C9- Crude oil and fuels Flashcards
Crude oil def?
How is it extracted?
Made of what?
Source of what?
A mixture made from remains of biomass from microscopic organisms (algae and plankton)
Drilling
Different hydrocarbons
Petrol and diesel fuel
2 living organisms that made up crude oil
Algae and plankton
How was crude oil made?
Remains from algae and plankton buried under layers of rock, creating high pressure and temperature, lack of oxygen
Hydrocarbon
A compound that contains only hydrogen and carbon atoms
How to make crude oil useful?
Fractional distillation to separate the substances
What are alkanes?
What mainly consists of alkanes?
Saturated hydrocarbons, contain maximum number of hydrogen atoms
Crude oil
What do straight lines in alkanes represent?
General formula for alkane molecules?
Single covalent bonds
CnH 2n+2
First 6 alkanes?
Methane
Ethane
Propane
Butane
Pentane
Hexane
Alkane state at room temp depends on..?
Why?
Depends on intermolecular forces
Bigger forces, higher boiling point
Smaller chains of hydrocarbons
Boiling point?
Volatility?
Viscosity?
Flammability?
Lower, weak intermolecular forces, need less energy to overcome
High volatility- turns into gas easily
Low viscosity, very runny
Highly flammable
Larger chains of hydrocarbons?
Boiling point?
Volatility?
Viscosity?
Flammability?
Higher, stronger intermolecular forces, more energy to overcome
Low volatility
High viscosity
Lower flammability
How is crude oil separated?
Into what and its def?
Fractional distillation
Fractions- groups which have similar boiling points
Describe the process of fractional distillation of crude oil
Crude oil heated at around 400 oc, fed into fractionating column as vapour, some is drawn off as a liquid at bottom
Vapours rise until they reach their boiling point, then cool and condense
These fractions collected as a liquid
Hydrocarbons with lowest boiling points move to top of column where coolest
What are the products of complete combustion of a hydrocarbon?
What does incomplete combustion of a hydrocarbon produce?
Carbon dioxide and water
Carbon monoxide
How to test the products of complete combustion of a hydrocarbon?
Gas produced from flame, travels through ice bath where it condenses due to ice and the water turns blue cobalt chloride paper pink.
Gas then bubbled through limewater, where carbon dioxide turns it cloudy
Complete combustion…
Oxygen?
More likely in?
H atoms become?
C atoms become?
Products cause?
Enough oxygen
Small alkanes and blue bunsen flame
Water
Carbon dioxide
Contributes to climate change
Incomplete combustion
Oxygen?
More likely in?
H atoms become?
C atoms become?
Products cause?
Not enough oxygen
Large alkanes and yellow bunsen flame
Water
Carbon monoxide or carbon (soot)
Carbon monoxide is toxic, carbon causes lung disease
How to work out… in combustion of hydrocarbon equation?
CO2 atoms?
H2O atoms?
O2 atoms?
CO2= number of C atoms in hydrocarbon
H2O= CO2 +1
O2= CO2 + (1/2 x H2O)
What is cracking?
What type of reaction is it?
Process of breaking down long hydrocarbons into shorter more useful ones like, alkanes and alkenes
Thermal decomposition
General formula for alkenes?
How to tell alkenes?
CnH2n
Unsaturated, contains double bond between C atoms
How to test for an unsaturated hydrocarbon?
Bromine solution will turn from orange to colourless
Difference between thermal and catalytic cracking
Thermal- high temp and pressure
Catalytic- low temp and pressure
Thermal cracking
Takes place in?
Temp?
Pressure?
Catalyst?
Industry
450-750oc
70 atm
None
Catalytic cracking industry?
Temp?
Pressure?
Catalyst?
500oc
1atm
Zeolites
Catalytic cracking laboratory?
Temp?
Pressure?
Catalyst?
Bunsen flame
1 atm
Broken crockery, pumice stone
