Thread: How to create a gas/liquid solution with known concentration.

I need to create a solution of oxygen and water with known concentration of oxygen. Both are mixed in a vessel where I can control and measure the pressure and temperature.
The idea is to add oxygen to the water in the vessel, measure the increase of pressure and calculate the oxygen concentration with the equation of state for ideal/real gases. The problem is that some oxygen will dilute fastly in the water so that this relationship isn't exact anymore.
Any ideas?

You could try using Henry's Law https://en.m.wikipedia.org/wiki/Henry's_law
If you know the Henry coefficient at the temperature of interest you can calculate the concentration of oxygen dissolved in the water from the pressure of oxygen above the liquid

Originally Posted by sellollo

I need to create a solution of oxygen and water with known concentration of oxygen. Both are mixed in a vessel where I can control and measure the pressure and temperature.
The idea is to add oxygen to the water in the vessel, measure the increase of pressure and calculate the oxygen concentration with the equation of state for ideal/real gases. The problem is that some oxygen will dilute fastly in the water so that this relationship isn't exact anymore.
Any ideas?

Perhaps instead of creating a solution of known oxygen concentration and measuring the pressure, you could control the pressure and measure the oxygen concentration.