Hb(aq) + O 2(g) ↔ HbO 2(aq)

Question

I am asked to write an equilibrium expression, and to include the term pO2 for the oxygen gas term. 

Answer 1

You can write two expressions, but if you are asked to include the pO₂ term for oxygen, then the first one that follows would be the correct one:

 

(1) Kp = [HbO_2]/[Hb]pO₂

 

(2) Kc = [HbO₂]/[Hb][O₂]