1. What is Molar Flux of Diffusing Component A?

Definition: Molar flux (N_A) is the amount of substance (in moles) that passes through a unit area per unit time during diffusion.

Purpose: This calculator determines the molar flux of component A in an equimolar counter-diffusion system based on concentration differences.

2. How Does the Calculator Work?

The calculator uses Fick's first law of diffusion:

Where:

• \( N_A \) — Molar flux of component A (mol/(s·m²))
• \( D_{AB} \) — Diffusion coefficient of A in B (m²/s)
• \( \delta \) — Film thickness (m)
• \( C_{A1} \) — Concentration of A at position 1 (mol/m³)
• \( C_{A2} \) — Concentration of A at position 2 (mol/m³)

Explanation: The flux is directly proportional to the concentration gradient and diffusion coefficient, and inversely proportional to the diffusion path length.

3. Importance of Molar Flux Calculation

Details: Accurate flux calculations are essential for designing separation processes, chemical reactors, and mass transfer equipment.

4. Using the Calculator

Tips: Enter the diffusion coefficient, film thickness, and concentrations at both positions. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is equimolar counter-diffusion?
A: It's when two components diffuse at equal molar rates in opposite directions, common in binary systems.

Q2: How do I determine the diffusion coefficient?
A: D_AB can be found experimentally or estimated using empirical correlations.

Q3: What affects the film thickness?
A: Flow conditions, system geometry, and physical properties influence the boundary layer thickness.

Q4: Can this be used for non-equimolar diffusion?
A: No, this calculator is specifically for equimolar counter-diffusion cases.

Q5: What units should I use?
A: Use consistent SI units: meters for length, seconds for time, and moles per cubic meter for concentration.