Question

Which of the following is not correct about carbonmonoxide ?

• A. It forms carboxyhaemoglobin.
• B. It reduces oxygen carrying ability of blood.
• C. The carboxyhaemoglobin (haemoglobinbound to CO) is less stable thanoxyhaemoglobin.
• D. It is produced due to incomplete combustion.

Answer 1

The Correct Option is C

The question asks us to identify the incorrect statement about carbon monoxide (CO) from the given options.

1. Statement Analysis: 

"It forms carboxyhaemoglobin."

This is a correct statement. Carbon monoxide binds with hemoglobin to form carboxyhaemoglobin, reducing the blood's ability to carry oxygen.

"It reduces oxygen carrying ability of blood."

This statement is true. When carbon monoxide forms carboxyhaemoglobin, it significantly reduces hemoglobin's ability to carry oxygen, leading to potential hypoxic conditions.

"The carboxyhaemoglobin (hemoglobin bound to CO) is less stable than oxyhaemoglobin."

This statement is incorrect. Carboxyhaemoglobin is actually more stable than oxyhaemoglobin. Carbon monoxide binds to hemoglobin with higher affinity (approximately 240 times stronger) than oxygen, making this binding more stable and persistent.

"It is produced due to incomplete combustion."

This statement is correct. Carbon monoxide is formed during the incomplete combustion of carbon-containing fuels, where there is insufficient oxygen for complete combustion to carbon dioxide (CO₂).

Thus, the correct answer is:

The carboxyhaemoglobin (haemoglobin bound to CO) is less stable than oxyhaemoglobin.

because it is the only incorrect statement regarding carbon monoxide.