The image above represents chemical breakthrough time.

To compute for chemical breakthrough time, two essential parameters are needed and these parameters are **Thickness (l)** and **Diffusion Coefficient (D).**

The formula for calculating chemical breakthrough time:

t_{b} = ^{l²}/_{6D}

Where:

t_{b} = Chemical Breakthrough Time

l = Thickness

D = Diffusion Coefficient

Let’s solve an example;

Find the chemical breakthrough time when the thickness is 14 and the diffusion coefficient is 7.

This implies that;

l = Thickness = 14

D = Diffusion Coefficient = 7

t_{b} = ^{l² }/ _{6D}

t_{b} = ^{14²}/_{6(7)}

t_{b} = ^{196}/_{42}

t_{b} = 4.66

Therefore, the **chemical breakthrough time **is **4.66 s.**

**Calculating the Thickness when the Chemical Breakthrough Time and the Diffusion Coefficient is Given.**

l = √t_{b} x 6D

Where;

l = Thickness

t_{b} = Chemical Breakthrough Time

D = Diffusion Coefficient

Let’s solve an example;

Find the thickness when the chemical breakthrough time is 5 and the diffusion coefficient is 20.

This implies that;

t_{b} = Chemical Breakthrough Time = 5

D = Diffusion Coefficient = 20

l = √t_{b} x 6D

l = √5 x 6(20)

l = √5 x 120

l = √600

l = 24.49

Therefore, the **thickness **is **24.49.**