Diffusion Coefficient Formula:
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Definition: This calculator determines the diffusion coefficient (DAB) of a gas pair using the twin bulb method, which measures how quickly one gas diffuses into another.
Purpose: It's essential for chemical engineering applications, gas separation processes, and understanding mass transfer phenomena.
The calculator uses the formula:
Where:
Explanation: The formula calculates how quickly component A diffuses through component B based on pressure changes in two connected bulbs over time.
Details: The diffusion coefficient is crucial for designing separation processes, predicting gas mixing rates, and modeling mass transfer in chemical reactors.
Tips: Enter all required parameters in consistent SI units. Ensure partial pressure difference (PA1 - PA2) is positive for valid calculation.
Q1: What is the typical range for diffusion coefficients?
A: For gases at standard conditions, DAB typically ranges from 10-6 to 10-5 m²/s.
Q2: Why use the twin bulb method?
A: It provides a simple experimental setup for measuring gas diffusivity with reasonable accuracy.
Q3: How does temperature affect the results?
A: Diffusion coefficients increase with temperature (≈T1.75). This calculator assumes isothermal conditions.
Q4: What if I get a negative value?
A: Check your pressure inputs - PA1 must be greater than PA2 for valid results.
Q5: How accurate is this method?
A: Accuracy depends on precise measurement of all parameters, especially the partial pressures and time.