Factors affecting gas exchange △P·S·T·A D∝ d·√MW Rate of gas diffusion D△sTAd Difference of partial pressure Solubility of the gas Absolute temperature Area of diffusion Distance of diffusion MW Molecular weight▪ D: Rate of gas diffusion ▪ P: Difference of partial pressure ▪ S: Solubility of the gas ▪ T: Absolute temperature ▪ A: Area of diffusion ▪ d: Distance of diffusion ▪ MW: Molecular weight d MW P S T A D       Factors affecting gas exchange