How can you find partial pressure?
Partial is a pressure of inert gases in a mixture of gases.
For example air is a mixture of gases like oxygen, nitrogen and carbondioxide. At room temperature and normal pressure of 760 mm Hg these gases are inert.
Partial pressure is a pressure of gases in a mixture as per it's percentage .
Oxygen is 20.96 % of 760 mm Hg. Therefore partial pressure of oxygen is 20% of 760mm Hg.
Partial pressure of nitrogen would be 78% of 760 mm Hg.
Partial pressure of CO 2 is .03% of 760 mm Hg.
In respiration these gases are important.
Because this partial pressure determines which way gases are to diffuse.