Vapor Pressure Calculator

Vapor Pressure Formula (Raoult's Law for mixtures):

\[ P = \sum P_i \times x_i \]

Vapor Pressure of Component 1 (P₁):

Mole Fraction of Component 1 (x₁):

Vapor Pressure of Component 2 (P₂):

Mole Fraction of Component 2 (x₂):

Solution Vapor Pressure (Pa):

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1. What is a Vapor Pressure Calculator?

Definition: This calculator estimates the vapor pressure of a solution based on the vapor pressures of its components and their mole fractions using Raoult's Law.

Purpose: It helps chemists, engineers, and students determine the vapor pressure of mixtures, which is important for understanding evaporation rates, boiling points, and phase behavior.

2. How Does the Calculator Work?

The calculator uses Raoult's Law formula:

\[ P = \sum P_i \times x_i \]

Where:

\( P \) — Vapor pressure of the solution (Pa)
\( P_i \) — Vapor pressure of pure component i (Pa)
\( x_i \) — Mole fraction of component i in the liquid phase (dimensionless)

Explanation: The total vapor pressure is the sum of each component's pure vapor pressure multiplied by its mole fraction in the liquid.

3. Importance of Vapor Pressure Calculation

Details: Vapor pressure determines a liquid's evaporation rate, affects boiling points, and is crucial for distillation processes, chemical reactions, and environmental studies.

4. Using the Calculator

Tips: Enter the vapor pressure and mole fraction for each component. For binary mixtures, x₂ will automatically calculate as (1 - x₁) if left empty. All mole fractions must be between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What is Raoult's Law?
A: Raoult's Law states that the vapor pressure of an ideal solution depends on the vapor pressure of each component and its mole fraction.

Q2: When is Raoult's Law valid?
A: For ideal solutions where intermolecular forces between different molecules are similar to those between like molecules.

Q3: What if my solution is non-ideal?
A: For non-ideal solutions, you would need activity coefficients or other models like Henry's Law for dilute solutions.

Q4: How do I find pure component vapor pressures?
A: They can be found in chemical handbooks or calculated using Antoine equation if temperature is known.

Q5: Can I calculate for more than two components?
A: This calculator handles up to two components, but Raoult's Law can be extended to any number of components.