Question

Which one of the following is not normally a pollutant?

• A. Carbon monoxide
• B. Carbon dioxide
• C. Hydrocarbons
• D. Sulphur dioxide

Answer 1

The correct option is B

Carbon dioxide

The common gaseous pollutants are oxides of carbon (CO and CO2), oxides of nitrogen (NO and NO2) oxides of sulphur (SO2 and SO3), all these together contribute 90% of the global air pollution. Out of all these CO2 is not a pollutant normally, the green plants, by photosynthesis balance the CO2 and O2 ratios in the air to a great extent, whereas others like carbon monoxide, NO2 etc. are poisonous gases.