Chapter 12, Problem 61QAP

Hemoglobin (Hb) binds to both oxygen and carbon monoxide. When the carbon monoxide replaces the oxygen in an organism, the following reaction occurs:

${\text{HbO}}_2\left(aq\right)+\text{CO}\left(g\right)\rightleftharpoons \text{HbCO}\left(aq\right)+{\text{O}}_2\left(g\right)$

At 37°C, K is about 200. When equal concentrations of HbO₂ and HbCO are present, the effect of CO inhalation is fatal. Assuming $P_{{\text{O}}_2}=0.21$atm, what is P_CO when $\left[{\text{HbO}}_2\right]=\left[\text{HbCO}\right]$?