C1 AIR QUALITY Flashcards
What are the relative proportions of the main gases in the atmosphere?
78% Nitrogen
21% oxygen
1% argon
What did earths early atmosphere consisted of?
Carbon dioxide and water vapour (formed by volcanic activity)
What is the atmosphere made of?
Nitrogen, oxygen, argon, small a mouths of water vapour, carbon dioxide and other gases
How was carbon dioxide removed and oxygen added to the atmosphere?
Because the evolution of photosynthesising organisms
Name another way carbon dioxide was removed from the atmosphere
By dissolving in the oceans and then forming sedimentary rocks, and by the formation of fossil fuels
How has human activity changed the composition of the atmosphere?
They added small amounts of carbon monoxide, nitrogen oxides and sulfur dioxide in the atmosphere. Extra carbon dioxide and small particles of solids (carbon).
Why is carbon monoxide harmful?
If reduces the amount of oxygen blood can carry
How is carbon dioxide and particulates added to the atmosphere?
- Burning fuels
- burning forests to make more farmland
- particulates are also created naturally as ash in volcanoes
What’s harmful about sulfur dioxide and nitrogen dioxide?
It creates acid rain, which damaged plants and animals
What can nitrogen oxide trigger?
(With sulfur dioxide) triggers asthma
What is coal mainly made of?
Carbon
Name compounds of hydro carbons
Petrol, diesel fuel and fuel oil - all fossil fuels
the equation when hydrocarbon fuel burns
hydro carbon + oxygen > carbon dioxide + water (+energy)
what is oxidation
oxygen is added to substance
what is reduction
oxygen is removed from substance
what is combustion
and oxidation reaction
what is created when solid yellow sulfur burns?
a colourless gass called sulfur dioxide
sulfur is insoluble but sulfur dioxide dissolves in water to make an…
acid solution
Equation for when sulfur in fossil fuels burn
sulfur + oxygen > sulfur dioxide
Name an indirect pollutant
Acid rain- does not affect humans directly
How is sulfur dioxide made?
when the fuel contains sulfur
what is always formed when fuel burns?
carbon dioxide
What happens when not enough air is available to burn the fuel?
- poisonous carbon monoxide is made
- particulares (soot) are formed - surface they labd on dirty
How does car engines contribute to acid rain?
car engines make nitrogen oxide when nitrogen and oxygen from the air react at high temperatures - contributes to acid rain
what is made when theres a n incomplete combustion?
carbon monoxide and particulate carbon
How is nitrogen monoxide formed?
in furnaces and engines at a temperature of 1000C
What happens when nitrogen monoxide is released?
it cools. it then reacts with more oxygen to form toxic nitrogen dioxide.
how can pollutants be removed from the air?
- particulates can settle on surfaces
- sulfur and nitrogen oxides react with water and oxygen to produce acid rain
- carbon dioxide - photosynthesis
- carbon dioxide - dissolves in rain water and oceans
Benefits of burning oil and gas instead of burning coal?
It makes less sulfur dioxide
How can power stations remove solid particulates?
using electrostatic filters
how can sulfur dioxide be removed from waste gases?
flue gas desulfurisation
What are the two ‘wet scrubbing’ methods used to remove sulfur dioxide from power station waste?
- using alkaline slurry of calcium oxide (line) and water to make calcium sulfate - can be sold as plaster
- using sea water, a natarul alkaline which absorbs sulfur dioxide
What are ways to reduce use of fossil fuels?
- using alternative energy resources
- improving building insulation
- reduce use of public transport
what is an alternative to fossil fuels
biofuels - made from plants. examples afe wood chips, palm oil and alcohol made from sugar
how can vehicles reduce air pollution?
- using cars less
- using cleaner fuels
- making public transport cheaper
What are catalytic converters and what do they do?
they contain platinum catalyst that allows pollutant gases to react with each other
what reaction (equation) happens inside a catalytic converter?
carbon monoxide + nitrogen monoxide > nitrogen + carbon monoxide
how long ago did earths atmosphere form?
4 billion years ago
