C1

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How would you work out the number of protons, neutrons & electrons in an atom?
No. of protons = atomic number = No. of electrons. No. of neutrons = mass no. – Atomic no.
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What can Limestone (CaCO₃) be used for?
To make calcium oxide & cement (by mixing CaCO₃ with clay & heating in a kiln). Make concrete by mixing cement with sand, aggregate & water. CaCO₃  CaO + CO₂ . Calcium Carbonate (thermal decomposition) Calcium Oxide + Carbon dioxide
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How do all metal carbonates react with acids when heated/reacted?
Metal carbonates decompose to the metal oxide & CO₂ when heated strongly enough.
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How do you test for Carbon dioxide?
Limewater – turns cloudy as it reacts with CO₂-->insoluble calcium carbonate (CaCO₃)
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What are the main stages involved in the ‘Limestone reaction cycle?”
CaCO₃ (thermal decomposition) CO₂ + Calcium Oxide(CaO). +H₂OCalcium hydroxide. +little H₂O and filterCalcium hydroxide solution. +CO₂--> Limestone (CaCO₃)
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What are the pros and cons of Limestone quarrying?
Pros – More employment opportunities for local people, more customers & trade for local businesses, improved roads. Cons – Dust & noise, more traffic, loss of habitats for wildlife.
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What is an ore?
A rock that contains enough metal to be worth extracting the metal.
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What kind of metal can be separated from rocks by physical methods?
Metals low in the reactivity series (unreactive).
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How can metals be separated from compounds?
Reduction – Carbon removes metals less reactive carbon from oxides
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Which metal ore is reduced in a blast surface using carbon (@high temp)?
Iron ores (produce 96%iron) Impurities make it brittle. Pure iron is too soft for many uses.
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What are steels?
Alloys of iron. Low carbon steels = easily shaped. High carbon steels = hard. Stainless steels resist corrosion.
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What kind of metal requires extraction by electrolysis?
Aluminium as it is more reactive than carbon & therefore can’t be reduced using carbon. Must be extracted by electrolysis of molten aluminium oxide. Requires a lot of electricity (high temp) = expensive.
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What are the similarities between titanium & aluminium?
Low density + resistant to corrosion.
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How can copper be extracted?
Smelting (heating in furnace) copper-rich ores = impure copper purified by electrolysis (lots of electricity + heat).
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Copper rich ores are a limited resource. What are the new ways scientists are inventing to extract copper from low grade ores (enviro-friendly)?
Phytomining – burning plants to produce ash from which copper can be extracted (from the ground) and Bioleaching uses bacteria to produce solutions containing copper compounds.
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How can copper be extracted from solutions of copper compounds?
Electrolysis or solutions can be reacted with a metal more reactive than copper to displace the copper.
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What properties are needed for electrical wiring?
Good conductors of electricity, malleable/ductile, resistant to corrosion.
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Why is Gold used in wedding rings mixed with other metals?
Make it stronger + Gold = expensive.
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Why should we recycle metals?
Saves energy (fossil fuels) needed to extract metal. Saves resources as less ore needs to be mined.
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What are the pros and cons of using metals in construction?
Pros = strong, malleable, ductile + good conductors. Cons = extracting metals from ores (pollution + using limited resources), more expensive than other materials (i.e. concrete), iron & steel can rust.
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How can you separate a mixture of liquids?
By distillation. Simple distillation of crude oils can produce fractions (liquids) that boil with different temp ranges.
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How is fractional distillation done?
Fractional distillation is done continuously by vaporising the mixture and condensing the fractions at different temperatures.
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What makes fractions with low boiling points useful as fuels?
Low viscosity (runny liquids), Flammable (ignite easily) & burn with clean flames (produce little smoke).
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What happens when hydrocarbons burn completely?
Oxidised to CO₂ & H₂O.
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What might incomplete combustion produce in a limited supply of air?
Carbon monoxide (poisonous), maybe Carbon (CO₂ = global warming) & particulates (unburnt hydrocarbons that reflect sunlight causing global dimming) & solid particles containing soot (carbon).
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What environmental problems are caused by fossil fuels?
Produces sulphur dioxide & nitrogen oxides which can cause acid rain.
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How can we remove harmful substances from waste gases before they are released into the atmosphere?
Sulfur dioxide removed from waste gases from power stations. Exhaust cars fitted with catalytic converters to remove carbon monoxide & nitrogen oxides. Filters remove particulates. Sulfur removed from fuels before supplied to users.
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What are Biofuels /Biodiesel? Give an example.
Biofuels made from plant/animal products. Biodiesel made from vegetable oils (extracted from plants) i.e. Ethanol made from sugar cane/beet.
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What are the pros & cons of using hydrogen as a fuel?
Pro=only produces water when burned. Con= Is a gas so needs a large volume (hard to store in cars). Produced from water by electrolysis (lots of energy).
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What is cracking and how can it be done?
Breaking down large hydrocarbon molecules into smaller molecules. Can be done by: passing hydrocarbon vapours over a hot catalyst or by heating a hydrocarbon + steam mixture.
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What are alkanes and Alkenes?
Alkanes= saturated hydrocarbons CnH2n+2. Alkenes = unsaturated hydrocarbons CnH2n. Alkenes have a double bond & react with bromine water turning it from orange to colourless
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How can different mixtures of alkanes and alkenes be produced by cracking?
By using different hydrocarbons and conditions
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What is polymerisation?
When monomers join to form polymers. i.e. ethenepoly(ethene). The double bond in each ethene molecule becomes a single bond and thousands of ethene molecules join to form long chains.
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What can polymers be used for?
Bags, bottles, filling pillows/duvets, stitches for wounds that change shape when body temp, wound dressing, dental fillings etc.
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What are the problems caused by polymers that aren't biodegradable (most of them)?
Unsightly rubbish, harm wildlife, take up valuable space in landfill sites difficult to sort from biodegradable plastics.
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How can you create biodegradable plastics?
By mixing cornstarch (plant material) into the plasticbroken down by micro-organismsmixed into soil/compost.
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What two methods are used to extract vegetable oils?
1. Crushing & pressing seeds, nuts and fruitsremoving water/impurities. 2. Distilling the plant material mixed with waterproduces oil + water mixtureremove oil.
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What can vegetable oils be used for?
Provides us lots of energy + nutrients when eaten. Good fuels, used to make biofuels (biodiesel). Boiling points higher than water so food cooked faster, changes flavour, texture, colour of food.
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Why are some vegetable oils described as unsaturated?
The Carbon double bonds (C=C) in the hydrocarbon chains are unsaturated. Several double bonds in each molecule = polyunsaturated. Unsaturated oils react with bromine water turning it orange or colourless.
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What is hydrogenation?
When unsaturated oils are reacted at 60°C using a nickel catalyst so that some/all of the carbon carbon double bonds become single bonds. Hydrogenated oils have higher melting points because they are more saturated (solid at room temp).
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What are emulsions?
Oil + water don’t mix forming 2 layers, when we shake/stir/beat the liquids together, tiny droplets form that are slow to separate = emulsion.
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How can you recognise an emulsion?
Opaque & thicker than the oil & water they are made from. Improves texture, appearance & ability to coat/stick to solids i.e. milk, cream, salad dressings, water based paints etc.
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Name the layers of the earth?
Inner core, Outer core, mantle, crust atmosphere
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How are earthquakes, mountains & volcanoes formed?
Radioactive decay heat up the mantle causing convection currents which cause tectonic plates to move, but when they meet, huge forces build up causing this.
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Why can’t scientists predict when and where earthquakes will occur?
As they don’t know enough about what is happening inside the earth.
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Why weren’t Wegner’s ideas of continental drift not accepted for many years?
As Wegner couldn’t explain why the continents moved. In 1915 scientists believed that the Earth was shrinking as it cooled.
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What, when and how was the early atmosphere formed?
About 4.5 billion years ago, volcanoes released CO₂, water vapour & nitrogen. Some scientists believe that there was also nitrogen, methane + ammonia.
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What produced oxygen in the atmosphere?
Algae + plants (probs evolved from plankton/algae) used CO₂ for photosynthesis & released oxygen. CO₂ decreased & O₂ increased.
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What was the Miller-Urey experiment?
Used mixture of H₂O, H, methane + ammonia & used high volt spark to simulate lightning-->produced amino acids (building blocks for proteins).
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What does one theory (other than the Miler-Urey experiment) suggest?
That organic materials formed a ‘primordial soup’ & that amino acids in this mixture combined to make proteins from which life began.
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In what ways did carbon from carbon dioxide become locked up?
In fossil fuels, in sedimentary rocks (limestone)
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What are the approximate percentages of gases in our atmosphere?
Nitrogen (78%), Oxygen (21%) + other gases (CO₂, water vapour + noble gases = 1%)
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How can gases be separated using fractional distillation?
Have different boiling points. The air is cooled to below -200°C & fed into a fractional Distillation column. N₂ separated from O₂ & Ar.
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What are emulsifiers?
Substances that help stop emulsions separating.
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How do emulsifiers work?
The hydrophobic parts (attracted to oil) of many emulsifier molecules go into the oil droplet & so the droplets become surrounded by the hydrophilic (attracted to water) parts which keeps them apart in the water (can’t join & separate).
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What is the renewable method for making ethanol?
Fermentation of sugar from plants using yeast –enzymes in yeast convert sugar to ethanol + CO₂ = renewable but must be purified by fractional distillation.
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What is the non-renewable method for making ethanol?
Hydration of ethene –Ethene + steam in a catalyst. Ethene from crude oil (by cracking) = non-renewable & needs high temp but produces pure ethanol.
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Other cards in this set

Card 2

Front

What can Limestone (CaCO₃) be used for?

Back

To make calcium oxide & cement (by mixing CaCO₃ with clay & heating in a kiln). Make concrete by mixing cement with sand, aggregate & water. CaCO₃  CaO + CO₂ . Calcium Carbonate (thermal decomposition) Calcium Oxide + Carbon dioxide

Card 3

Front

How do all metal carbonates react with acids when heated/reacted?

Back

Preview of the front of card 3

Card 4

Front

How do you test for Carbon dioxide?

Back

Preview of the front of card 4

Card 5

Front

What are the main stages involved in the ‘Limestone reaction cycle?”

Back

Preview of the front of card 5
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