Liquid Phase Mole Fraction using Modified Raoult's Law in VLE Calculator

Liquid Phase Mole Fraction Formula:

\[ x_{liquid} = \frac{y_{gas} \times P_T}{\gamma_{Raoults} \times P_{sat}} \]

Mole Fraction in Vapor Phase (y_gas):

Total Gas Pressure (P_T):

Activity Coefficient (γ_Raoults):

Saturated Pressure (P_sat):

Liquid Phase Mole Fraction (x_liquid):

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1. What is Liquid Phase Mole Fraction using Modified Raoult's Law?

Definition: This calculator determines the mole fraction of a component in the liquid phase using Modified Raoult's Law for vapor-liquid equilibrium (VLE) calculations.

Purpose: It helps chemical engineers and researchers predict the composition of liquid mixtures in equilibrium with their vapor phase.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ x_{liquid} = \frac{y_{gas} \times P_T}{\gamma_{Raoults} \times P_{sat}} \]

Where:

\( x_{liquid} \) — Mole fraction in liquid phase
\( y_{gas} \) — Mole fraction in vapor phase
\( P_T \) — Total system pressure (Pa)
\( \gamma_{Raoults} \) — Activity coefficient (accounts for non-ideality)
\( P_{sat} \) — Saturation pressure of pure component (Pa)

Explanation: The formula relates the liquid composition to the vapor composition through pressure terms and activity coefficients.

3. Importance of VLE Calculations

Details: Accurate VLE calculations are essential for designing distillation columns, evaporators, and other separation processes in chemical engineering.

4. Using the Calculator

Tips: Enter the vapor phase mole fraction (0-1), total pressure, activity coefficient (default 1.0 for ideal systems), and saturation pressure. All values must be > 0 except y_gas which can be 0.

5. Frequently Asked Questions (FAQ)

Q1: What is Modified Raoult's Law?
A: It's an extension of Raoult's Law that includes activity coefficients to account for non-ideal behavior in liquid mixtures.

Q2: When is the activity coefficient 1.0?
A: For ideal mixtures where components have similar molecular size and intermolecular forces.

Q3: How do I find saturation pressure?
A: From vapor pressure tables or correlations like Antoine equation for the pure component at system temperature.

Q4: What if my result is greater than 1?
A: This indicates invalid input as mole fractions must be ≤1. Check your pressure and activity coefficient values.

Q5: Can this be used for multicomponent systems?
A: This calculator is for binary systems. Multicomponent systems require more complex calculations.