Question

Carbon monoxide gas is more dangerous than carbon dioxide gas. Why?

Answer 1

CO is poisionous and $C{O}_2$ is non toxic in nature.
CO forms complex with haemoglobin which is more stable than complex of oxygen with haemoglobin. The concentration range of 3-4 % of CO decreases the oxygen carrying capacity of blood. This causes headache, weak eyesight, nervousness and cardiovascular disorders. Higher concentration can be fatal. $C{O}_2$ is harmful at very high concentration.