1. What is Vapour Phase Mole Fraction using Henry Law?

Definition: This calculator determines the mole fraction of a component in the vapour phase at equilibrium using Henry's Law for vapor-liquid equilibrium (VLE) systems.

Purpose: It helps chemical engineers and researchers predict the distribution of components between phases in non-ideal systems.

2. How Does the Calculator Work?

The calculator uses Henry's Law formula:

Where:

• \( y_{Gas} \) — Mole fraction in vapour phase (dimensionless)
• \( x_{Liquid} \) — Mole fraction in liquid phase (dimensionless, 0-1)
• \( K_H \) — Henry's Law constant (Pa·m³/mol)
• \( P_T \) — Total system pressure (Pa)

Explanation: The liquid phase mole fraction is multiplied by Henry's constant and divided by total pressure to get the vapour phase composition.

3. Importance of Vapour Phase Mole Fraction Calculation

Details: Accurate prediction of vapour phase composition is crucial for distillation design, absorption processes, and environmental emission calculations.

4. Using the Calculator

Tips: Enter the liquid phase mole fraction (0-1), Henry's Law constant, and total pressure. All values must be positive, with x_Liquid between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: When is Henry's Law applicable?
A: Henry's Law applies to dilute solutions where the solute concentration is low and interactions between solute molecules are negligible.

Q2: What are typical units for Henry's constant?
A: Common units are Pa·m³/mol, atm·m³/mol, or bar·m³/mol. Ensure units match your pressure units.

Q3: How does temperature affect the calculation?
A: Henry's constant is temperature-dependent. Use values measured at your system temperature.

Q4: Can I use this for multi-component systems?
A: This calculates for one component. For mixtures, repeat for each component and ensure Σy_i ≤ 1.

Q5: What if my result is greater than 1?
A: This suggests invalid inputs or conditions where Henry's Law doesn't apply (high concentrations).