Topic 8 - Fuels and Health Science Flashcards
Functional group
The part of a molecule that provides characteristic chemical reactivity
Organic chemistry
The chemistry of the element carbon and compounds that contain it
Carbon is in this group of the periodic table
4
Carbon is in this period of the periodic table
2
Allotrope
Different forms of the same element
Volatility
How easily a liquid vaporises to become a gas
Viscosity
A liquid’s resistance to flow
Does not flow easily
If a substance has a high viscosity it…
Does flow easily
If a substance has a low viscosity it…
If a substance has a high volatility it…
Easily goes from a liquid to a gas
If a substance has a low volatility it…
Does NOT easily go from a liquid to a gas
Evaporation
The change of state from a liquid to a gas
Condensation
The change of state from a gas to a liquid
Hydrocarbon
A compound that only contains the elements hydrogen and carbon
Homologous series
A group of molecules that have similar chemical properties
Fractional distillation
The method used to separate the components of crude oil
Fractionating column
The apparatus in which the crude oil is separated
At the top of the fractionating column, the crude oil fractions have these physical properties
- low boiling points, low viscosity, high volatility
At the top of the fractionating column, the crude oil fractions have these chemical properties
- Easy to ignite / high flammability
At the top of the fractionating column, the molecules in the crude oil fractions are
small with few carbon atoms
Alkene general formula
CnH2n
Alkane general formula
CnH2n+2
Monkeys Eat Peanut Butter
Mnemonic for remembering the first 4 molecules in a homologous series
The attraction between molecules
Intermolecular forces
Larger alkane molecules with higher boiling points have ______ intermolecular forces because ______
Larger, they have more bonds to hold
oil fractions mostly contain …
alkanes
the main features of a homologous series
similar chemical properties and with a gradation in physical properties
why alkanes form a homologous series
they have similar chemical properties to each other and they have trends in physical properties
Why is Crude oil important in the petrochemical industry?
It is refined into petroleum products that people use for many different purposes including propelling vehicles, heating buildings, and producing electricity.
complete combustion of hydrocarbons
complete combustion happens when there is a good supply of air, carbon dioxide and water are produced.
why carbon monoxide is toxic
it displaces oxygen in the blood and deprives the heart, brain and other vital organs of oxygen
harmful products made in incomplete combustion of hydrocarbons
water carbon monoxide and carbon (soot).
problems with incomplete combustion
carbon monoxide is a poisonous gas
how some hydrocarbon fuels release sulfur dioxide in use
hydrocarbon comes from living matter which contains amino acids including sulfur
pollutants in acid rain
sulfur dioxide and nitrogen oxides
Effects of acid rain
Erode buildings and other infrastructures, contaminate: Soil, Plants, and Water sources
why oxides of nitrogen are released when burning fuels
high temperatures are reached. at these high temperatures, nitrogen and oxygen from the air combine to produce nitrogen monoxide
what happens during cracking
when complex molecules such as kerogens or long-chain hydrocarbons are broken down into simpler molecules
why alkanes are saturated
all the carbon molecules are bonded together by single bond
why alkenes are unsaturated
they have double bonds between the carbons
why cracking is necessary
it helps to match the supply of fractions with the demand for them and it produces alkenes, which are useful for the petrochemical industry.
Fractions of crude oil (RPNKDLFB)
Refinery gas (bottled gas). Petrol (fuels cars). Naphtha (chemicals). Kerosene (jet fuel). Diesel (fuels vehicles). Lubrication oil (waxes and polishes). Fuel oil (for ships, factories and central heating). Bitumen (roads and roofing)
Test for water
Add anhydrous copper sulphate which is white. Turns blue when it becomes hydrated.
Test for carbon dioxide
Turns limewater cloudy
Normal alkene formed during cracking
Ethene (C2H4)
Why do you have to replace the cap to put out an alcohol burner?
Blowing it out would blow fuel off the wick, changing the final mass recorded
How and when did Earth’s atmosphere form?
4.4-4 billion years ago. As Earth cooled, volcanism started to occur and volcanic gasses created Earth’s atmosphere, such as nitrogen, oxygen, carbon dioxide, hydrogen and water vapour
What is the atmosphere?
the layer of gases that surrounds Earth
How and when did the oceans form?
3.2 billion years ago, The water vapour from the volcanic activity condensed and formed the oceans
Why did the amount of carbon dioxide in the atmosphere decrease?
carbon dioxide reacted with water in the ocean to form carbonic acid, which dissolves in water to form carbonate (which forms rocks)
How much carbon dioxide is in the atmosphere?
0.04%
How much carbon dioxide used to be in the atmosphere?
70%
How did photosynthesizing prokaryotes, such as cyanobacteria, change the Earth’s atmosphere?
They underwent respiration, using up carbon dioxide and producing oxygen
What is the composition of the atmosphere?
78% nitrogen, 21% oxygen, 1% other (water, carbon dioxide, methane, argon)
Test for oxygen
Relights a glowing splint
What is the greenhouse effect?
the trapping of the sun’s warmth in a planet’s lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet’s surface.
Give three greenhouse gases
Carbon dioxide, methane, water vapour
Evidence for human induced climate change
The graphs showing carbon dioxide levels and global average temperature over the last 200 years correlate. However, one must consider historical accuracy of measurements.
How are greenhouse gases produced?
Methane - animals bowels, rice, from landfill sites. CO2 - burning fossil fuels
Evidence for oxygen forming
Iron pyrite becoming iron oxide in presence of oxygen (seen in rock layers) - happened same time as stromatolites formed
How do we estimate our early atmosphere?
Compare to other rocky planets with similar circumstances (Venus, mars)
