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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