Question

How is Le Chatelier’s principle used to treat CO poisoning?

Answer 1

The Le Chatelier’s principle states that when the dynamic equilibrium of the reaction is disturbed by changing the conditions, the position of the equilibrium shifts to regain the equilibrium. When the chemical reaction is at equilibrium and change in pressure, temperature, or concentration takes place, the equilibrium shifts to the opposite direction.

Complete step by step answer: When we breath and the oxygen moves inside and gets dissolved in the blood which further binds with the hemoglobin in the red blood in a reversible reaction.
The reaction is given as shown below.
$Hb(aq) + 4{O_2}(aq) \rightleftharpoons Hb{({O_2})_4}(aq)$
The carbon monoxide binds with the hemoglobin more tightly than the oxygen.
$Hb(aq) + 4CO(aq) \rightleftharpoons Hb{(CO)_4}(aq)$
When we reverse the first reaction and add the second reaction to it, the new reaction which is formed is shown below.
$Hb{({O_2})_4}(aq) + 4CO(aq) \rightleftharpoons Hb{(CO)_4}(aq) + 4{O_2}(aq)$
The bond between the hemoglobin and the carbon monoxide is much stronger than the bond between the hemoglobin and oxygen, so the equilibrium lies to the right side of the reaction.
The formation of $Hb{(CO)_4}$ causes carbon monoxide poisoning which results in the lack of oxyhemoglobin in the body to maintain the life processes.
Le Chatelier’s principle states that by applying stress to the system at the equilibrium, the equilibrium will shift toward the direction that will remove the stress.
Thus, by giving pure oxygen, the reaction can be reversed.
When the concentration of oxygen is increased, the system will try to decrease the concentration of carbon monoxide. Thus, the position of the equilibrium will shift to the left and produces more $Hb{({O_2})_4}$
In this way Le Chatelier’s principle is used to treat CO poisoning.

Note:
This process is usually slow. It takes approximately 74 minutes to remove half of the monoxide by breathing pure oxygen and 320 min by breathing normal air.