Hydrocarbons Flashcards
As you move down the fraction tower from top to bottom how do the properties of fractions change? (5 things)
- they become LESS VOLATILE (they turn into a gas less readily)
- they become MORE VISCOUS (thick and sticky)
- they become LESS FLAMMABLE
- they become DARKER IN COLOUR
- ## they have HIGHER BOILING POINTS
What is crude oil a mixture of?
Crude oil is mainly a mixture of mainly hydrocarbons with differing amounts of carbons in them.
What is a use for refinery gas?
Bottled gas
What is a use for gasoline?
Fuel for cars
What is a use for naphtha?
Making chemicals
What is a use for kerosene?
Plane fuel
What is a use for diesel oil?
Fuel for cars, lorries and busses
What is a use for fuel oil?
Ship fuel
What is a use for the residue?
Roads (tarmac)
When pre-heating crude oil why is there and absence of air?
So all except the very highest boiling point substances are converted into gasses
Also to not set the crude oil on fire
What happens to the pre-heated crude oil within the refinery tube?
- The mixture is passed through the bottom of the fractioning tower
- There is no heat applied to the tower to let the molecules condense into liquids
- The gas rises up the tower, passing through trays
- When the molecules reach their boiling point they condense into liquids with similar sized molecules to form a mixture of similar sized molecules
- These mixtures are called fractions
What are alloys?
Alloys ate a MIXTURER of a METAL with one or more OTHER ELEMENTS, usually other metals.
E.g STEEL is an alloy of iron and carbon
What are some properties of products produce by fractioning.
- solvents
- lubricants
- polymers
- detergents
What would be the word equation for an ethane molocule going under compleate combustion?
Ethane + Sufficient Oxygen —-> Carbon dioxide + Water
What would be the word equation for ethane going under incomplete combustion?
Ethane + oxygen —-> carbon monoxide + water
C2H6 + 02 —-> CO + H2O
What is the difference between complete combustion and incomplete combustion chemical equation wise?
Complete combustion: CO2
Incomplete combustion: CO
What happenes when hydrocarbon fuels undergo combustion?
They hydrocarbon fuels release energy. During combustion, the carbon and hydrogen in the fuels are oxidised. The complete combustion of a hydrocarbon produces carbon dioxide and water.
The combustion of fuels is a major source of atmospheric pollution, what are some examples?
Coal, burning fossial fuels
What gasses are produced and put into the atmosphere when burning fossial fuels?
Carbon dioxide, water vapour, carbon monoxide, sulfer dioxide and oxides of nitrogen. Solid particals and unburnt hydrocarbons may also be released that form of particles.
What is an alkane?
They are SATURATED HYDROCARBONS with the general formula CnH2n+2
What is a hydrocarbon?
A molocule that is ONLY made up of hydrogen and carbon
What does saturated mean?
When the molocule only has single bonds
What is carbon monoxide?
Carbon monoxide is a toxic gas. It is colourless and oderless so it can pt be detected easily.
It is produced when a hydrocarbon undergoes incomplete combustion,
What is the effect of the atmospheric pollutants sulfer dioxide and oxides of nitrogen?
They cause respitory problems in humans and also cause acid rain
What is the effect of the atmospheric pollutant of particulates?
Particulates can cause global dimming and health problems for humans
What do green house gasses do?
They maintain the temperatures of Earth at the right temperature to support life.
Without the greenhouse effect the temp of the Earth would be similar to the moon (approximatly -18C)
At this temperature the water would freeze and therefore the world would become unliveable.
What is the greenhouse effect?
The process by which gasses in the atmosphere (greenhouse gasses) absorb and emit heat energy in the form of infra red radiation.
This keeps the Earths temperature constant around 13C
What human activities increase the rate of production of methane and carbon dioxide (green house gasses)
Carbon dioxide: deforestation, burning of fossial fuels
Methane: over agruculting with cows, decomposition of food
What are four potential effects of global climate change
Rising sea levels (due to water expanding when hot)
More extreame weather
Droughts
Crop faliure
What is the process in which larger alkanes are broken to form smaller alkanes and alkenes!
Catalitic cracking
What are the three types of catalitic cracking?
Thermal: (heat to 600C - 700C) in the abscence of air
Catalytic: (heat to 600C - 700C) with a catalyst in the abscence of air
Steam: (heat to 600C - 700C) with steam in the abscence of air
What is bromine water used to test for?
Alkenes
What colour change does bromine water undergo when reacting with an alkene?
Orange —-> Colourless
Why is catalytic cracking useful?
There is high demand for fuels with smaller molecules therefore making cracking importent. It also provides us with alkenes which can be used to make polymers.
What is a polymer?
Polymers are large chains of monomers. They are very large and very strong. This is due to the polymer molocules being linked by strong covalent bonds.
The intermolecular forces between polymer molecules are realitvly strong so they are solid at room temperature
What is the enviromental impact of extracting crude oil?
Damage of ecosystems
Risk of an oil spillage
What are the envromental impacts of processing and storing crude oil
Refineries requires habitats to be detroyed
The construction od refineries requires lots of energy, usually from fossial fuels
What are some environmental impacts of using crude oil as a fuel?
Many fuel are burnt through complete combustion which produces carbon dioxide
This increases the amount of heat energy trapped in our atmosphere, therefore increasing the rate of global warming
What are some of the downsides of crude oil
Its a non renewable, finite (one day it will run out) reasource
What are some of the positives of crude oil
Its used to make: Medicin Pesticides Herbicides Fuels Plastics
What is a carbon footprint?
The total amount of carbon dioxide andother green house gasses emitted over the full life cycle of a product, service or event.
How could you reduce your carbon footprint?
Use clean energy
Dont waste food
Eat less meat
Dont waste electricity
What do you use to test for water?
Colbat (II) Chloride paper (turns blue to pink)
How does the green house effect work and how does it warm the Earth?
~ The sun RELEASES ENERGY in the form of SOLAR RADIATION
~ When this reaches the Earth roughly 30% is relected by the atmosphere back into space
~ The remaining 70% PASSES THROUGH THE ATMOSPHERE, which is transparent to most of the radiation, and reaches the Earths surface
~ 20% of the energy is used in the water cycle
~ 50% of the energy is ABSORBED BY THE LAND AND SEA
~ Some of the THERMAL ENERGY is RE-EMITTD AS INFRA RED RADIATION.
~ Some of this INFRA RED radiation ESCAPES into SPACE
~ A percentage of the IR RADIATION is absorbed by GREENHOUSE GASSES
~ The GREENHOUSE GASSES RE EMITT the IR in different directions
~ this TRAPS the SOLAR ENERGY withing the ATMOSPHERE, keeping our planet at 13C
