Organic 1 - 4.5 Flashcards
What is crude oil made up of?
Crude oil is a mixture of hydrocarbons
What makes up a hydrocarbon?
a hydrocarbon compound is made up of hydrogen and carbon ONLY
What happens as the fractions boiling point increases?
- the fractions get darker in colour
- the fractions get more viscous
What are the important fractions?
Refinery gases
Gasoline
Kerosene
Diesel
Fuel oil
Bitumen
What is the use of refinery gases?
FUEL for home cooking
What is the use of gasoline?
FUEL for cars
What is the use of kerosene?
FUEL for aircraft
What is the use of diesel?
FUEL for trains
What is the use of fuel oil?
FUEL for ships
What is the use of bitumen?
making road
NOT FUEL
What happens during fractional distillation?
Each of the fractions is separated from crude oil by fractional distillation.
The fractional distillation of crude oil is done industrially on a large scale.
The fractionating column is hotter at the bottom and colder at the top.
How does fractional distillation work?
- Crude oil is heated/vapourised
- The vapour passes into/rises up the fractioning column
- Different vapours condense at different heights due to their different boiling points
- Similar vapours condense together as a fraction.
What is the general formula for alkanes?
CnH2n+2
What is meant by the term homologous series?
A family of molecules which have:
similar chemical reactions
trends in physical properties
the same general formula
What is meant by the term functional group?
What is meant by the term isomerism?
Isomers are molecules with the same molecular formula but different structural formulae
What are the products of complete combustion of hydrocarbons?
carbon dioxide
water
What are the products of incomplete combustion of hydrocarbons?
Carbon monoxide
Soot - causes lung disease
What type of reaction occurs with alkanes when they react with halogens - substitution or addition?
substitution - because it will swap
the reaction requires UV light - because the alkane is pretty unreactive
Why is carbon monoxide poisonous?
a toxic gas that lowers the oxygen carrying capacity of blood
What pollutants does the combustion of alkanes as fuels release in the atmosphere?
Carbon dioxide - forms directly from the combustion of the alkane fuel.
It is a greenhouse gas that traps heat in the atmosphere and causes climate change
Nitrogen oxides - form when nitrogen from the air combusts.
Usually nitrogen doesn’t combust but car engines are really, really hot.
They dissolve in rainwater to form acid rain, which corrodes structures and is harmful
to plant and aquatic life.
Sulphur dioxide - This forms when sulphur impurities in the fuel combust.
Like nitrogen oxides, it also dissolves in rainwater to form acid rain.
Why are alkanes classified as saturated carbons?
because they do NOT have a double carbon bond
What is the general formula for alkenes?
CnH2n
Why are alkenes classified as unsaturated hydrocarbons?
They DO contain a double carbon bond
What happens when alkenes react with bromine?
break the double carbon bond and add the bromine atoms in
addition reaction
works with pure bromine liquid or bromine water
mixture turns ORANGE to COLOURLESS - because the bromine is used up in the reaction
this reaction is used as a test for the double carbon bond in unsaturated compounds
What is an addition polymer?
an addition polymer forms when molecules with a double carbon bond add into chains
What are the problems with the disposal of addition polymers?
Addition polymers are inert, which means they’re chemically very unreactive.
This means they don’t break down very easily
What are the only options for disposal of an unwanted addition polymer?
Reuse it, or give it to someone else who will use it
Recycle it, which allows it to be reshaped for another use.
Incinerate it, and use the energy released to generate electricity.
Chuck it onto landfill, and hope it goes away
