Fish need at least 4 ppm dissolved O_{2} for survival.

What is this concentration in mol/L?

We’re being asked to determine the molarity of 4 ppm dissolved O_{2}. Let’s first define **ppm** and **ppb**.

• **1 ppm means 1 part of solute for every 10 ^{6} parts of the solution**

*in terms of solutions:*

$\overline{){\mathbf{p}}{\mathbf{p}}{\mathbf{m}}{\mathbf{=}}\frac{\mathbf{\mu}\mathbf{g}\mathbf{}\mathbf{s}\mathbf{o}\mathbf{l}\mathbf{u}\mathbf{t}\mathbf{e}}{\mathit{m}\mathit{L}\mathbf{}\mathbf{s}\mathbf{o}\mathbf{l}\mathbf{u}\mathbf{t}\mathbf{i}\mathbf{o}\mathbf{n}}}$

• **1 ppb means 1 part of solute for every 10 ^{9} parts of the solution**

ppm