Given the Henry’s law constant for O2(4.34*109Pa) at 25° C, calculate the molar concentration of oxygen in air-saturated and O2saturated water. (4 points)

This is an incomplete question, here is a complete question.

The Henry's law constant for oxygen dissolved in water is 4.34 × 10⁹ g/L.Pa at 25⁰C.If the partial pressure of oxygen in air is 0.2 atm, under atmospheric conditions, calculate the molar concentration of oxygen in air-saturated and oxygen saturated water.

Answer : The molar concentration of oxygen is,

Explanation :

As we know that,

where,

= molar solubility of = ?

= partial pressure of = 0.2 atm  = 1.97×10⁻⁶ Pa

= Henry's law constant  = 4.34 × 10⁹ g/L.Pa

Now put all the given values in the above formula, we get:

Now we have to molar concentration of oxygen.

Molar concentration of oxygen =

Therefore, the molar concentration of oxygen is,

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

it is the most commonly accepted one