If a patient has a blood volume of 4.7L, how much H+ is in deficit?

Question

I know that is has to do with pH and hydrogen ions, but i do not know what is the correlation between volume and hydrogen ions

Answer 1

Well, what is pH? Roughly it's the negative log of the molarity of H⁺. The pH of blood is about 7.4, so you can solve

 

7.4 = -log [H⁺]

 

and find the concentration of H⁺ in moles/L.

 

Then you just multiply by the volume to find the moles of H⁺.

 

For the deficit part, do you mean in relation to pH 7 or to the OH^- ions? If the former, you follow the same steps as above, but solve for [H⁺] for pH 7. Then you subtract the pH 7.4 moles from the pH 7 moles to find the deficit.

 

If the latter, you use the equation for pOH:

 

pOH = 14 - pH = -log [OH^-]

 

Solve for the molarity of OH^-, multiply by the volume, and subtract the pH 7.4 moles from the pOH (14 - 7.4) moles.