Chemistry:Anson equation

In electrochemistry, the Anson equation defines the charge-time dependence for linear diffusion control in chronocoulometry.

The Anson equation is written as:

[math]\displaystyle{ Q = nFACD^{1/2}\pi^{-1/2}t^{1/2} }[/math]

where,

Q = charge in coulombs

n = number of electrons (to reduce/oxidize one molecule of analyte)

F = Faraday constant, 96485 C/mol

A = area of the (planar) electrode in cm²

C = concentration in mol/cm³;

D = diffusion coefficient in cm²/s

t = time in s.

This is related to the Cottrell equation via integration with respect to time (t), and similarly implies that the electrode is planar.

See also

• Voltammetry
• Electroanalytical methods
• Limiting current
• Cottrell equation