Fuels And Earth Science Flashcards
Define fractional distillation
Separating crude oil into simpler more useful mixtures
What do the fractional columns have?
Temperature gradients
How does the crude oil enter the fractionating columns?
Crude oil is heated, until most of it turns into gas
The gases then enter the fractionating columns
Name the crude oils in fractional distillation
Gases
Petrol
Kerosene
Diesel
Fuel oil
Bitumen
Use of gases
Heating and cooking
Use of petrol
Fuel for cars
Use of kerosene
Fuel for aircrafts
Use of diesel oil
Fuel for larger cars
Use of fuel oil
Fuel for large ships
Use of bitumen
Roofs and roads
What does each fraction have?
Alkanes
W/ similar boiling points
Shorter hydrocarbons boiling point
They have lower boiling point
Therefore, they turn to liquid and drains much later on (near the top)
Longer hydrocarbons boiling points
They have higher boiling points
They turn back into liquids and drain out early on (near the bottom)
FD : boiling point
Increases down the column
FD : flammability
Increases up the column
FD : viscosity
Increases down the column
Name 4 alkanes from the homologous series
Methane
Ethane
Propane
Butane
General formula for alkanes
CnH2n+2
Define homologous series
Family of molecules which have same general formula + similar chemical properties
The bigger the molecule (homologous series) …
Higher the boiling point
Define crude oil
Complex mixture of hydrocarbons
What does crude oil contain?
Molecules of carbon atoms, in chains or rings
Equation for complete combustion
Hydrocarbon + oxygen —> carbon dioxide + water
Equation for incomplete combustion
Hydrocarbon + oxygen —> carbon monoxide + water
Why is carbon monoxide produced instead of carbon dioxide, in incomplete combustion?
There is less oxygen than carbon dioxide
How is carbon monoxide dangerous?
No smell
Can’t see
No taste
How is carbon monoxide toxic?
Binds with haemoglobin in the blood, stopping red blood cells functioning properly
Soot on buildings
Name 3 pollutants
Carbon monoxide (incomplete combustion)
Sulphur dioxide (acid rain)
Nitrogen oxide
How does acid rain form?
1) fossil fuels burn, giving off carbon dioxide and sulphur dioxide
2) (sulphur dioxide comes form the sulphur impurities in fossil fuels)
3) sulphur mixes w/ clouds
Sulphuric acid =acid rain
Acid rain can cause…
Acidic lakes (killing fish)
Damage limestone buildings + statues
How does nitrogen oxide form?
Energy released from combustion forms a reaction between oxygen and nitrogen
Where can nitrogen oxide form?
Internal combustion of engines
Nitrogen oxide can cause…
Acid rain
Photochemical smog
Advantages of using hydrogen instead of petrol
- clean fuel
- no nasty waste products
- renewable source
Disadvantages of using hydrogen instead of petrol
- expensive
- hard to store and transport
Define cracking
Breaking large saturated hydrocarbons into smaller more useful ones
Define thermal decomposition
The breaking of covalent bonds though heat energy
What is creaking a form of?
Thermal decomposition
Why is cracking necessary?
There are higher demands for more useful fuels e.g petrol
Test for oxygen
Relight of a glowing splint
Describe earths early atmosphere
No oxygen present
Lots of carbon dioxide and water vapour
Describe phase 1 of the atmosphere
Volcanic activity formed earths early atmosphere
- releasing carbon dioxide and water vapour
- no oxygen
How did our oceans form?
Water vapour condensed
Describe phase 2 of our atmosphere
Early CO2 dissolved into the oceans
Nitrogen and oxygen levels increased
How did nitrogen increase in our atmosphere?
Ammonia + oxygen —> formed nitrogen
Nitrogen was released by denitrifying bacteria
Why have nitrogen levels increased so much?
It’s not reactive
How did oxygen increase in our atmosphere?
Plants evolved and photosynthesised (removing CO2)
% gradually increased
Define alkane
Saturated hydrocarbon
Define alkene
Unsaturated hydrocarbon
Describe the greenhouse effect
1) earth radiates heat
2) Infrared radiation absorbed by greenhouse gases
3) infrared reflected back to earths surface
4) infrared re-emitted into space
5) absorption and reflection keep earth warm
Name 3 greenhouse gases
Carbon dioxide
Water vapour
Methane
Name evidences of human activity causing climate change
Historical data
Correlation between CO2 concentration and fossil fuels
Why is historical data an inaccurate piece of evidence?
Less data taken over fewer locations
Methods of collecting data may be inaccurate
How can you estimate past climate?
Tree rings
Ice cores
What is the con of estimating past climate?
Can be less precise than instrumental sampling
What does the correlation between CO2 concentration and fossil fuels tell us?
Fossil fuels give out greenhouse gases, causing climate change
We need to reduce carbon emissions
What does today’s atmosphere consist of?
Nitrogen = 78%
Oxygen = 21%
Carbon dioxide = 0.04%
Argon = 0.96%
