The partial pressure of O2 in your lungs varies from 25 mm Hg to 40 mm Hg. What mass of O2 can dissolve in 1.0L OF water at 25.0oC when the O2 partial pressure is 40. mm Hg?

Answer 1

p = kC
partial pressure = k*C (in molarity)
k = 769.2 L*atm/mol
Plug in 40 mm O2 (convert to atm first) and k and solve for C (in mols/L).
Convert to grams.