1. What is the Antoine Equation?

The Antoine equation is a simple 3-parameter fit to experimental vapor pressure data. It relates the vapor pressure of a substance to its temperature and is widely used in chemical engineering and thermodynamics.

2. How Does the Calculator Work?

The calculator uses the Antoine equation:

Where:

• \( P \) — Vapor pressure (Pa)
• \( A \) — Antoine constant (dimensionless)
• \( B \) — Antoine constant (K)
• \( C \) — Antoine constant (K)
• \( T \) — Temperature (K)

Explanation: The equation describes the nonlinear relationship between temperature and vapor pressure for pure substances.

3. Importance of Pressure Calculation

Details: Accurate vapor pressure estimation is crucial for process design, safety calculations, and predicting phase behavior in chemical systems.

4. Using the Calculator

Tips: Enter the Antoine constants (A, B, C) for your specific substance and the temperature in Kelvin. Temperature must be greater than absolute zero.

5. Frequently Asked Questions (FAQ)

Q1: Where can I find Antoine constants for different substances?
A: Antoine constants are available in chemical engineering handbooks and thermodynamic databases for many common substances.

Q2: What is the temperature range for this equation?
A: The equation is typically valid over the temperature range for which the constants were fitted, usually several tens of degrees.

Q3: Can I use this for mixtures?
A: No, the Antoine equation is for pure substances only. For mixtures, more complex models are needed.

Q4: What are typical units for Antoine constants?
A: A is dimensionless, B is typically in Kelvin, and C is typically in Kelvin, but always check your source as different forms exist.

Q5: How accurate is this equation?
A: Within its valid temperature range, it typically provides vapor pressure values accurate to within a few percent.