CHEMISTRY - Crude Oil, Fuels and Organic Chemistry Flashcards
what is crude oil
a fossil fuel formed over millions of years from the remains of dead marine organisms. it is non renewable and a finite source
what is fractional distilation
a process that is used to separate pure liquid from a mixture of liquids with different boiling points.
how are the two liquids separated in fractional distillation
separated based on different boiling points
how is crude oil separated using fractional distillation.
-crude oil is pumped in as vapour at the bottom of the fractionating column
-the column gets cooler towards the top
-as vapours rise they re-condense back to liquids at different heights, and they are pumped out.
-each liquid is called a fraction
-a fraction is a mixture of hydrocarbons of similar size, with similar boiling points.
what are the main uses for liquid petroleum gas
gas for cookers
what is the main use of petrol
fuel for cars
what is the main use of paraffin/kerosene
fuel for jets
what is the main use of diesel
fuel for cars/heavy vehicles
main use of heating oil
fuel for central heating systems
main use of fuel oil
fuel for ships
main use of bitumen
‘tar’ for surfacing roads
what is a hydro carbon
compound made with only hydrogen and carbon
what are the political issues of crude oil exploitation
its a finite source so our own supplies will eventually run out. then the uk will depend on politically unstable countries. supplies will be scarce.
what are the environmental issues of crude oil exploitation
crude oil can be spilled during transport by ship, causing oil slicks that damage beaches and wildlife.
why is crude oil a non renewable source
it is used up faster than its formed.
what is the equation for complete combustion
hydrocarbon + oxygen –> carbon dioxide + water
what substance is cobalt chloride paper used to test for
water vapour
describe the colour change seen when the products of complete combustion are passed over cobalt chloride paper
goes from blue to purple
what substance is limewater used to test for
CO2
carbon dioxide
describe what is observed when the products of complete combustion are bubbled through limewater
goes milky
how is hydrogen used as a rocket fuel
oxygen will violently react with pure hydrogen, the hydrogen burns with the oxygen to form water and heat.
2 H2 + O2 –> 2 H2O + heat energy
what are 2 advantages and disadvantages for using hydrogen as a fuel
+ NO CO2 is produced
+ Renewable
– Explosive
– Hard to store
what do we do to make a fair test for a calorimeter test
-heat same volume of water
-use same size copper can
what material is the calorimeter made of, and why?
copper - it conducts heat better, transfers heat energy to water quickly
why isn’t all of the heat energy that is released, transferred to the water
(in terms of calorimeter practical???)
the energy is lost to the surroundings at points throughout the experiment
what is one way of improving the reliability of the calorimeter experiment
add an insulator to trap heat
for ethanol to burn as a fuel, 3 things are required, what are they? and how can it be represented
-heat
-oxygen
-fuel
can be presented through the fire triangle
what is the key to putting out a fire?
to remove one of the 3 components of a fire triangle
-oxygen
-heat
-fuel
how would each component of the fire triangle be removed from a fire
-heat is removed with cold water
-oxygen is removed by fire blanket or CO2
-Fuel from fire is unlikely to be removed. but could cut down trees during a forest fire.
what type of fire should water never be used to extinguish
electrical fire or oil fire
what is cracking and what 2 things does it require
a reaction carried out to convert long chain hydrocarbons to short chain hydrocarbons.
-requires a high temperature
-requires a catalyst
what are 2 advantages of cracking
-helps an oil refinery to convert long alkanes (which is low demand) to shorter alkanes (which is high demand)
-produces alkenes also, which can be used to make polymers (aka plastic)
what are the two types of hydrocarbon
alkanes and alkenes
how is the formula for an alkane set up
Cn+H2n + 2
eg. C5 + H12
2n so 5x2=10 and then plus 2 = 12
the numbers are meant to be small btw
how many bonds can a carbon have, and how many can a hydrogen have?
a carbon can have 4 bonds to other atoms
hydrogen can only form 1 bond
what is the name given to the molecules with the same molecular formula but different structural formula?
isomers
how is the general formula for alkenes set up
C12+H24
numbers meant to be small
what are the names of each carbon atom molecule thingy? (Alcohols)
meth - 1 carbon atom
eth - 2 carbon atoms
prop - 3 carbon atoms
but - 4 carbon atoms
(so its like propane for an alkane and propene for and alkene)
you need to remember these 4 names
what are the 3 types of addition reactions
type 1 - hydrogenation- hydrogen
type 2 - bromination - bromine
type 3 - hydration - water
Alkanes are saturated, what does this mean?
meaning that it contains the greatest possible number of atoms
and it has no double bonds because of this
Alkenes are unsaturated, what does this mean?
meaning that it has a double bond between two carbon molecules, (like this C=C) meaning that it doesnt contain the greatest possible number of atoms
this double bond can be broken into a single bond (like this C-C) and when this happens, other atoms are able to bond to the other bond that just broke, which then means its now saturated.
what do you observe from
bromine + alkane reaction
bromine + alkene reaction
bromine + alkane = no reaction because alkanes are saturated
bromine + alkene = turns from orange/brown to colorless
what are polymers
long chain molecules made by adding together alkenes ( the alkenes are called monomers)
what are 6 properties of polymers
flexible
strong
thermal and electrical insulators
resistant to corrosion
low density
dont rot
what are 4 uses of polymers
polyethene - plastic bottles
polypropene - ropes
polyvinylchloride - drain pipes
polytetrafluoroethene - non-stick pans
polymers are non biodegradable, so they cant be decomposed by bacteria and take centuries to rot
what are 4 issues with this
-landfill sites get filled quickly, wasting valuable land
-burning plastics makes toxic gases
-valuable plastics are wasted by dumping or burning
-time consuming to sort out different polymers, so recycling is difficult
of the 3 alcohols, which one can form isomers?
propanol
propan-1ol and propan-2-ol
how can ethanol be made
through fermentation
or
reacting ethene with water (steam)
ethane + water = ethanol
why doesnt methene exist?
because for alkenes, each alkene has one double bond, and methene only has one carbon, it doesnt have another carbon to double bond with, so it doesn’t exist.
