Question

When a man inhales air containing normal concentration of O₂ as well as CO he suffers from suffocation because

(a) CO reacts with O₂ reducing its percentage in air

(b)  haemoglobin combines with CO instead of O₂ and froms carboxyhaemoglobin

(c) CO affects diaphragm and intercostal muscles

(d) CO affects the nerves of the lungs

Answer 1

The correct option is (b)  haemoglobin combines with CO instead of O₂ and froms carboxyhaemoglobin.

Explanation:

Affinity of carbon monoxide for haemoglobin is 200 times more than oxygen. At 0.5 partial pressure, CO combines with 50% of haemoglobin. It produces a relatively stable compound called carboxy-haemoglobin. This causes low supply of oxygen to the body which is characterised by headache, dizziness, nausea, etc.