The surface area of the lungs is about 70m² and the thickness of the alveolar diffusion layer is about 0.5 µm. The PaO₂ is about 100 mm Hg, whereas the PvO₂, the partial pressure of O₂ in venous blood, is about 40 mm Hg. The diffusion coefficient of O₂ in water is about 1.5 x 10⁻⁵ cm² s⁻¹. The solubility of O₂ is given by Henry’s law with a coefficient α. This gives [O₂] = 0.024 PO₂ where [O₂] is expressed in mL O₂ per mL of water and PO₂ is in atmospheres. Only the dissolved O₂ diffuses. What is the initial rate of O₂ diffusion from the aggregate alveoli to the blood?