Answer to Question #164885 in General Chemistry for Nesma Mahmoud

Question

Our bodies absorb oxygen (O2) through our lungs, then distribute this oxygen to our muscles and organs. We have found that the average person has 0.0423 g O2 in their blood. 

(a) If the average person has 4.70 L of blood in their bodies, what is the concentration of oxygen (in Molarity) in the average person’s blood? (assume that blood is just water)

 

 

​(b) A person can go into shock if they lose too much blood. What mass (g) of oxygen would be lost if a person lost 0.78 L of blood?

Answer 1

(a) Molar mass of O₂ = 32 g/mol

Average mass of O₂ in blood = 0.0423 g

Moles of O₂ = $\dfrac{0.0423}{32}=1.321875\times10^{-3} mol$

Volume of Blood = 4.70 L

$\therefore$ Molarity = $\dfrac{1.321875\times10^{-3}}{4.70}\dfrac{mol}{L}$

Molarity = $2.8125\times10^{-4}mol/L$

(b) 1L of blood contains = $2.8125\times10^{-4}$ moles of O₂

0.78 L of blood contains = $2.8125\times10^{-4}\times0.78$ moles of O₂

= $2.19375\times10^{-4}$ moles of O₂

Mass of O₂ lost = $2.19375\times10^{-4}\times32$ g

= $7.02\times10^{-3}$ g