alkanes and halogenoalkanes

Question 1

what is complete combustion?

Answer 1

burning alkanes with plenty of oxygen to get carbon dioxide and water

Question 2

what is incomplete combustion?

Answer 2

when there’s not enough oxygen so you produce particulate carbon (soot) and carbon monoxide

Question 3

what are some problems of CO2 ?

Answer 3

it is formed from the complete combustion of fuels containing C. It id a greenhouse gas

Question 3

what are some problems with CO?

Answer 3

it is formed from the incomplete combustion of fuels containing C. it is toxic

Question 4

what are some problems of C?

Answer 4

it is formed from the incomplete combustion of fuels containing C. it blackens buildings, can cause respiratory problems and global dimming

Question 5

what are some problems of H2o?

Answer 5

it is formed from the combustion of fuels containing H and it is not a problem

Question 6

what are some problems of SO2?

Answer 6

it is formed from the combustion of fuels containing S. can cause acid rain

Question 7

what are some problems of nitrogen oxides?

Answer 7

it is formed from a reaction with N2 from the air with O2 at very high temperatures

Question 8

what are some problems with unburned hydrocarbons?

Answer 8

it is for ed when some of the fuel doesn’t actually burn. it wastes fuel

Question 9

describe the formation of SO2

Answer 9

sulfur containing impurities are found in petroleum fractions which produces SO2 when burnt –> produces acid rain
SO2 can be removed from the waste gases from furnaces by FLUE GAS DESULFURISATION
gases pass through a scrubber containing CALCIUM OXIDE or CALCIUM CARBONATE which reacts with the sulfur dioxide

Question 10

describe what happens in the internal combustion engine

Answer 10

petrol is used in the internal combustion engine where alkanes are vaporised and combusted with the air. Catalytic converters remove CO, nitrogen oxides and unburned hydrocarbons from the exhaust gases turning them into CO2, N2 and H2O
catalytic converters have a large surface area because converters have a ceramic honeycomb coated with a thin layer of catalyst wedding

Question 11

describe the greenhouse effect

Answer 11

• EM radiation is emitted from the sun
• the earth re-emits infrared radiation
• the C=O bonds in CO2 absorbs the infrared
• not all the infrared escapes from the atmosphere
• energy is transferred to other molecules by collisions which increases their kinetic energy so increases global temperature