# What is the solubility of oxygen in water? Give references for your answer. I saw some that said cc/gm or something like that.

Jun 24, 2017

We'll try, and I see Truong-Son N. has already tried; here is another attempt......

#### Explanation:

I think you mean $g \cdot c {m}^{-} 3$ rather than $c m \cdot {g}^{-} 1$, and the former units mean precisely the same as $g \cdot m {L}^{-} 1$. Why?

$1 \cdot c {m}^{3} = {\left(1 \times {10}^{-} 2 \cdot m\right)}^{3}$. Why? Because the prefix $\text{centi} \equiv {10}^{-} 2$. And thus............

$1 \cdot c {m}^{3} = {\left(1 \times {10}^{-} 2 \cdot m\right)}^{3} = 1 \times {10}^{-} 6 \cdot {m}^{3}$.

Sometimes I remember that $1 \cdot {m}^{3}$ (which is a HUGE volume!), is $1000 \cdot L$, and that there are ${10}^{3} \cdot c {m}^{3}$ in a $L$. An equivalent term for the $\text{litre}$ is $\text{cubic decimeter}$, ${\mathrm{dm}}^{3}$.

And thus $1000 \cdot L = {10}^{3} \cdot L \times {10}^{-} 6 \cdot {m}^{3} = 1 \times {10}^{-} 3 \cdot {m}^{3}$.

Equivalently $1 \cdot L = 1 \cdot {\mathrm{dm}}^{3} = {\left(1 \times {10}^{-} 1 \cdot m\right)}^{3} = {10}^{-} 3 \cdot {m}^{3}$, as required.

If I have muddied the waters, I apologize.........

Jun 24, 2017

Depends on what temperatures you want though, because this is experimentally determined.

Here's a graph based on the above reference, for the solubility of ${\text{O}}_{2} \left(g\right)$ IN AIR in water from ${0}^{\circ} \text{C}$ to ${40}^{\circ} \text{C}$ in ${0.5}^{\circ} \text{C}$ increments at $\text{760 torr}$ atmospheric pressure.

For pure oxygen in water, divide the solubility by the mol fraction of oxygen in air, $0.21$:

Here's the data for oxygen in air, in one spreadsheet page:

The units are milligrams per liter of solution for the solubility. Or, another option is that I've also converted the solubility to molarity:

$\cancel{\text{mg"/"L" xx cancel"1 g"/(1000 cancel"mg") xx "1 mol O"_2/(31.998 cancel"g") = "mol O"_2/"L soln}}$

And also the pure oxygen version: