Diffusion Coefficient Formula:
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Definition: This calculator computes the diffusion coefficient (D) based on the standard deviation (σ) of particle displacement and the diffusion time (t).
Purpose: It helps in studying diffusion processes in physics, chemistry, and biology by relating the spread of particles to the diffusion coefficient.
The calculator uses the formula:
Where:
Explanation: The standard deviation squared (variance) is proportional to the diffusion coefficient and time, following Einstein's relation for Brownian motion.
Details: The diffusion coefficient quantifies how quickly particles spread out and is fundamental in understanding transport phenomena in various systems.
Tips: Enter the standard deviation of particle displacement and the diffusion time in seconds. All values must be > 0.
Q1: What is the physical meaning of standard deviation in diffusion?
A: It represents the root-mean-square displacement of particles from their starting point during the diffusion time.
Q2: What units should I use for standard deviation?
A: The standard deviation should be in meters (m) for the result to be in standard SI units (m²/s).
Q3: Does this formula work for all dimensions?
A: This is the 1D version. For 2D, divide by 4t; for 3D, divide by 6t.
Q4: What affects the diffusion coefficient?
A: Temperature, particle size, and medium viscosity primarily influence the diffusion coefficient.
Q5: How is this related to Fick's laws?
A: This is derived from Fick's second law of diffusion, relating concentration gradients to the diffusion coefficient.