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THE CALCULATORS

Fick's Law for Steady-State Diffusion

Calculates the molar and mass diffusion rates of a species through a stagnant medium under steady-state conditions using concentration gradients derived from partial pressures.

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1. Define Input Parameters

2. Engineering Output

Absolute Temperature (T_k)
- K
Upstream Molar Concentration (C1)
- kmol/m³
Downstream Molar Concentration (C2)
- kmol/m³
Molar Diffusion Rate (N_dot)
- kmol/s
Mass Diffusion Rate (kg/s) (m_dot_s)
- kg/s
Mass Diffusion Rate (mg/h) (m_dot_h)
- mg/h

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Context & Assumptions

Fick’s first law quantifies the steady-state movement of species through a medium based on constant concentration gradients. It is a fundamental tool in process engineering for sizing membranes, predicting solvent losses, and designing catalytic layers. The law serves as the mass-transfer analogue to Ohm's law, linking driving force to molar flux.

Understand the Engineering Principles

Review the step-by-step derivations, typical industrial limits, and scale-up rules.

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