Question

Carbon monoxide is a pollutant because:
A. It reacts with ${O_2}$.
B. It inhibits glycolysis.
C. Makes the nervous system inactive.
D. Reacts with haemoglobin.

Answer 1

Try to recall that carbon monoxide is a neutral oxide and has the ability to form a complex with haemoglobin (carboxyhemoglobin). Now, by using this you can easily find the correct option from given options.
Complete step by step solution:
It is known to you that blood contains RBC’s (Red Blood Corpuscles) which have haemoglobin (Hb) pigment. Hb is the key element for transportation of oxygen to all over the body.
In our lungs, oxygen attaches to Hb and forms an oxyhemoglobin complex. This complex breaks and releases oxygen when reaching a cell which needs oxygen.
When a carbon monoxide (CO) atom goes into lungs, it gets attached to Hb and forms. carboxyhemoglobin which is about 300 times more stable than the oxyhaemoglobin complex.
This prevents haemoglobin present in the red blood cells from carrying oxygen from the lungs to all parts of the body thereby causing suffocation ultimately leading to death.
So, carbon monoxide is highly toxic in nature and its toxic nature is due to its higher affinity for haemoglobin and its ability to form stable carboxyhemoglobin complex with haemoglobin.

Therefore, from above we can conclude that option D is the correct option to the given question.

Note: It should be remembered to you that carbon monoxide is a powerful reducing agent and it reduces many metal oxides to their respective metals.
Also, you should remember that it is used in Mond’s process for purification of nickel via its nickel carbonyl.