Molar Flux Formula:
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Definition: Molar flux (NA) is the amount of substance (in moles) that diffuses through a unit area per unit time.
Purpose: This calculator determines the molar flux of component A through non-diffusing component B based on the partial pressures of B.
The calculator uses the formula:
Where:
Explanation: The formula calculates the molar flux based on the logarithmic mean partial pressure difference of component B.
Details: Accurate calculation of molar flux is essential for designing separation processes, mass transfer equipment, and understanding diffusion phenomena in chemical engineering.
Tips: Enter all required parameters with appropriate units. Default values are provided for reference. All values must be positive.
Q1: What is the physical significance of the diffusion coefficient?
A: The diffusion coefficient (DAB) measures how easily component A diffuses through component B under a concentration gradient.
Q2: Why do we use partial pressures of component B to calculate flux of component A?
A: This approach is valid when component B is non-diffusing (stationary), and the flux is driven by the concentration gradient of B.
Q3: What are typical values for the diffusion coefficient?
A: For gases, typical values range from 10-6 to 10-5 m²/s, while for liquids they're typically 10-10 to 10-9 m²/s.
Q4: How does temperature affect molar flux?
A: Higher temperatures generally increase diffusion coefficients and thus increase molar flux, though the exact relationship depends on the system.
Q5: What is the film thickness in this context?
A: The film thickness represents the effective distance over which the concentration gradient exists in the diffusion process.