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108 Cards in this Set

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What type of rock is limestone?
What is it made of?
What is the symbol equation?
Sedimentary
Calcium carbonate
CaCO3
What can limestone be used for?
Building materials
Making cement mortar and concrete
What is the problem with using limestone as a building material?
Limestone can be eroded by acid rain but this is a slow process
What happens when limestone is heated?
What scientific process is this?
It decomposes
Thermal decomposition
What is made when calcium oxide reacts with water?
Calcium hydroxide
What is calcium hydroxide used for?
Neutralises soils and lakes, preventing crop failure
What is the symbol equation for calcium oxide?
CaO
What products does calcium carbonate break down into when heated?
Calcium oxide and carbon dioxide
What is the symbol equation for calcium hydroxide?
Ca(OH)2
What is made when calcium hydroxide reacts with carbon dioxide?
Calcium carbonate
How is cement made?
When limestone and clay is roasted in a rotary kiln
How is mortar made?
When cement, sand and water are mixed
How is concrete made?
When mortar, aggregate, sand and water are mixed
What is a metal ore?
A mineral that contains enough metal to make it economically viable to extract
What does the method of metal extraction depend on?
How reactive the metal is
How can unreactive metals be obtained?
Through panning
How can metals that are less reactive than carbon be obtained?
Can be heated with carbon
What form are most metals found?
As metal oxides
How can metals that are more reactive than carbon be obtained?
Electrolysis
How is copper extracted?
Heating ores in a furnace, known as smelting
Copper is then purified by electrolysis
Which electrode do the copper ions go to?
The cathode because they are positively charged
What new methods are being used to extract copper due to a shortage of copper-rich ores?
Phytomining
Bioleaching of low grade copper ores
What is phytomining?
Uses plants to absorb copper
As the plant grows they absorb and store copper by removing it from the soil
Plants are then burned and the ash contains copper in relatively high quantities
What is bioleaching?
Uses bacteria to extract metals from low-grade ores
A solution containing bacteria is mixed with low-grade ore
Bacteria converts the copper into a solution where it can be easily extracted
What is the name of the copper solution that is created during bioleaching?
Leachate
How can iron be produced?
By reducing iron oxide in a blast furnace
How is steel made?
When carbon is added to irion
What is wrong with the iron obtained from a blast furnace?
It contains impurities which makes it very brittle so it has limited uses at this stage
The impurities must be removed to produce the useful pure iron for steel
What are the properties of steel with a high carbon content?
What are the properties of steel with a low carbon content?
Hard and strong
Soft and malleable
What are the advantages of stainless steel?
Hard
Resistant to corrosion
What are the properties of the transition metals?
Good conductors of heat and electricity
Hard and mechanically strong
High melting point (except mercury)
Malleable

Therefore very useful
How are aluminium and titanium extracted?
Electrolysis
What is copper useful for?
Wires (good conductor of electricity and ductile)
Pipes (unreactive and malleable)
What is aluminium used for?
Drinks cans - Light weight
Lightweight vehicles - Resistant to corrosion
Window frames - Low density
Aeroplanes
What is titanium used for?
Jet engines -Low density
Nuclear reactors - Resist corrosion
Replacement hip joints
Why is it important to recycle metals?
Save money and energy
Conserve natural resources
Reduce global warming
What is crude oil made of?
Mixture of hydrocarbons
Why can crude oil be distilled?
Because the hydrocarbons are not chemically combined together as it is a mixture so the properties of the substance remain unchanged such as boiling points
What type of hydrocarbons are present in crude oil?
Alkanes
What is the general formula for an alkane?
CnH2n+2
The number of hydrogen atoms is double the amount of carbon atoms and 2 extra
What is the formula for methane?
CH4
What is the formula for ethane?
C2H6
What is the formula for propane?
C3H8
What is the formula for butane?
C4H10
Why are alkanes saturated?
What property does this result in?
Because each atom is joined together to other atoms by a single bond

Relatively unreactive apart from combustion
What happens during fractional distillation?
Crude oil is evaporated and its vapours condense at different temperatures, separating them off through the fractions
What will each fraction contain?
Hydrocarbons with a similar number of carbon atoms so crude oil is not completely separated
What are the properties of the small hydrocarbons?
Low boiling points
Very volatile (how easy it turns into a gas)
Flows easily
Ignites easily
What are the properties of the large hydrocarbons?
High boiling points
Not very volatile (how easy it turns into a gas)
Does not flow easily
Does not ignite easily
What temperature is the bottom of the column?
350 degrees
What temperature is the top of the column?
25 degrees
From the top of the tower to the bottom, what is the order of the fractions and what are the products uses?
Refinery gases-Bottled gas
Gasoline/Petrol-Fuel for cars
Naphtha-Making chemicals
Kerosene-Aircraft fuel
Diesel oil-Fuel for cars, lorries,buses
Lubricating oil
Fuel oil-Fuel for ships, power stations
Bitumen-Road surfaces
What are the advantages of using hydrogen as a biofuel?
Water is the only product of combustion-Clean fuel
Water can be used to make hydrogen
What are the disadvantages of using hydrogen as a biofuel?
Currently no low energy ways to extract hydrogen from water
Hydrogen is a gas therefore it's difficult to store in large quantities
Hydrogen is flammable so there are considerable safety issues
What are the advantages of using ethanol as a biofuel?
Renewable source of energy so therefore preserves fossil fuels
Sugar beet is what is used to produce ethanol, a plant that grows rapidly in hot climates
Sugar beet aborts carbon dioxide from the atmosphere and therefore decreases the rate of global warming
What are the disadvantages of using ethanol as a biofuel?
Sugar beet can only be grown in a hot country
Carbon dioxide is a produce of combustion
What are biofuels?
Fuels that are produced from plant matter such as sugar
Why are alkanes saturated?
Because each carbon atom has as many bonds formed with hydrogen atoms as possible due to the single bond
What process occurs when you break down long hydrocarbon chains into smaller ones?
Cracking
Why do we break down long hydrocarbon chains?
Because they are more useful for things such as fuel
What does cracking involve?
Heating the hydrocarbon until it vaporises
Passing vapour over a hot catalyst
What sort of reaction is cracking?
Thermal decomposition
What test is used to discover an alkene?
Bromine water that turns from orange to colourless
What sort of bond does an alkane have?
Single bond
What sort of bond does an alkene have?
Double bond
What is the general formula for an alkene?
CnH2n
What 2 ways is ethanol produced?
Reacting ethene and steam in the presence of a phosphoric acid catalyst >>> Ethanol
Fermentation of sugar >>> Ethanol and carbon dioxide
What are alkenes used for?
Why?
Making polymers
Because of the double bond
What is the process of converting alkenes into polymers?
Polymerisation
What are plastics?
Synthetic polymers
What is slime made from?
Poly(ethenol)
Why does the viscosity of slime vary?
Temperature
Concentration of poly(ethanol)
Concentration of borax
What is used in biodegradable plastics?
Polymers
Cornstarch
What medical uses are there of polymers?
Implantable materials used for tissue surgery
Hard-wearing anti-bacterial dental cements, coatings and fillers
Hydrogels used as wound dressings

Also used to coat fabrics with a waterproof layer
What does PVC stand for?
Polyvinyl chloride
What is PVC used for?
Waterproof items
Drainpipes
Electrical insulators
What is polystyrene used for?
Casings of electrical appliance's
Protective packaging
Disposable cups
What is poly(ethene) used for?
Plastic bags
Bottles
What is poly(propene) used for?
Crates
Ropes
How an oils be removed from plants?
Pressing/Crushing
Distillation
What are the characteristics of vegetable oil?
Unsaturated
Double carbon-carbon bond
Alkene
Why are vegetable oils used in cooking?
Higher boiling points than water so they can cook food at higher temperature resulting in the food being cooked quicker
Different flavour added
Using vegetable oil increases the energy released by food when consumed
What is generally the problem with the amount of double bonds in a substance?
They can lower the melting point
What do unsaturated oils tend to have?
Melting points below room temperature
How can the melting point of an oil be raised?
What does this result in?
What is this process called?
Removing some of its double bonds
It hardens the oil into a solid fat (margarine)
Hydrogenation
What is the process of hydrogenation?
Unsaturated fat is heated with hydrogen at 60 degrees in the presence of a nickel catalyst
This removes the double carbon-carbon bonds to form a saturated fat (hydrogenated oil)
What are the characteristics of an emulsion?
Thicker than oil or water
Better texture
Better appearance
Better coating ability
What are some examples of emulsions?
Salad dressings
Ice cream
Cosmetics
Paints
What is an emulsifier?
A substance that helps to stabilise an emulsion
What do emulsifier molecules contain?
Hydrophilic head that mixes with water molecules
Hydrophobic tail that mixes with oil molecules
What is the core made of?
Nickel and iron
What was the early theory for the creation of mountain ranges?
Caused by the shrinkage of the crust when the Earth cooled down after its formation
But this theory has been rejected due to scientists finding more about the Earth
What do the coasts of west Africa and east South America have in common?
Closely matched coastlines in shape
Similar rock patterns which contain fossils of the same plants and animals such as the Mesosaurus
What did Alfred Wegener propose?
South America and Africa were once a single land mass
Proposed the movement of the crust was responsible for the separation of the land- Continental drift which is the tectonic theory
Why wasn't Wegener's theory supported until 50 years later?
Because there was no evidence as to how the crust moved
What causes convection currents?
Intense heat released due to radioactive decay deep in the Earth
What is the Earth's lithosphere?
Crust and upper part of the mantle
What was the Miller Urey experiment?
Attempt to test one possible theory for how life on Earth began

Mixed together chemicals that were thought to be present in the Earth's early atmosphere (water, ammonia and methane)

Mixture was heated and sparks to represent ultraviolet radiation from the Sun

Mixture cooled and cycle was repeated

After many cycles the mixture contained simple organic molecules (amino acids) that are the building blocks of living organisms
What is the Miller Urey experiment known as?
Primordial soup theory
What was the Earth's atmosphere like 4 billion years ago?
Why is this?
Majority of it was carbon dioxide
Small proportions of methane and ammonia
Water vapour which condenses to form oceans

Intense volcanic activity
What was the Earth's atmosphere like 2 billion years ago?
Why is this?
Carbon dioxide is reduced but is still a large percentage
Nitrogen and oxygen are now present
Small proportions of methane and ammonia are still present

-Green plants and algae have evolved which reduced carbon dioxide levels and creates oxygen
-Microorganisms that cannot tolerate oxygen die out
-Carbon from carbon dioxide becomes locked up in sedimentary rocks formed from skeletons of marine animals
-Gases react with oxygen to release nitrogen
-Nitrogen is also produced by bacteria removing nitrates from decaying plants
What is the Earth's atmosphere like today?
Nitrogen 78%
Oxygen 21%
Carbon dioxide 0.03%
Argon and other noble gases 1%
Water vapour varies between 0-3%
Why are levels of carbon dioxide in todays atmosphere increasing?
Volcanic activity
Burning of fossil fuels
Why does volcanic activity increase carbon dioxide?
Geological activity moves carbonate rocks deep into the Earth
During volcanic activity they may release carbon dioxide back into the atmosphere
Why does burning fossil fuels increase carbon dioxide?
Burning carbon that has been locked up in fossil fuels released carbon dioxide into the atmosphere
What reaction is reducing carbon dioxide in the atmosphere?

What does this reaction produce?

What are the negative impacts of this process?
Reaction between carbon dioxide and sea water

Insoluble carbonates that are deposited as sediment
Soluble hydrogencarbonates
The carbonates form some of the sedimentary rock in the Earth's crust

Too much carbon dioxide dissolved in the oceans will harm marine life
How can the different gases in air be collected?
Through fractional distillation
Cool the air to a liquid and then heat it
What does calcium carbonate break down into when heated?
Calcium oxide and carbon dioxide