fuels and earth science Flashcards
what hydrocarbon
compound made from ONLY carbon and hydrogen
what crude oil
- complex mixture of many different hydrocarbon
- formed at high pressure and temps
- finite
- alkane
- chains or rings
what to use to separate crude oil
- fractional distillation
* splits into fractions
how to separate crude oil
- pumped into column
- hydrocarbons with low bp evaporate and condense
- all have different bp, different times and fractions
similar fractions
- similar hydrocarbons have same carbon atoms
- lots of carbon atoms have high bp, condense bottom
- less carbon atoms low bp, condense top
why crude oil fractions
all have different uses
what bitumen for
surface roads and roof building
what fuel oil for
fuel large ships or power stations
what diesel for
fuel big cars and lorries
what kerosene for
fuel aircrafts
what petroleum for
fuel in cars
what gases for
domestic heating appliances
what homologous series
groups of hydrocarbons with similar properties
what homologous similar unit
CH2
types of properties of hydrocarbons that can be distinguished by
- boiling points
- ease of ignition
- viscosity
boiling point
- intermolecular forces of attraction stronger in bigger molecule
- longer length more molecules
- need more energy to break forces
ease of ignition
- shorter, more easier to ignite
- lower boiling point, gases
- gas molecules mix with air, contact with spark flames
viscosity
- stronger forces of attraction, harder to flow
* longer (stronger) very viscous
complete combustion
- burning hydrocarbons
- carbon and hydrogen react with oxygen from air
- forms CO2 and water
- plenty of oxygen
equation of complete combustion
hydrocarbon + oxygen > CO2 + water
incomplete combustion
*burning hydrocarbon with insufficient amount of oxygen in air
equation of incomplete
hydrocarbon + oxygen > carbon + carbon monoxide + water
what soot
- carbon in solid form
- in atmosphere
- reduce air quality, building dirty
what carbon monoxide
- toxic gas
* can combine with haemoglobin in bool cells, less oxygen transported
how sulfur dioxide produced
when burning hydrocarbon fuels which have sulphur impurities
reacts with air forming sulphur dioxide
how acid rain produced
sulphur dioxide evaporates into the air and reacts with water in the clouds to form sulphuric acid
problems of acid rain
corrodes buildings/statues made from limestone
damages crops
lowers ph of large bodies water
how oxides of nitrogen produced
in engines of cars the high temperatures and pressures causes nitrogen and oxygen to react with the air
problems with oxides of nitrogen
it is a pollutant
produces acid rain with similar effects of sulphur oxide
causes respiratory problems
advantage of using hydrogen as fuel in cars
releases more energy per kilo compare to other fuels
water is only the only pollutant
renewable
disadvantage of hydrogen as fuel in cars
expensive to produce and lots of energy required for electrolysis
difficult to store as hydrogen is easily ignited
non renewable fossils fuel in natural gas
methane
what is cracking
process of breaking down large hydrocarbon molecules into smaller more useful ones
saturated alkanes cracked into shorter chain alkanes and unsaturated alkenes
what is saturates
only single bonds
what is unsaturated
contain some C=C double bonds
what type of reaction is cracking
thermal decomposition
why cracking needed
high demand for shorter chain alkenes and alkanes
how formation of early atmosphere
volcanic activity
earths surface was molten with no atmosphere
cooling caused landmasses to solidify
volcanoes are formed on and land and released gases which forms atmosphere
what was thought the earths atmosphere contained
lots of CO2
little to none O and water vapour
small amounts of other gases
how oceans formed
when I called water vapour in atmosphere condense
ways carbon dioxide in the atmosphere decrease after oceans formed
absorption by the oceans
absorption by plants and algae
how carbon dioxide decreased from absorption by oceans
CO2 can be dissolved into then
goes through reactions
stored in sediments
how CO2 decreased by absorption by plants and algae
primitive green plants and algae absorb some carbon dioxide from atmosphere when used in photosynthesis
how amount of oxygen increased in atmosphere
growth of any plants use carbon dioxide for photosynthesis and released oxygen
increase the amount of oxygen and increased carbon dioxide
photosynthesis equation
6CO2 + 6H2O -> C6H12O6 + 6O2
how to test for oxygen
place glowing splint inside test tube containing gas
Glowing split will really like if oxygen is present
what is a greenhouse gas
a gas that can absorb and re-radiate long wavelength of radiation
example of greenhouse gas
methane, carbon dioxide, water vapour
what is the greenhouse effect
sun emits short wavelength of electromagnetic radiation
passes through atmosphere
the earth absorbs some radiation and warms up
and then re-emitted as long wavelength of infrared radiation
IR is absorbed by greenhouse gases then reradiated in all directions including the Earth
has human activities caused a rise in greenhouse gases
greenhouse gas concentration has increased in the atmosphere, enhances greenhouse affect as more infrared radiation is absorbed and re-radiated back to earth so more warmer, global warming
types of human activities that causes more greenhouse gases
having an increased energy consumption
deforestation
methane and farming
how increased energy consumption created more greenhouse gases
human population increased and have become more industrialised
burning of fossil feels for energy releases carbon dioxide
released into the atmosphere as CO2
how deforestation has created more greenhouse gases
Increase tune population needs more land for houses and crops to grow
increase to in population needs more land for houses and crops to grow
removing forests creates extra space
reduces the amount of photosynthesis occurring so less carbon dioxide removed and oxygen produced
how methane and farming has increased greenhouse gases
larger population needs more farming using cowls and paddyfields which produce lots of methane
evaluate evidence that human activity causing climate change
correlation between carbon dioxide concentration and temperature change
challenges of obtaining climate change data
historical data is less accurate and location of the measurements are not precise
effects of global warming
melting of the polar ice caps frequency
severity of storms increase
rainfall patterns changes
current compositions of earths atmosphere
nitrogen 78%
oxygen 21%
argon 0.93%
carbon 0.04%
how effects of global warming be mitigated
constructing flood defences in low-lying areas
using irrigation systems to provide water in drought
produce alternative crops which are better adapted to new environment
