What is the range of validity for the Tetens equation?
A: The Tetens equation provides good estimates for temperatures between 0°C and 100°C.

Q2: Why is vapor pressure important in meteorology?
A: It helps determine humidity levels and is fundamental to understanding cloud formation and precipitation.

Q3: How does altitude affect vapor pressure?
A: While the equation gives the same result, the boiling point changes with atmospheric pressure at different altitudes.

Q4: What's the relationship between vapor pressure and boiling point?
A: The boiling point occurs when vapor pressure equals atmospheric pressure.

Q5: Are there more accurate equations than Tetens?
A: Yes, the Antoine equation is more accurate but more complex, with different coefficients for different temperature ranges.