Atmospheric pressure is 1.00 atm, but air is only composed of 21.0% (by moles) oxygen. thus, the partial pressure of oxygen in air is less than 1.00 atm. what is the millimolar concentration of dissolved oxygen for a lake or stream under the partial pressure of oxygen and a temperature of 12 ∘c?

Respuesta :

The solubility of Oxygen at given temperature (12 ∘c) is 10.766 mg/ L

The moles of oxygen in one litre will be

[tex]moles of oxygen = \frac{mass}{molar mass} = \frac{10.766mg}{32} =   0.336 mmoles[/tex]

Molarity is moles of solute per litre of solution

so molarity will be

[tex]Molarity = \frac{0.336 mmoles}{1 L} = 0.336 X 10^{-3} M[/tex]