fuels and hydrocarbons Flashcards
What are non-renewable resources?
Non-renewable resources are resources that have a certain supply which will run out eventually.
What are hydrocarbons?
Hydrocarbons are molecules made of hydrogen and carbon atoms.
What is crude oil?
Crude oil is a non-renewable resource that is a mixture of different compounds that aren’t chemically combined, which is made from phytoplankton.
What are long chain hydrocarbons?
Long chain hydrocarbons are hydrocarbons that have a lot of carbon atoms.
What are short chain hydrocarbons?
Short chain hydrocarbons are hydrocarbons that have few carbon atoms.
What is fractional distillation?
Fractional distillation is when crude oil is separated into fractions that have like numbers of carbon atoms.
What are fractions?
Fractions are groups of hydrocarbons.
What are plankton?
Plankton are tiny plants and animals from the sea.
What is feedstock?
Feedstock is a material used in the industrial process.
What is a homologous series?
A homologous series is a series of compounds with generally the same formula.
What is the composition of the Earth’s atmosphere?
Currently there is 21% of oxygen, 78% of nitrogen and 1% of other gases, like carbon.
What is photosynthesis?
Photosynthesis takes in carbon and makes oxygen.
What are fossil fuels?
Fossil fuels are non-renewable resources that contain carbon.
How is coal formed?
Coal is created from the remnants of trees that do not decompose in marshy wetlands due to lack of oxygen or acidic conditions.
What prevents decomposition of plant remains?
Lack of oxygen or acidic conditions prevent bacteria from causing decomposition.
How is coal formed from plant remains?
After time, sediment covers the plant remains and they are then compressed by high pressure and temperature.
How is crude oil formed?
When plankton die, they settle in mud on the sea bed and do not decompose if there is a lack of oxygen; over time, heat and pressure turn them into crude oil.
What is natural gas primarily composed of?
Natural gas is mainly the hydrocarbon of methane.
Where is natural gas found?
Natural gas is found by deposits of oil.
What is the main use of crude oil?
Crude oil is used to make fuels and other chemicals.
What are hydrocarbons in crude oil?
Hydrocarbons take up the majority of compounds in crude oil and have different sizes, leading to different properties.
What is the structure of methane?
Methane contains one carbon atom and four hydrogen atoms covalently bonded together.
What are alkanes?
Hydrocarbons like methane and ethane are alkanes.
What is the structure of ethene?
Ethene contains 2 carbon atoms and 6 hydrogen atoms.
How does fractional distillation work?
Fractional distillation separates hydrocarbons using their different boiling points.
What happens during evaporation in fractional distillation?
Heat the crude oil to evaporate it; crude oil vapour is put into a fractional column located at the bottom and it rises upwards.
What happens during condensation in fractional distillation?
Long chain hydrocarbons condense at the bottom, where the temperature is highest, and are collected as liquids; short chain hydrocarbons pass through the top, where the temperature is lower.
What happens to the fractions collected from fractional distillation?
The fractions are collected and made into products, such as fuel or feedstock for detergents and lubricants.
What are the functions of different fractions from fractional distillation?
Kerosene is used for aircraft, diesel oil for cars and trains, fuel oil for large ships and power stations, petrol for cars, gases for domestic heating and cooking, and bitumen for surfacing roads and roofs.
What are the characteristics of members of a homologous series?
Members of the homologous series can have similar chemical properties but different physical properties.
What is the general formula for a homologous series?
The homologous series have the same general formula and neighbouring compounds have a difference of CH2.
what two things effect the properties of hydrocarbons
- the size of the hydrocarbons
- the usefulness of the hydrocarbons
what do hydrocarbons that have longer chains have
- higher melting point
- higher viscosity
3.this means they are thicker,flow easily and are less flamma ble
what do shorter hydocarbon chains have
higher flammability,lower melting point and lower viscosity
compared with short hydrocarbon chains, what do longer hydrocarbon chains have
higher melting point, higher viscosity and lower flammability
what is cracking
the process that breaaks down logn chain hydrocarbons into shorter chain molecules that are more useful
what is cracking an example of
a thermal decomposition reaction
what two ways can cracking be done
1.catalyic cracking
2. steam cracking
what is catalyic cracking
when vapouriesed heavy hydrocarbons are passewd over the top of a heated catalyst. alkanes and alkenes are produced from this reaction
what is steam cracking
when vapourised heavy hydrocarbons are mixed in steam in a high temperature environment. the products are alkanes and alkenes
what does the equation for the combustion of hydrocarbon depend on
the amount of oxygen is avaliable
what happens if alkanes are burned without enough oxygen
carbon monoxide is created - 2C + 02 -> 2C02
what are the properties of carbon monoxide
- colourless
- toxic
- odourless
what is the problem with incomplete combustion
- incomplete combustion produces soot
- soot can build up in applaicnes and cause problems
3.this happens in cars and any items that use carbon as fuel
what does the combustion of hydrocarbon with a good air supply involve
- energy release
2, the oxidation of carbon and hydrogen to create carbon dioxide and water
what is the equation for the complete combustion of ethane
2C2H6 + 7O2 → 4CO2 + 6H2O
what do fossil fuels contain
hydrocarbons and impurities
what is sulfur
an impurity that is presnt in all fossil fuels
what happens when sulfur oxidies
it burns and produces the toxic gas sulfer dixoide
what does the toxic gas of sulfur dioxide do if inhaled
sulfur dioxide can cause respiration problems
what does the sulfur dioxide form with water
sulfuric acid
what does acid rain cause
- steel corrossion
- weathing of buildings
- death of inseects
what is sulfric acid
a major component of acid rain
what happens when hydrocarbond burn in confined space
- the high temp can cause nitrogen and oxygen to react
- this leads to the formation of toxic nitrogen oxides
what can hydrogen fuel cells be alternatives for
petrol as fuel for cars
what are the advantages of using hydrogen instead of petrol
1.hydrogen fuel cells use hydrogen and oxygen and the only waste product is water
2.this means no greenhouse gases are emitted
3.petrol vechiles emit greenhouse gases into the atmosphere
4.hydrogen fuel cells produce more energy per gram of hydrogen relative to petrol
what are the disadvantages of using hydrogen instead of petrol
- hydrogen has to be stored at high pressure and hydrogen gas is explosive
2.there are not many places to refuel either
when was earth formed
4.6 billion years ago q
what happened in the first billion years of earth existence
active volcaneos were littered across the earth surface and the frequent eruption of these volcanes resulted in the release
what effect did the frequenct eruptions in the first billions years of earths existence have
it resulted in the release of lots of carbon dioxide as well as smaller amount of gases like water vapour, ammonia, methane and nitrogen . scientists think that co2 dominated the early atmosphere in the same way modern mars does
what were oceans formed as a result of
water vapour condensing
what happen during the formation of the oceans
the formation of oceans caused a significant reduction in carbon dioxide levels in the atmosphere . carbonate precipates were formed by reactions between the dissolved carbon dioxide and seawater. these precipatates were deposited as sediment
what two things played importnat roles in the evolution of the earth atmosphere
volcanes and oceans
what increased the atmopsheric concentration of oxygen
photosynthesis
what is photosynthesis
photosynthesis is the process in whihc light energy is used to convert carbon dioxide and water into glucose and oxygen
what were the first photosynthetic organism s to evlole 2.7 billion years ago approx
algae
over the next billion years, more photosynthetic plants began to involve, what did this cause
increasing rate of oxygen accumulating in the atmosphere
a threshold concentration of oxygen was reached, what did this allow
more complex life forms to evolve such as animals
what is the chemical formula for oxygen
O2
what is the chemical formula for carbon dioxide
CO2
what is the chemical formmula for water
H2O
what is the chemical formula for glucose
C6H12O6
how did marine animals caused atmoshpheric carbon dioxide to decrease
marine animals evolved, this removed carbonates from the oceans as animals used these to build their shells and skeletons
how did oceans cause the atomospheric carbon dioxide to decrease
the formation of oceans caused a significant reduction in carbon dioxide levels in the atmosphere . carbonate precipates were formed by reactions between the dissolved carbon dioxide and seawater.
how did photpsynthesis cause the atomospheric carbon dioxide to decrease
carbon dixoide is one of the reactnarts in the equation for photosynthesis. therefore, the photosynthetic action of algae and plants removed carbon dioxide from the atmosphere
what three factors caused the atomsopheric carbon dioxide to dectrase
photosynthesis, oceans and marine animals
how do you test for oxygen
- insert a glowing splint into a test tube containing gas
2.if the gas is oxygen the splint will relight
what do greenhouse gases cause
the green house effect
what does the green house effect do
keeps the earth warm enough for life
what is the problem with the green house effect
can cause global warming if too intense
what is the process of the green house effect
1.The Sun emits short wavelength infrared radiation that enters the atmosphere and travels towards the Earth.
2.The Earth absorbs a portion of this radiation, but longer wavelength radiation is reflected back into the atmosphere.
3.Greenhouse gases can’t absorb the short wavelength radiation emitted by the Sun, but they can absorb the reflected radiation.
4.The gases re-radiate this as heat energy, some of which heads back to Earth.This increases the temperature at the Earth’s surface.
what can’t greenhouse gases absorb
the frequencies of radiation that arrive from the sun
what can greenhouse gases absorb
reflected radiation before reradiating it in all directions, including back towards earth
name three greenhouse gases
carbon dioxide, water vapour and methane
how does agriculture causethe atomospheric rates of greenhouse gases to increase
farm animals release methane during digestion
how does deforestation cause the atmopsheric rates if greenhouse gases to increase
as we cut donw more trees, the global rate of deforestation will decrease and because carbon dioxide is a reactnat in photosynthesis , this means less carbon dioxide will be removed from the atmosphere by this process
how does buring fossil fuels cause the atmospheric rates of greenhouse gases to increase
burning fossil fuels release carbon dioxide. this carbon dixodide has been stored away for millions of years previously
how does landfill sites cause the atmospheric rates of greenhouse gases to increase
the number and size of landfill sites increases
earth temperature naturally fluxates, what does the recent increase in temp correlate with
the increasing atmopsheric greenhouse concentrations
what is the current scientific consensus on what the increase greenhouse gas emissions caused by
it was caused by the changes to human activity which will lead to global climate change,this was done based on peer reviewed assessment
the global climate sustem is complicated, why is this bad
makes it difficult to create accirate models
what motives might people have to plaay down the contribution of greenhouse gas emissions to climate change
1.A common bias is that an individual is involved in an industry which relies on, for example, burning fossil fuels.
- Burning fossil fuels is central to this individual’s profession but it is also known to release lots of carbon dioxide, which is a greenhouse gas.
3.Therefore, it is in the individual’s interest to play down the negative effects of greenhouse gases in order to avoid more regulation of the relevant industry
why do peopel speculate about climate change based on simple models and inadequate information
because the global climate system is complicated, which makes it difficult to make accurate models
what is a significant cause of global clinate change q
increasing the avergae global temperaturr
what does the melting of polar ice caps cause
- sea levels to rise - this would cause flooding and erosion of costal regions
- some specices to be less successful hunters. for example the polar bear
what are 5 potinetial consequecnes to increasing the global avergae temp
- melting of polar ice caps
- meterlogical events - could increase in frequency and intensity
- changes in water avalibity - could affect how species are distributed
- changes in precipitation - cause some regions reciveing much less or much more rainfall than they previously did
- food shortage - could lead to famines
