Crude oil Flashcards
what is the homologous series (1 mark)
a ‘family’ of organic compounds with the same functional group and similar chemical properties
what are hydrocarbons (1 mark)
compounds containing only hydrogen and carbon atoms
what is viscosity? (1 mark)
the thickness of a fluid
what is flamibility? (1 mark)
how easily a hydrocarbon combusts (burns)
What are the properties of hydrocarbons? (4 marks)
viscosity
- long chain hydrocarbons are extremely viscous
flammability
- short chain hydrocarbons are extremely flammable
boiling point
- short chain hydrocarbons have a low boiling point
Volatility
- short chain hydrocarbons have a higher volatility
general formula of alkanes
CnH2n+2
general formula of alkenes
CnH2n
What are the features of alkanes? (4 marks)
the form a homologous series
general formula
they are hydrocarbons
they are saturated
Explain how crude oil is formed (4 marks)
Crude oil is formed over millions of years from the remains of plankton, which were buried in the mud.
The mud stopped them from rotting away.
The oil from the dead animals got stuck under a layer of caprock, which will not let them through.
Why are alkanes ‘saturated’? (1 mark)
there are only single covalent bonds between carbon atoms
Explain the process of fractional distillation (4 marks)
Oil is heated to about 450°C and pumped into the bottom of a tall tower called a fractionating column, where it vaporizes.
The column is hotter at the bottom and cooler at the top. As the vaporized oil rises, it cools and condenses.
The heavy fractions (containing large molecules) have a high boiling point and condense near the bottom of the column.
The lighter fractions (containing small molecules) have a low boiling point and condense near the top of the column
What is the order fractions are distilled in the fractionating column?
Liquid Petroleum Gas (LPG) - Short Chain Hydrocarbons
Petrol
Kerosene
Diesel Oil
Heavy Fuel Oil
Bitumen - Long chain hydrocarbons
What is a formulation? (1 mark)
A formulation is a mixture that is a useful product (e.g. toothpaste)
What is complete combustion? (2 marks)
This is when oxygen is unlimited, causing the reaction to produce carbon dioxide and water
What is the cause, problem and solution for the pollutant ‘carbon monoxide’?
CARBON MONOXIDE - formed due to incomplete combustion of fuels containing carbon atoms; can lead to carbon monoxide poisoning; can be reduced by providing sufficient oxygen during combustion