C1 Atoms And Products From Rocks and oil. Flashcards
What does the top number on a periodic table symbol mean?
The mass number. The total number of protons and neutrons.
What is an element?
A thing made of only one type of atom.
What does the bottom number on a periodic table symbol mean?
It is the atomic number. This is the number of protons which also tells you the number of electrons.
How do you find the number of neutrons of an atom?
Subtract the atomic number from the mass number.
Why are ions attracted to each other?
They from an ionic bond as they are of opposite charges and so are attracted to each other.
What is a compound that forms from two non-metals?
A covalent bond.
What is limestone?
Calcium carbonate. CaCO”3”
What happens when calcium carbonate thermal decomposes?
Calcium carbonate = calcium oxide + carbon dioxide.
CaCO”3”. CaO. CO”2”
What happens when magnesium, copper, zinc or sodium carbonates are heated?
They will thermally decompose in the same way calcium will.
What happens when calcium carbonate is reacted with acid?
A salt, CO2 and water will be made.
Calcium carbonate+ sulphuric acid=calcium sulphate + CO2+H2O
CaCO”3”. H”2”SO”4”. CaSO”4”
The salt created will depend on the acid used.
What happens when water is added to calcium oxide?
CaO + H”2”O = Ca(OH)”2”
Calcium hydroxide will be made.
What can calcium hydroxide be used for?
It is an alkali so it can be used to neutralise acidic soil in fields. Powdered limestone can be used for this as well but the hydroxide works faster.
Also, if it is mixed with water you get limewater which can detect CO2
What happens when calcium hydroxide is mixed with carbon dioxide?
Calcium hydroxide + CO”2” = calcium carbonate + water.
Ca(OH)”2”. CaCO”3”. H”2”O
How can limestone be used in construction?
Powered limestone is heated in akin with powdered clay to make cement.
Cement can be mixed with sand and water to make mortar. Mortar is the stuff used to stick bricks together. Calcium hydroxide can also be used.
Or cement can be mixed with sand and aggregate to make concrete.
What is a problem with quarrying limestone?
It makes huge ugly holes which alter the landscape.
Quarrying processes make lots of noise and dust in quiet scenic areas.
It destroys the habitats of animals and birds.
The limestone needs to be transported away. This causes noise and pollution.
Waste materials produce un slightly tips.
How does using limestone cause pollution?
Cement factories make a lot of dust which can cause breathing problems.
Energy is needed to produce cement and quicklime. The energy will come from burning fossil fuels.
What are the positives of mining limestone?
It can be used to build things.
Limestone can be used to neutralise acidic soil or acidic rivers.
It it neutralise sulphur dioxide which is produced by power stations.
Quarrying provides jobs and adds money to the local economy.
Landscaping and restoration of the area is normally required as part of the planning persission.
What are the pros of using limestone?
It is widely available and cheaper than granite or marble. It is easy to cut.
It looks attractive and can be more hard wearing than marble.
Concrete can be poured into moulds to make blocks. It is quick and cheap but very un attractive.
It’s fire resistant, doesn’t rot and can’t be gnawed by animals.
Concrete doesn’t corrode. It has a very low tensile strength which can be improved by steel bars.
What is an ore?
A rock with enough of an element in it for it be economically viable to extract it.
How can the economics of metal extraction change?
If the market price drops, it might not be worth extracting it.
If the price goes up, it might be worth extracting more of it.
As technology improves it can make extracting metal cheaper.
How can a metal be extracted from an ore?
It can be done chemically by reduction or by electrolysis.
Some ores may have to be concentrated before extraction.
Electrolysis can be used to purify the extracted metal.
How can some metals be extracted by reduction with carbon?
Oxygen will be removed from the ore.
2Fe”2”O”3” + 3C = 4Fe + 3CO”2”
The Metals will have to be less reactive than carbon for this to work.
Why is electrolysis used to extract certain metals?
They are more reactive than carbon so can’r be displaced.
Why is copper purified with electrolysis?
It is extracted with reduction with carbon when it is smelted.
However this isn’t very pure.
It is electrolysed so as to purify it so it is a better conductor.
What is electrolysis?
The breaking down of substances using electricity.
Describe electrolysis.
It requires a liquid to conduct the electricity, called the electrolyte.
They are often metal salt solutions made from the ore or molten metal oxides.
The electrolyte has free ions which means it conducts electricity.
Electrons are taken away by the anode and given by the cathode. As ions gain or lose electrons they become atoms or molecules and are released.
How is copper extracted by electrolysis?
Electrons are pulled off copper atoms at the anode causing them to go into the solution as Cu 2+ ions.
Cu2+ ions near the cathode gain electrons and turn back into the copper atoms.
The impurities are dropped at the anode as sludge, whilst pure copper atoms bond to the cathode.
The anode is a lump of impure copper which gets dissolved.
The cathode starts as a thin piece of pure copper which gets bigger.
What happens if reactive metals are out into a solution of a dissolved metal compound?
Give an example.
The more reactive metal will replace the less reactive metal in the compound.
Scrap iron is put in a copper sulphate. Copper metal and iron sulphate will be produced.
How can copper be extracted from low grade ores?
What are the pros and cons of these methords?
Bio leaching and phytomining. They damage the environment less but they are slow.
How does bio leaching work?
Bacteria separates copper from copper sulphide. The bacteria get energy from the bond between copper and sulphur, separating out the copper from the ore in the process. The leachate (solution produces) contains more copper which can be extracted.
How does phytomining work?
Plants are grown in copper rich soil.
The copper gets built up in the leafs. The plants can be harvested dried as burned in a furnace.
The copper can be collected from the ash.
Why is recycling metal important?
Making and extracting metals takes energy which comes from fossil fuels.
Fossil fuels are running out so its important to conserve them. Also using them causes global dimming and global warming. Recycling metal uses only 15% of the energy used to mine more.
It is cheaper.
There is a finite amount of metal in the Earth.
Recycling means less goes into land fill.
What are the properties of copper?
It is a good conductor of electricity so it is good for electrical wires. It’s hard and strong but can be bent. It doesn’t react with water.
Used in plumbing.
What are the properties of aluminium?
It is corrosion resistant and has a low density. It can form hard strong alloys.
Used in planes.
What are the properties of titanium?
Low density metal and unlike aluminium it’s very strong.
It is also corrosion resistant.
Used in replacement hips.
What are the problems of using metals?
they can corrode when exposed to air and water. They need to be protected by painting. If they can lose strength and hardness in this way.
Also when stresses and strains are repeatedly put on metal it suffers from metal fatigue.
What is the problem of metal that comes from the blast furnace?
It is 96% iron and 4% carbon.
This is cast iron. It is used in manhole covers but it doesn’t have many other uses as it is brittle.
If all the iron is removed, the layers of atoms can slide over each other and it is too soft.
What is low carbon steel used for?
What is is made of?
0.1% carbon. It is easily shaped and used in car bodies.
What is high carbon steel used for?
What is is made of?
1.5% carbon. Very hard and inflexible. Used for cutting blades and bridges.
What is stainless steel used for?
What is is made of?
Contains chromium and some nickel. Corrosion resistant. Used for cutlery containers of corrosive substances.
Why are alloys harder than pure metals?
They contain different sized atoms. This changes the arrangement meaning they can’t slide over each other.
What is bronze made of?
Copper and tin. It is harder than bronze and is used for metals and statues.
What is cupronickel made from?
What are the properties?
What is it used for?
Copper and nickel. Hard and corrosion resistant. Used in silver coins.
What are gold alloys made of?
Zinc, copper, silver, palladium and nickel are add to make gold harder.
What is a mixture?
Two or more elements or compounds that aren’t chemically bonded.
What is crude oil made from?
A mixture of hydrocarbons. No bonds between them so they can be separated by fractional distillation.
From bottom to top, what is realised by a fractional distillation coloumn?
Bitumen (used for roads) oil, diesel, kerosene(jet fuel) naphtha, petrol and refinery gas.
What are first five alkanes?
Methane, ethane, propane, butane, pentane.
What are alkanes?
Chains of carbon atoms surrounded by hydrogen atoms. They are the fractions of crude oil.
What is the general formula for alkanes ?
C”n”H”2n+2”
As the length of alkanes decreases, what happens to the properties?
It will become less viscous, more volatile and flammable.
What can alkanes be use for?
It can be used as a fuel in the form or gas or petrol.
Very viscous ones are used as engine lubricants and for covering roads.
Why is crude oil used so much?
It makes a good fuel and can be used in vehicles, power stations or heating systems.
They can provide plastics and chemicals.
Everything is set up to run on store and sell crude oil.
It is a more reliable source of energy than renewable sources.
How does crude oil damage the environment?
It causes oil spills. Birds get covered in it and are poisoned as they try to clean themselves. Other creatures are also killed.
Burning it causes acid rain, global warming and dimming.
When might the oil run out?
It may be gone in 25 years but new oil is being found.
What gases are produced by using fossil fuels?
Hydrocarbon + oxygen = carbon dioxide + water vapour.
If the fuel contains sulphur impurities sulphur dioxide will be produced.
Oxides of nitrogen will form is it gets hot enough.
Partial combustion will happen if there isn’t enough oxygen. Some of the fuel won’t be burnt and this mixed with carbon will be produced. Carbon monoxide will be produced.
How does acid rain work?
Sulphur dioxide or oxides of nitrogen are produced by industry.
These will mix with clouds and form weak acids.
Acid rain kills tres, damages limestone buildings and statues.
How can acid rain be prevented?
Most of the sulphur can be removed from the fuels before they’re burnt but it’s expensive.
Removing the sulphur takes energy which comes from fossil fuels.
Petrol and diesel are being replaced with low sulphur versions.
Power stations have acid gas scrubbers that take out harmful gases before they are released into the air.
Use less fossil fuels.
Explain global dimming.
In some areas there is 25% less sun light and this is global dimming.
Particles of soot and ash are produced when fossil fuels are burnt. These block out the sun.
Name three alternatives to fossil fuels.
Biodiesel, hydrogen gas and ethanol.
How is ethanol produced?
Plant material is fermented and ethanol is produced. Or can be mixed with petrol.
How is biodiesel produced?
It comes from vegetable oils like rapeseed oil and soybean oil. It can be mixed with normal diesel.
How is hydrogen produced?
Water is electrolysed.
What are the pros of ethanol?
Is is carbon neutral. The only other thing produced is water.
What are the pros of biodiesel?
Carbon neutral.
Cars don’t need to be converted. It produced less sulphur diocese and particulates than ordinary fuel.
What are the pros of hydrogen gas?
It is very clean. Only water is produced.
What are the cons of ethanol?
Engines have to converted to run on it. It isn’t widely available. It could increase food prices.
What are the cons of biodiesel
We can’t make enough to replace diesel. It expensive and could increase food prices.
What are the cons of hydrogen gas?
Not widely available.
Hard to store.
Special engines are needed.
Energy is needed to make it.
Define atom.
Smallest particle that still has chemical properties.
Define compound.
Materials with more than one type of atom bonded.
How is copper extracted from high grade ore?
Smelting.
What is a distinctive feature of alkanes?
They only have single bonds. Saturated.
What is the formula for sulphur dioxide?
SO”2”
What does a catalytic converter do?
The combine the poisons carbon monoxide and nitrogen oxide and turn them into harmless nitrogen and less harmless carbon dioxide.
Why can disposing of rock when mining from low grade ores be a problem?
The is a lot of rock to get rid of.
Why might it be hard to recycle something like a pen?
It contains many different polymers and it would cost money to separate them all.
Other than improved strength, what is an advantage of alloys?
They can be less reactive. Like stainless steel.
Why is neon in the same group as helium?
The both have a full outer shell.
Don’t say the have the same number of electrons on the outer shell.
What is considered a large amount of crude oil in an oil well?
10-15%
Why is extracting titanium expensive?
Can’t reduce with carbon.
Lots of energy.
Lots of stages.
Why is argon used when smelting titanium?
To stop magnesium reacting with nitrogen and oxygen from the air.
What is the main gas that comes out of a rotary kiln?
Nitrogen as the air is around 78% nitrogen.
