the average pH of healthy human blood is 7.4. how many moles of H+ ions are free in your blood. The average person has approx. 5 L of blood.

Answer 1

I assume the question is asking simply to count the H^+ free (from the pH calculation) and NOT go through the bicarbonate equilibrium.
pH = -log(H^+).
Solve this for (H^+) which gives the hydrogen ion in moles/L, then multiply by 5 to obtain the moles in 5 L.

Answer 2

so would the equation be 7.4= -log of what?