Fig. 3
Illustration of the two oxidation rate regimes. [3]

The equation d_{0}^{2} + Ad_{0}
=B(t+t) has two important limiting
conditions:

1.
One limiting case occurs for long oxidation times and we
get

**d _{0}^{2} = Bt**

This is called **Parabolic Law** and B is the parabolic
rate constant. This is
diffusion-controlled case.

2.
For short oxidation times we get

**d _{0} = B(t+**

This is called **Linear Law** and B/A is called the linear
rate constant and it is a reaction-controlled case. [3] [2]