Question

A colourless non-irritant lightly toxic gas that impairs respiration is

• A. Sulphur dioxide
• B. Nitrous oxide
• C. Carbon dioxide
• D. Carbon monoxide

Answer 1

The correct option is D Carbon monoxide

Carbon monoxide is a light and toxic gas which impairs the process of respiration. The affinity of the carbon monoxide towards haemoglobin is more compared to the affinity towards oxygen which results in the binding of carbon monoxide with haemoglobin, forming carboxyhemoglobin. There are very less sites for oxygen binding and transport of the oxygen is reduced in the body which is known as carbon monoxide poisoning. Due to lack of oxygen, the process of respiration is hampered.

Thus, the correct answer is option D.