Air and Environment Flashcards
What does the catalytic converter do?
Causes carbon monoxide to react with oxides of nitrogen
CO + NOx –> CO2 + N2
Causes unburnt hydrocarbons to undergo combustion –> CO2 + H2O
Source of carbon monoxides
Incomplete combustion of carbon-containing fuel
Harmful effects of carbon monoxide
Binds to haemoglobin, reduces amount of oxygen transported to the body
Sources of oxides of nitrogen
Lightning activity
Combustion of nitrogen gas
Harmful effects of oxides of nitrogen
Formation of acid rain (nitric acid), corroding buildings
How to remove oxides of nitrogen
Pass the gases through wet calcium oxide
Sources of sulfur dioxide
Volcanic eruptions
Combustion of fossil fuels which contain sulfur
Harmful effects of sulfur dioxide
Formation of acid rain (sulfuric acid)
Sulfur dioxide + oxygen + water –> sulfuric acid
How to remove sulfur dioxide
Pass sulfur dioxide through wet calcium oxide
[flue gas desulfurisation]
Source of methane & unburnt hydrocarbons
Bacterial decay of vegetable matter
Internal combustion engines of vehicles when fuel is not burnt
Harmful effects of methane & unburnt hydrocarbons
Greenhouse effects
Sources of chlorofluorocarbons (CFCs)
Propellants for aerosols and coolants in refrigerators & air conditioners
Harmful effects of CFCs
CFCs release chlorine radicles & break down ozone
Ozone depletion!!!
How to prevent CFCs?
Reduce usage of CFCs
Use HFCs instead
Sources of ground level ozone
Photochemical reactions
When oxides of nitrogen, carbon monoxides and volatile organic compounds react in the atmosphere in the presence of sunlight
