chemistry paper 2

organic chemistry

chemistry of the atmosphere

chemical anyalsis

using reasources

crude oil is a finite resource found in rocks its the remains of ancient biomass in particular plankton

crude oil is a mixture of hydrocarbons

most hydrocarbons in crude oil are alkanes which form a homologous series and only have single carbon-carbon bonds like ethane and butane

fractional distillation

crude oil can be separated using fractional distillation

the oil is evaporated and the hydrocarbon chains condense at different temperatures

fractions with low boiling points condense at the top for example petrol at 40 degrees were as fractions with high boiling points condense at the bottom for example residue which condenses at 340 degrees and is used for lubricating oil

crude oils ability to form different compounds makes it able to form fuels and feedstocks such as solvents

alkanes have different properties depending on their length a longer chains means that they are more viscose ,less flammable and have a higher boiling point

burning hydrocarbons

hydrocarbons can be burnt to release energy in this process carbon and hydrogen are oxidised to form co2 and water

cracking

shorter chai molecules are in higher demand than those with longer chains as they burn easier

shorter chain molecules can be created by cracking longer chain molecules

alkenes are different to alkanes as alkenes have a double covalent bond

the double covalent bound of alkenes gives them the ability to join to other molecules making them reactive

catalytic cracking

steam cracking:the alkanes are heated then vaporised at very high temperatures and then diluated with steam they are the reheated for a short amount of time.

uses of alkenes

polystyrene polyethene

Pure substance

Is a substance which doesn't contain any impurities

formulations

are mixtures which have been specifically measured quantities in order to give them a specific purpose eg paint

chromotography

Is a technique used which involves finding what elements a mixture Is made from and is done by the movement of a mobile phase through a stationary phase

rf value=distance travelled by substance/distance travelled by solvent

hydrogen test

squeeky pop

oxygen test

will relight a glowing splint

Test for chlorine

bleaches blue litmus paper

the earths atmosphere today is around 78 percent nitrogen 21 percent oxygen 1 percent noble gasses 0.03 percent co2

4 billion years ago volcanic activity released carbon dioxide methane ammonia and water vapour into the atmosphere the water vapour then condenses to form oceans

around 3 billion years ago carbon became locked up in sedimentary rocks as the oceans begin to form fosil fuels begin to be buried underground

around 2.7 billion years ago plants and algea began to form removing carbon dioxide to be removed a billion years ago this had led to enough oxygen for animals to evolve

the formation of carbonate rocks reduced the carbon dioxide concentration within the air

formation of oil and gass

dead sea creauters settle on the seabed

layers of sedimentary rock build up on top

the heat and pressure from these rocks along with the absence of oxygen mean that oil and gass are formed

the greenhouse effect

heat and light in waves try and escape the earths atmosphere

however a layer of gasses around the earth cause the heat to reflect back to earth

carbon footprint is the amount of green house gasses made in the production of something or within a chain of events

carbon dioxide,water vapour and carbon monoxide are created by the burning of gasses

sulfur dioxide cases acid rain which damages houses and buildings

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finite reasources are ones which will eventually run out

sustainable development is about preserving the world for tomorrow

water reasources

their are many water sources in Britain such as lakes,rivers and resevoirs

these types of water source can be purified by filtering and then being treated by chlorine or uv light

distilling seawater to boil off clean water is called desalination

a membrane filter can be used to filter out bacteria via reverse osmosis

nitrates used in farming and industrial waste can poullte water sources

steps of dealing with water waste sedimentation-filteration-chloranatin

carbon can be extracted by heating copper ich ores and displacing them with scrap iron or by electroylisis

phtoyming is were plants that absorb carbon are grown on copper rich soil and then burning the plants and collecting the ash which contains carbon

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