4.5 Organic 1 Flashcards
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:}~:’[p[#k#jlh;g’what is crude oil
A mixture of hydrocarbons
what are hydrocarbons
A compound made up of only hydrogen and Carbon only
what is the name of the process use to separate pure water from sea water
Simple Distillation
Identify the method used to separate the dyes in a food colouring
Chromatography
Identify the method use to obtain ethanol from a mixture of ethanol and water
Fractional Distillation
Name the process used to separate potassium Nitrate from potassium nitrate solution
Crystallisation
what is each fraction of crude oil
A mixture of similar Hydrocarbons with similar boiling points
Name the 6 Fractions in crude oil
Refinery
Gasoline
Kerosene
Diesel
Fuel oil
Bitumen
what is the use of each Fraction
Refinery- Cooking
Gasoline- Cars
Kerosene- Aircraft
Diesel- Trains
Fuel oil- Ships
Bitumen- Roads
what happens as you go down the fraction list
the boiling point increases
Molecular mass increases
The colour gets darker down the list
Viscosity (thickness) increases down the list
How does Fractional Distillation Work
- Heated Crude oil vapours enter the column
- Vapours rise until they reach their boiling point, when they condense.
- Different Vapours condense at different heights due to their different boiling points
- Similar vapours condense together as a fraction
What are fractions
Are mixtures containing the hydrocarbons that boil in a particular temperature range.
what are Alkanes
Alkanes are hydrocarbons that fit the general formula CnH2n+2
what is the general formula for Alkanes
CnH2n+2
what bonds join the c and H atoms
covalent bonds
what does the name of each alkane show
the start shows how many carbon atoms it has
The end of the names is ane- which shows it is an alkane
what is the molecular formula for Methane
CH4
what is the molecular formula for Ethane
C2H6
What is the molecular formula for Propane
C3H8
what is the Molecular formula for Butane
C4H10
What is the molecular formula for pentane
C5H12
alkanes are what
Homologous series
Because alkanes are homologous series what does this mean
Similar chemical reactions
trends in physical properties (boiling points, viscosity, colour)
The same general formula
What is the definition of Isomers
Isomers are molecules with the same molecular formula but different structural formulae
what are two types of combustion alkanes have
complete and incomplete
what causes the outcome of the combustion
the oxygen available
explain complete combustion
This occurs when there is excess oxygen
it produces co2, H20
what is the equation for alkane complete combustion
Alkane + oxygen—–> Carbon dioxide + water
explain incomplete combustion
This occurs when there isn’t enough oxygen
instead of producing c02 this produces a nasty mixture of
- carbon monoxide
- soot (c)
releases less energy so it makes the alkane less useful.
what are the two toxic gases incomplete combustion releases and what is the negative effect of them.
carbon monoxide- a Toxic gas which lowers oxygen- carrying capacity in blood (irreversible)
soot- which causes lung disease
what are the three pollutants alkanes combustion releases into the atmosphere
Carbon dioxide (co2)
Nitrogen oxides (NOx)
Sulphur dioxide (SO2)
what is the effect of carbon dioxide pollutants
this forms directly from the combustion of the alkane fuel
it is a greenhouse gas that traps heat in the atmosphere and causes climate change
what is the effect of Nitrogen oxide pollutants
family of compounds from when nitrogen from air combust
nitrogen doesn’t combust but car engines are really, really hot
the nitrogen compounds dissolve in rain water to form acid rain
what is the effect of acid rain
corrodes structures and is harmful to plant and aquatic , soil erosion
what is the effect of Sulphur dioxide pollutants
like nitrogen it dissolves in rain water causing acid rain.
what happens with alkanes when they react with halogens
- substitution
- reaction requires UV light
why is the reaction called substitution
because the H swaps with the Halogen
why does a halogen and alkane reaction require UV light
Because the alkane is pretty unreactive
produces energy
what is cracking
cracking breaks down longer alkanes into smaller, more useful ones
- crude oil contains longer alkanes
- shorter alkanes are more useful
what the conditions needed for Cracking
Temperature 650c
catalyst- aluminium oxide (Al2 O3)
Are alkanes Saturated or unsaturated
Saturated because they don’t have c=c double bonds
Are alkenes saturated or unsaturated
Unsaturated as they have a C=C Double bond
