- In a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases. Ptotal= P1+P2+….Pn
- The partial pressure of a gas is the pressure exerted by that gas on its container independent of other gases.
- Since each gas in a mixture is at the same temperature & is contained in the same volume Dalton’s law states that their individual partial pressures can be simply added to find the total
- pressure in a container.
- Pgas1= %total gas1 x Ptotal
- Example- at standard barometric pressure (760 mm Hg) oxygen is ~21% of atmospheric air.
- Therefore PO2= 0.21 x 760 mmHg = 160 mmHg