organics 1 Flashcards
what is crude oil
a mixture of hydrocarbons
what is a hydrocarbon
a compound containing only hydrogen and carbon
what happens to the boiling point if the chain is longer and why
longer chain = higher boiling point
this is because a longer chain has more IMF’s so more energy is needed to overcome all the forces
what happens to the boiling point if the chain is shorter and why
shorter chain = lower boiling point
this is because a shorter chain has less IMF’s so less energy is needed to overcome all the forces.
how do we separate crude oil?
fractional distillation
what is the name of the fraction of crude oil with the lowest boiling point and is also the smallest molecule?
refinery gas
what is the name of the fraction with the highest boiling point which also contains the largest molecules?
bitumen
name each fraction in order
refinery gas
gasoline
kerosene
diesel
fuel oil
bitumen
what is the use of refinery gas
home heating
what is the use of gasoline
car fuel
what is the use of kerosene
plane fuel
what is the use of diesel
lorry fuel
what is the use of fuel oil
ship fuel
what is the use of bitumen
road tarmac
what is fractional distillation and how does it work
crude oil is a mixture of many different things, fractional distillation separates them depending on their properties. it dies this by separating molecules with similar length chains which therefore have similar properties.
what are the products of complete combustion of crude oil
CO2 and H2O
what are the products of incomplete combustion of crude oil
CO and H2O
carbon monoxide is a toxic gas
when does incomplete combustion of crude oil
when there is not enough oxygen
why is CO2 a pollutant
its a greenhouse gas so it results in the enhanced greenhouse effect which leads to global warming
why is CO (carbon monoxide) dangerous
it binds to haemoglobin which means you can carry less oxygen so you cant respire.
why can N2 and O2 be dangerous
when at high temperatures they form NO (nitrogen oxide) which is a poisonous gas and when combined with water forms acid rain
what is an impurity in crude oil
S (sulfur)
why is sulfur dangerous
when combined with oxygen, sulfur forms sulfur dioxide which when combined with water forms acid rain
why is acid rain bad
damages ecosystems, buildings, infrastructure, dangerous for wildlife
what is cracking
the process of heating up longer chains to break them into smaller chains
why do we use cracking
to make longer chains into smaller chains which are in higher demand
why are smaller chains in higher demand
because they are more useful
what is the catalyst used in cracking
aluminium oxide (Al2O3)
what is the temperature needed to crack chains
600C
what is the difference between alkanes and alkenes
alkanes are hydrocarbons with only single bonds and alkenes are hydrocarbons with one double C=C bond.
alkanes are saturated, alkenes are unsaturated.
What is the general formula for alkanes
CnH2n+2
Name each of the first 6 alkanes in the homologous series in order of increasing number of carbon atoms
Methane
Ethane
Propane
Butane
Pentane
Hexane
What is the formula for methane
CH4
What is the formula for ethane
C2H6
What is the formula for propane
C3H8
What is the formula for Butane
C4H10
What is the formula for pentane
C5H12
What is the formula for hexane
C6H14
What is an isomer
A molecule with the same molecular formula but a different structural and displayed formula
Why are alkanes unreactive
Because they have a very high activation energy as c-c bonds and C-H bonds are very strong. Same reason as for crude oil.
What is an alkene
A hydrocarbon containing one C=C double bond. Unsaturated.
What is the general formula for an alkene
CnH2n
Are alkenes more or less reactive than alkanes and why
Alkenes are much more reactive than alkanes because they are unsaturated. The double bond in an alkene can easily open to allow two more atoms to join and leave a single bond between the carbons.
What is the test for alkenes
Add bromine water, if it turns from orange to colourless then its and alkene. If remains orange its an alkane.