the atmosphere - pollutants from fuels

Question 1

what do fuels release?

Answer 1

energy when they are combusted (burned).
examples: coal + hydrocarbons

Question 2

uses of coal? uses of hydrocarbons?

Answer 2

coal: generate electricity in power stations
hydrocarbons: those found in petroleum and diesel are used to power vehicles such as cars

Question 3

what do most fuels contain? including coal + hydrocarbons

Answer 3

elements of carbon and hydrogen

Question 4

what happens when we burn fuels such as coal and hydrocarbons?

Answer 4

carbon + hydrogen atoms react with oxygen in the air (oxidised)

Question 5

where is methane found? use?

Answer 5

natural gas + used to heat homes

Question 6

methan + oxygen ->
CH4 + 2O2

explain reaction?

Answer 6

carbon dioxide + water
CO2 + 2H2O

carbon atom in methane has been oxidised to form gas carbon dioxide. the carbon dioxide contributes to climate change
hydrogen atoms oxidised to form water vapour
this is complete combustion as carbon dioxide produced

Question 7

what happens to combustion if methane if oxygen levels are reduced?

Answer 7

carbon monoxide is produced instead of carbon dioxide

Question 8

what is carbon monoxide?

Answer 8

a toxic gas which is colourless and has no smell. in homes people have carbon monoxide detectors

Question 9

what does some fuels such as coal contain? what happens when it is burnt?

Answer 9

an element of sulfur. when burned, sulfur atoms are oxidised and produce a gas of sulfur dioxide
S + O2 -> SO2
sulfuric + oxygen -> sulfur dioxide

Question 10

when are oxides of nitrogen produced?

Answer 10

inside engines for example in cars. The high temperatures cause nitrogen + oxygen from the air to react producing a range of different molecules. scientists call them all oxides of nitrogen (NOx)
N2+O2->NOx

Question 11

effects of sulfur dioxide and oxides of nitrogen

Answer 11

• cause breathing problems in humans
• dissolve in rainwater to form acid rain. this can damage trees and corrode buildings made from limestone

Question 12

final pollutant produced from burning fuels. what is produced from a truck burning diesel?

Answer 12

black clouds of particles of carbon (soot) + unburned hydrocarbons. these are called particulates

Question 13

what are particulates?

Answer 13

unburned hydrocarbons and particles of carbon (soot)

Question 14

effects of particulates?

Answer 14

• damage human health eg increase risk of heart disease and lung disease
• reduce amount of energy from sun that reaches earths surface. this is called global dimming.possible that global dimming affects rainfall patterns