Consider human body. A 70 kg human has about 5 L of blood and it is pumped by heart at about 5.2 LPM (liter of liquid blood per minute). At any given time, the lungs transfer oxygen from alveoli to blood capillaries and the oxygen concentration in blood capillaries is given as 200 mL of O2 per L of blood (5 % of this oxygen is in dissolved state i.e O2 molecules sandwiched between H2O molecules while 95% is tied to Haemoglobin Hb i.e O2 molecules chemically bound to Hb. The concentration of Hb is 160 g/L and M=68800 g/mole. You do not this information for problem). Note that the mL of O2 is gas volume equivalent at CST (called Chemists standard temperature of 0 C and pressure of 101 kPa) while L of blood represents liquid blood of density1.06 g/cm3.

a) Based on your knowledge of ideal gas law, express the concentration of for O2 in g of O2 per g of blood.

b) How much oxygen (in g) is contained in 5 L of blood?

c) What is the oxygen pumping rate in g per minute?

d) However 75 % of this oxygen is returned back to alveoli which you breathe out. Thus only 25 % oxygen is used for burning glucose (i.e. Glucose delivered to blood from the food you ate three times a day) called metabolism in biology. How much oxygen in g/min is used for metabolism?

e) If 14500 J of energy is released per g of O2 used for metabolism, what is the energy released rate of human in Watts.

{Almost 20 % of this energy is used by your brain, a super-super-.. Einstein living with everyone on globe which controls all our functions; so even a few min of absence oxygen flow to brain may leads to death. Just like automobile engine you breathe in 360 Liters per hour and instead of gasoline you burn glucose and/or fat 24 hrs per day 7 days per week, … until human engines stop}