If the average volume of blood in the human body is 4.8 L and the average concentration of oxygen in blood is 0.0070M what is the total amount of 2 in an average human body?

A concentration of .0070M indicates that there is .007 moles per liter, so in total there are .0336 moles of O2 in the body. This is equal to 1.08 grams or 752 milliliters of O2.