Which of the following are correct with respect to carbon monoxide?
(i) It is released due to incomplete combustion of fuels.
(ii) It does not affect humans.
(iii) It is a poisonous gas.
(iv) It reduces oxygen-carrying capacity of the blood.
(v) It is released from vehicles.
(i), (iii), (iv) and (v)
Incomplete burning of a fuel (carbon-based) happens due to insufficient supply of oxygen gas for combustion. This leads to the formation of carbon monoxide which is odourless, colourless and toxic gas.
Carbon monoxide gas, when inhaled, combines with blood and reduces the oxygen-carrying capacity of Haemoglobin, thereby damaging the nervous system and even causing death. Automobiles are a major contributor to carbon monoxide.