# How to Calculate and Solve for Concentration Polarization | Corrosion

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 (iL).

The formula for calculating concentration polarization:

ηc = 2.3RT/nF log(1 – i/iL)

Where:

ηc = Concentration Polarization
R = Gas Constant
T = Temperature
n = Number of Electrons
i = Current Density
iL = 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
iL = Limiting Diffusion Current Density = 2

ηc = 2.3RT/nF log(1 – i/iL)
ηc = 2.3(14)(7)/(8)(4) log(1 – (1/2))
ηc = 225.39/32 log(1 – 0.5)
ηc = 7.043749 log(0.5)
ηc = 7.043749 (-0.301029)
ηc = -2.120

Therefore, the concentration polarization is -2.120.

Nickzom Calculator – The Calculator Encyclopedia is capable of calculating the concentration polarization.

To get the answer and workings of the concentration polarization using the Nickzom Calculator – The Calculator Encyclopedia. First, you need to obtain the app.

You can get this app via any of these means:

You can also try the demo version via https://www.nickzom.org/calculator

Apple (Paid) – https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8
Once, you have obtained the calculator encyclopedia app, proceed to the Calculator Map, then click on Materials and Metallurgical under Engineering. Now, Click on Corrosion under Materials and Metallurgical Now, Click on Concentration Polarization under Corrosion The screenshot below displays the page or activity to enter your values, to get the answer for the concentration polarization according to the respective parameter which is the Gas Constant (R), Temperature (T), Number of Electrons (n), Faraday’s Constant (F), Current Density (i) and Limiting Diffusion Current Density (iL). Now, enter the values appropriately and accordingly for the parameters as required by the Gas Constant (R) is 14, Temperature (T) is 7, Number of Electrons (n) is 8, Faraday’s Constant (F) is 4, Current Density (i) is 1 and Limiting Diffusion Current Density (iL) is 2. Finally, Click on Calculate  As you can see from the screenshot above, Nickzom Calculator– The Calculator Encyclopedia solves for the concentration polarization and presents the formula, workings and steps too.