Activity Coefficient Formula:
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Definition: The activity coefficient (γ) quantifies the deviation of a component's behavior from ideal solution behavior in vapor-liquid equilibrium (VLE).
Purpose: It's crucial for accurate phase equilibrium calculations in chemical engineering and thermodynamics.
The calculator uses the formula:
Where:
Explanation: This formulation relates the vapor and liquid phase compositions through thermodynamic coefficients and pressures.
Details: Accurate γ values are essential for designing distillation columns, predicting phase behavior, and modeling chemical processes.
Tips: Enter all required parameters. Mole fractions should be between 0 and 1. All other values must be positive.
Q1: What does an activity coefficient of 1 mean?
A: γ=1 indicates ideal solution behavior where Raoult's Law applies perfectly.
Q2: How do I obtain the fugacity coefficient?
A: φ can be calculated from equations of state or obtained from experimental data.
Q3: What are typical values for activity coefficients?
A: γ can range from 0 to ∞, but typically between 0.1 and 10 for most systems.
Q4: When would I need this calculation?
A: For non-ideal VLE systems common in hydrocarbon processing, alcohol-water mixtures, etc.
Q5: What if my γ result is very large or very small?
A: Extreme values may indicate azeotropic behavior or immiscibility - verify your inputs.