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67 Cards in this Set
- Front
- Back
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hat do elements which are in the same group have in common?
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Same number of electrons in the outer shell.
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What does the atomic number tell you?
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Number of protons. (and electrons)
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What is an ionic bond?
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–Compound formed between a metal and a non–metal.
–Give electron. –Made of ions. |
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What is a covalent bond?
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–Share electrons.
–Between non–metals. –Made of molecules. |
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What does limestone thermally decompose into?
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Calcium oxide + Carbon dioxide
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Why might you have trouble doing some of the thermal decomposition reactions for magnesium, sodium and zin carbonates?
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–Not hot enough in the bunsen burner.
–Group 1 metals especially. |
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What happens when an acid reacts with limestone? (CaCO3)
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Calcium salt + Carbon dioxide + Water
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What is used to neutralise acidic soil?
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Calcium hydroxide.
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How is calcium hydroxide made?
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Calcium oxide + Water
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What makes limewater turn cloudy?
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Calcium carbonate.
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What is used as a test for carbon dioxide?
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Calcium hydroxide.
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How can you make cement?
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Powdered limestone heated with powdered clay.
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How do you make mortar?
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Cement mixed with sand and water.
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How do you make concrete?
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Mix cement with sand and aggregate.
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Name 3 uses of limestone.
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–Neutralise sulphur dioxide in power station chimneys.
–Neutralise acidic soil. –Build roads and houses ect. |
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Name a secondary (positive) impact of limestone quarrying.
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Provides jobs and helps the local economy.
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What is a metal ore?
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A rock which contains enough metal for it to be worth extracting from it.
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Name the 2 ways a metal can be extracted from their ore.
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–Electrolysis
–Reduction |
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Which metals can be extracted by reduction with carbon?
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Zinc and below
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Why can carbon only react with things below zinc?
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Because CARBON can only take the oxygen away from metals which are less reactive than itself.
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When is electrolysis used to extract metals from their ores?
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When the metal is higher in the reactivity series than CARBON.
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How can we purify metals?
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Electrolysis.
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How are ions turned to atoms during electrolysis?
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The electrolyte provides electrons.
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Name 2 new methods of extracting copper from its ore.
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–Phytomining
–Bioleaching |
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How does bioleaching work?
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–Uses bacteria to separate copper from copper sulphate.
–The leachate contains copper which can be extracted. |
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Describe phytomining.
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–Grow plants in a copper rich soil.
–It builds up in the leaves because they cant use it. –Plants are harvested, dried and burned. –Copper is collected from the ash |
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Name 3 properties of copper.
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–Good conductor of electricity
–Hard, strong, bendable –Doesn't react with water |
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Name 4 properties of aluminium.
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–Corrosion resistant
–Low density –When pure its not very strong but forms hard, strong alloys |
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Name 3 properties of titanium.
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–Low density
–Very strong –corrosion resistant |
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What is the general formula for alkanes
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N2H2n+2
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What does volatile mean?
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The temperature at which a substance turns into a gas.
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What 3 characteristics will shorter molecules have?
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–Not very viscous
–Very volatile –Flammable |
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When could oil be gone?
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25 years
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How is acid rain formed?
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Sulphur dioxide mixes with clouds to form sulphuric acid.
(Oxides of nitrogen can do the same) |
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how can we reduce sulphur emissions?
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–Remove it from the fuel before burning
–Use less fossil fuel –The use of Acid Gas scrubbers in factories |
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What is the argument of people who don't believe that climate change is real?
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Inaccurate measuring equipment
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Talk about the pros and cons of using ethanol as a fuel.
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Pros:
–Carbon neutral Cons: –Engines need converting –Isn't widely available –Possible food price increase |
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Talk about the pros and cons of using biodiesel as a fuel.
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Pros:
–Carbon neutral –No engine conversion –Much less sulphur dioxide and particulates Cons: –Cant make enough to replace diesel –Increase food prices |
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Talk about the pros and cons of using Hydrogen gas as a fuel.
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Pros:
–Hydrogen combines with O2 in the air to just make water (clean) Cons: –Need a special, expensive engine –Need electricity for the electrolysis to make hydrogen. |
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What kind of reaction is cracking?
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Thermal decompostition
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Explain the process of cracking long chain hydrocarbons.
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1) Heat the long chain hydrocarbon to vaporise it.
2) Pass the vapour over a powdered catalyst at a temp of around 400 to 700 degrees centigrade. 3) Aluminium oxide is the catalyst used. 4) The long chain molecules crack on the surface specks of the catalyst. |
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What are alkenes?
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Hydrocarbons with a double bond between two of the carbon atoms.
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What is the general formula of an alkene?
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CnH2n
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How can you test for an alkene?
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– Add it to bromine water. It would turn it from orange to colourless.
– This is because the double bond has broken up and formed bonds with the bromine. |
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Name the first 2 alkenes.
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Ethene
Propene |
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How can we make ethanol?
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Hydrate ethene with steam in the presence of a catalyst.
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Why is making ethanol with steam probably going to become expensive?
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Ethene is produced from crude oil.
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Say the word equation for the renewable way of making ethanol.
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Sugar ––––––> Carbon dioxide + ethanol
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Say 3 advantages and 1 disadvantage of the renewable way of making ethanol.
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+ Lower temp.
+ Renewable so wont run out. + Can be used as a cheap fuel for poor countries. – Not very concentrated so have to distil it. |
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What is the process where you join together small alkene molecules to form large molecules called polymers called?
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Polymerisation
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What process will make denser and more rigid plastics?
(A) 200 degrees C and 2000 atmospheres (B) 60 degrees C and few atmospheres pressure with a catalyst. |
(B) 60 degrees C and few atmospheres pressure with a catalyst.
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Describe the 3 methods for plant oil extraction.
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– Press the plant
– Separate oil by a centrifuge – Solvents |
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What kind of chain are oils and fats made from?
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Long–chain with lots of carbons.
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What kinds of fats contain double bonds between carbons?
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Unsaturated. So they will discolour bromine water.
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How do you hydrogenate an unsaturated vegetable oil?
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React with hydrogen at 60 degrees C in the presence of a nickel catalyst.
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What makes hydrogenated fats good for use as margarine?
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Higher melting point so more solid at room temp.
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Are vegetable oils or animal fats unsaturated?
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Vegetable oils.
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Name 2 disadvantages and 1 advantage of using emulsifiers.
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+ Longer shelf life.
+ Low fat but still good texture. –Some people are allergic to them (egg yolk). |
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Who had the theory of continental drift?
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Wegener
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Why didn't people accept Wegener's theory?
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He made some calculations (about speed of drift) which made other scientists think that it as impossible.
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What is the core made of?
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Iron and nikel
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How much nitrogen and oxygen does our atmsphere consist of?
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78% nitrogen
21% oxygen |
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What happened in phase 1?
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– Volcanoes gave out gasses.
– Especially CO2. – Like Mars and Venus today. – Oceans formed when water vapour condenced. |
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What happens in phase 2?
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– Green plants evolved and produced oxygen.
– The CO2 dissolved in the oceans. |
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What happens in phase 3?
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– Ozone layer builds up with oxygen which allows the development of more complex organisms.
– Much less CO2 left now |
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Explain the primordial soup theory.
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– Billions of years ago the atmosphere was rich with nitrogen, hydrogen, ammonia and methane.
– Lightning struck causing the gasses to react forming amino acids. – The amino acids collected in a primordial soup. – The amino acids gradually combined to make organic matter and finally living organisms. |
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What is a problem with the primordial soup theory?
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Some scientists tried it and they could only produce a few of the amino acids found on earth.
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