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108 Cards in this Set
- Front
- Back
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What type of rock is limestone?What is it made of?What is the symbol equation?
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Sedimentary Calcium carbonate CaCO3
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What can limestone be used for?
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Building materialsMaking cement mortar and concrete
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What is the problem with using limestone as a building material?
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Limestone can be eroded by acid rain but this is a slow process
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What happens when limestone is heated?What scientific process is this?
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It decomposes Thermal decomposition
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What is made when calcium oxide reacts with water?
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Calcium hydroxide
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What is calcium hydroxide used for?
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Neutralises soils and lakes, preventing crop failure
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What is the symbol equation for calcium oxide?
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CaO
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What products does calcium carbonate break down into when heated?
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Calcium oxide and carbon dioxide
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What is the symbol equation for calcium hydroxide?
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Ca(OH)2
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What is made when calcium hydroxide reacts with carbon dioxide?
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Calcium carbonate
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How is cement made?
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When limestone and clay is roasted in a rotary kiln
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How is mortar made?
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When cement, sand and water are mixed
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How is concrete made?
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When mortar, aggregate, sand and water are mixed
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What is a metal ore?
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A mineral that contains enough metal to make it economically viable to extract
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What does the method of metal extraction depend on?
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How reactive the metal is
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How can unreactive metals be obtained?
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Through panning
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How can metals that are less reactive than carbon be obtained?
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Can be heated with carbon
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What form are most metals found?
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As metal oxides
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How can metals that are more reactive than carbon be obtained?
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Electrolysis
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How is copper extracted?
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Heating ores in a furnace, known as smelting Copper is then purified by electrolysis
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Which electrode do the copper ions go to?
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The cathode because they are positively charged
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What new methods are being used to extract copper due to a shortage of copper-rich ores?
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Phytomining Bioleaching of low grade copper ores
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What is phytomining?
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Uses plants to absorb copperAs 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
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What is bioleaching?
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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
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What is the name of the copper solution that is created during bioleaching?
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Leachate
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How can iron be produced?
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By reducing iron oxide in a blast furnace
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How is steel made?
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When carbon is added to irion
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What is wrong with the iron obtained from a blast furnace?
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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
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What are the properties of steel with a high carbon content?What are the properties of steel with a low carbon content?
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Hard and strongSoft and malleable
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What are the advantages of stainless steel?
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Hard Resistant to corrosion
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What are the properties of the transition metals?
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Good conductors of heat and electricity Hard and mechanically strong High melting point (except mercury)Malleable Therefore very useful
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How are aluminium and titanium extracted?
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Electrolysis
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What is copper useful for?
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Wires (good conductor of electricity and ductile)Pipes (unreactive and malleable)
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What is aluminium used for?
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Drinks cans - Light weightLightweight vehicles - Resistant to corrosion Window frames - Low density Aeroplanes
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What is titanium used for?
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Jet engines -Low densityNuclear reactors - Resist corrosion Replacement hip joints
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Why is it important to recycle metals?
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Save money and energy Conserve natural resources Reduce global warming
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What is crude oil made of?
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Mixture of hydrocarbons
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Why can crude oil be distilled?
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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
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What type of hydrocarbons are present in crude oil?
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Alkanes
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What is the general formula for an alkane?
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CnH2n+2The number of hydrogen atoms is double the amount of carbon atoms and 2 extra
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What is the formula for methane?
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CH4
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What is the formula for ethane?
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C2H6
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What is the formula for propane?
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C3H8
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What is the formula for butane?
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C4H10
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Why are alkanes saturated?What property does this result in?
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Because each atom is joined together to other atoms by a single bond Relatively unreactive apart from combustion
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What happens during fractional distillation?
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Crude oil is evaporated and its vapours condense at different temperatures, separating them off through the fractions
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What will each fraction contain?
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Hydrocarbons with a similar number of carbon atoms so crude oil is not completely separated
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What are the properties of the small hydrocarbons?
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Low boiling points Very volatile (how easy it turns into a gas)Flows easily Ignites easily
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What are the properties of the large hydrocarbons?
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High boiling points Not very volatile (how easy it turns into a gas)Does not flow easily Does not ignite easily
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What temperature is the bottom of the column?
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350 degrees
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What temperature is the top of the column?
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25 degrees
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From the top of the tower to the bottom, what is the order of the fractions and what are the products uses?
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Refinery gases-Bottled gasGasoline/Petrol-Fuel for carsNaphtha-Making chemicals Kerosene-Aircraft fuel Diesel oil-Fuel for cars, lorries,busesLubricating oilFuel oil-Fuel for ships, power stations Bitumen-Road surfaces
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What are the advantages of using hydrogen as a biofuel?
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Water is the only product of combustion-Clean fuel Water can be used to make hydrogen
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What are the disadvantages of using hydrogen as a biofuel?
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Currently no low energy ways to extract hydrogen from waterHydrogen is a gas therefore it's difficult to store in large quantities Hydrogen is flammable so there are considerable safety issues
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What are the advantages of using ethanol as a biofuel?
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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
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What are the disadvantages of using ethanol as a biofuel?
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Sugar beet can only be grown in a hot country Carbon dioxide is a produce of combustion
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What are biofuels?
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Fuels that are produced from plant matter such as sugar
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Why are alkanes saturated?
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Because each carbon atom has as many bonds formed with hydrogen atoms as possible due to the single bond
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What process occurs when you break down long hydrocarbon chains into smaller ones?
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Cracking
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Why do we break down long hydrocarbon chains?
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Because they are more useful for things such as fuel
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What does cracking involve?
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Heating the hydrocarbon until it vaporisesPassing vapour over a hot catalyst
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What sort of reaction is cracking?
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Thermal decomposition
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What test is used to discover an alkene?
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Bromine water that turns from orange to colourless
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What sort of bond does an alkane have?
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Single bond
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What sort of bond does an alkene have?
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Double bond
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What is the general formula for an alkene?
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CnH2n
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What 2 ways is ethanol produced?
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Reacting ethene and steam in the presence of a phosphoric acid catalyst >>> EthanolFermentation of sugar >>> Ethanol and carbon dioxide
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What are alkenes used for?Why?
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Making polymers Because of the double bond
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What is the process of converting alkenes into polymers?
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Polymerisation
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What are plastics?
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Synthetic polymers
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What is slime made from?
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Poly(ethenol)
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Why does the viscosity of slime vary?
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Temperature Concentration of poly(ethanol)Concentration of borax
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What is used in biodegradable plastics?
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Polymers Cornstarch
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What medical uses are there of polymers?
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Implantable materials used for tissue surgery Hard-wearing anti-bacterial dental cements, coatings and fillers Hydrogels used as wound dressingsAlso used to coat fabrics with a waterproof layer
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What does PVC stand for?
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Polyvinyl chloride
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What is PVC used for?
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Waterproof items Drainpipes Electrical insulators
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What is polystyrene used for?
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Casings of electrical appliance'sProtective packaging Disposable cups
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What is poly(ethene) used for?
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Plastic bags Bottles
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What is poly(propene) used for?
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Crates Ropes
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How an oils be removed from plants?
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Pressing/CrushingDistillation
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What are the characteristics of vegetable oil?
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Unsaturated Double carbon-carbon bondAlkene
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Why are vegetable oils used in cooking?
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Higher boiling points than water so they can cook food at higher temperature resulting in the food being cooked quicker Different flavour addedUsing vegetable oil increases the energy released by food when consumed
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What is generally the problem with the amount of double bonds in a substance?
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They can lower the melting point
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What do unsaturated oils tend to have?
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Melting points below room temperature
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How can the melting point of an oil be raised?What does this result in?What is this process called?
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Removing some of its double bonds It hardens the oil into a solid fat (margarine)Hydrogenation
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What is the process of hydrogenation?
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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)
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What are the characteristics of an emulsion?
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Thicker than oil or waterBetter texture Better appearance Better coating ability
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What are some examples of emulsions?
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Salad dressings Ice cream Cosmetics Paints
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What is an emulsifier?
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A substance that helps to stabilise an emulsion
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What do emulsifier molecules contain?
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Hydrophilic head that mixes with water molecules Hydrophobic tail that mixes with oil molecules
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What is the core made of?
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Nickel and iron
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What was the early theory for the creation of mountain ranges?
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Caused by the shrinkage of the crust when the Earth cooled down after its formationBut this theory has been rejected due to scientists finding more about the Earth
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What do the coasts of west Africa and east South America have in common?
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Closely matched coastlines in shape Similar rock patterns which contain fossils of the same plants and animals such as the Mesosaurus
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What did Alfred Wegener propose?
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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
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Why wasn't Wegener's theory supported until 50 years later?
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Because there was no evidence as to how the crust moved
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What causes convection currents?
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Intense heat released due to radioactive decay deep in the Earth
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What is the Earth's lithosphere?
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Crust and upper part of the mantle
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What was the Miller Urey experiment?
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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
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What is the Miller Urey experiment known as?
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Primordial soup theory
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What was the Earth's atmosphere like 4 billion years ago?Why is this?
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Majority of it was carbon dioxide Small proportions of methane and ammonia Water vapour which condenses to form oceans Intense volcanic activity
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What was the Earth's atmosphere like 2 billion years ago?Why is this?
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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
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What is the Earth's atmosphere like today?
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Nitrogen 78%Oxygen 21%Carbon dioxide 0.03%Argon and other noble gases 1%Water vapour varies between 0-3%
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Why are levels of carbon dioxide in todays atmosphere increasing?
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Volcanic activity Burning of fossil fuels
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Why does volcanic activity increase carbon dioxide?
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Geological activity moves carbonate rocks deep into the Earth During volcanic activity they may release carbon dioxide back into the atmosphere
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Why does burning fossil fuels increase carbon dioxide?
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Burning carbon that has been locked up in fossil fuels released carbon dioxide into the atmosphere
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What reaction is reducing carbon dioxide in the atmosphere?What does this reaction produce?What are the negative impacts of this process?
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Reaction between carbon dioxide and sea waterInsoluble carbonates that are deposited as sediment Soluble hydrogencarbonatesThe carbonates form some of the sedimentary rock in the Earth's crust Too much carbon dioxide dissolved in the oceans will harm marine life
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How can the different gases in air be collected?
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Through fractional distillation Cool the air to a liquid and then heat it
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What does calcium carbonate break down into when heated?
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Calcium oxide and carbon dioxide
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