The image of concentration polarization is shown below.

To compute for concentration polarization, six essential parameters are needed and these parameters are **Gas Constant (R), Temperature (T), Number of Electrons (n), Faraday’s Constant (F), Current Density (i)** and **Limiting Diffusion Current Density (i _{L}).**

The formula for calculating concentration polarization:

η_{c} = ^{2.3RT}/_{nF} log(1 – ^{i}/_{iL})

Where:

η_{c} = Concentration Polarization

R = Gas Constant

T = Temperature

n = Number of Electrons

F = Faraday’s Constant

i = Current Density

i_{L} = Limiting Diffusion Current Density

Let’s solve an example;

Find the concentration Polarization when the gas constant is 14, the temperature is 7, the number of electrons is 8, the faraday’s constant is 4, the current density is 1 and the limiting diffusion current density is 2.

This implies that;

R = Gas Constant = 14

T = Temperature = 7

n = Number of Electrons = 8

F = Faraday’s Constant = 4

i = Current Density = 1

i_{L} = Limiting Diffusion Current Density = 2

η_{c} = ^{2.3RT}/_{nF} log(1 – ^{i}/_{iL})

η_{c} = ^{2.3(14)(7)}/_{(8)(4)} log(1 – (^{1}/_{2}))

η_{c} = ^{225.39}/_{32} log(1 – 0.5)

η_{c} = 7.043749 log(0.5)

η_{c} = 7.043749 (-0.301029)

η_{c} = -2.120

Therefore, the **concentration polarization **is **-2.120.**

Continue reading How to Calculate and Solve for Concentration Polarization | Corrosion