Diffusion Coefficient Formula:
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Definition: This calculator determines the diffusion coefficient (D) using the Ilkovic equation based on measured diffusion current and other parameters.
Purpose: It helps electrochemists and researchers analyze polarographic measurements and understand diffusion processes in electrochemical systems.
The calculator uses the Ilkovic equation:
Where:
Explanation: The equation relates the diffusion current measured in polarography to the diffusion coefficient of the electroactive species.
Details: The diffusion coefficient is crucial for understanding mass transport in electrochemical systems, reaction kinetics, and designing electrochemical experiments.
Tips: Enter all parameters with correct units. Typical values:
Q1: What is the significance of the constant 607?
A: This constant combines several fundamental constants and conversion factors specific to mercury electrodes in the Ilkovic equation.
Q2: How does temperature affect the diffusion coefficient?
A: Diffusion coefficient increases with temperature (typically 2-3% per °C), but this calculator assumes standard conditions.
Q3: What's a typical range for diffusion coefficients?
A: For most ions in aqueous solutions at 25°C, D ranges from 0.5×10⁻⁹ to 2×10⁻⁹ m²/s.
Q4: Why is mercury used in polarography?
A: Mercury's reproducible surface, wide potential window, and renewable electrode surface make it ideal for polarographic measurements.
Q5: How accurate is the Ilkovic equation?
A: It provides good approximations for spherical diffusion to small mercury drops, though modern refinements exist for greater precision.