Formula Used:
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Definition: The activity coefficient for infinite dilution (γ₁∞) is a measure of non-ideality of a component in a mixture when its concentration approaches zero.
Purpose: It helps chemical engineers and researchers understand how a component behaves in extremely dilute solutions, which is important for separation processes and thermodynamic modeling.
The calculator uses the NRTL (Non-Random Two-Liquid) model formula:
Where:
Explanation: The formula accounts for both energetic (b parameters) and structural (α parameter) differences between molecules.
Details: Accurate calculation of activity coefficients is crucial for designing distillation columns, liquid-liquid extraction systems, and predicting phase equilibria.
Tips: Enter the NRTL parameters (b21, b12, α) and temperature. Default values are provided based on typical values, but these should be adjusted for specific systems.
Q1: What are typical values for NRTL parameters?
A: b parameters typically range from -1000 to 3000 J/mol, while α is usually between 0.2 and 0.5 for most systems.
Q2: Why is temperature important in this calculation?
A: The activity coefficient depends on temperature because molecular interactions change with thermal energy.
Q3: What does infinite dilution mean?
A: It refers to the condition where the concentration of component 1 approaches zero in the mixture.
Q4: How do I obtain NRTL parameters for my system?
A: Parameters are typically determined by fitting experimental vapor-liquid or liquid-liquid equilibrium data.
Q5: Can this calculator be used for any binary system?
A: Yes, as long as you have the correct NRTL parameters for your specific system.