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67 Cards in this Set
- Front
- Back
What do elements which are in the same group have in common? |
Same number of electrons in the outer shell. |
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What does the atomic number tell you? |
Number of protons. (and electrons) |
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What is an ionic bond? |
-Compound formed between a metal and a non-metal. -Give electron. -Made of ions. |
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What is a covalent bond? |
-Share electrons. -Between non-metals. -Made of molecules. |
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What does limestone thermally decompose into? |
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? |
-Not hot enough in the bunsen burner. -Group 1 metals especially. |
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What happens when an acid reacts with limestone? (CaCO3) |
Calcium salt + Carbon dioxide + Water |
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What is used to neutralise acidic soil? |
Calcium hydroxide. |
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How is calcium hydroxide made? |
Calcium oxide + Water |
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What makes limewater turn cloudy? |
Calcium carbonate. |
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What is used as a test for carbon dioxide? |
Calcium hydroxide. |
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How can you make cement? |
Powdered limestone heated with powdered clay. |
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How do you make mortar? |
Cement mixed with sand and water. |
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How do you make concrete? |
Mix cement with sand and aggregate. |
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Name 3 uses of limestone. |
-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. |
Provides jobs and helps the local economy. |
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What is a metal ore? |
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. |
-Electrolysis -Reduction |
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Which metals can be extracted by reduction with carbon? |
Zinc and below |
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Why can carbon only react with things below zinc? |
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? |
When the metal is higher in the reactivity series than CARBON. |
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How can we purify metals? |
Electrolysis. |
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How are ions turned to atoms during electrolysis? |
The electrolyte provides electrons. |
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Name 2 new methods of extracting copper from its ore. |
-Phytomining -Bioleaching |
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How does bioleaching work? |
-Uses bacteria to separate copper from copper sulphate. -The leachate contains copper which can be extracted. |
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Describe phytomining. |
-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. |
-Good conductor of electricity -Hard, strong, bendable -Doesn't react with water |
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Name 4 properties of aluminium. |
-Corrosion resistant -Low density -When pure its not very strong but forms hard, strong alloys |
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Name 3 properties of titanium. |
-Low density -Very strong -corrosion resistant |
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What is the general formula for alkanes |
N2H2n+2 |
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What does volatile mean? |
The temperature at which a substance turns into a gas. |
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What 3 characteristics will shorter molecules have? |
-Not very viscous -Very volatile -Flammable |
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When could oil be gone? |
25 years |
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How is acid rain formed? |
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? |
-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? |
Inaccurate measuring equipment |
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Talk about the pros and cons of using ethanol as a fuel. |
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. |
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. |
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? |
Thermal decompostition |
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Explain the process of cracking long chain hydrocarbons. |
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? |
Hydrocarbons with a double bond between two of the carbon atoms. |
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What is the general formula of an alkene? |
CnH2n |
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How can you test for an alkene? |
- 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. |
Ethene Propene |
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How can we make ethanol? |
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? |
Ethene is produced from crude oil. |
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Say the word equation for the renewable way of making ethanol. |
Sugar ------> Carbon dioxide + ethanol |
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Say 3 advantages and 1 disadvantage of the renewable way of making ethanol. |
+ 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? |
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. |
- Press the plant - Separate oil by a centrifuge - Solvents |
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What kind of chain are oils and fats made from? |
Long-chain with lots of carbons. |
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What kinds of fats contain double bonds between carbons? |
Unsaturated. So they will discolour bromine water. |
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How do you hydrogenate an unsaturated vegetable oil? |
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? |
Higher melting point so more solid at room temp. |
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Are vegetable oils or animal fats unsaturated? |
Vegetable oils. |
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Name 2 disadvantages and 1 advantage of using emulsifiers. |
+ 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? |
Wegener |
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Why didn't people accept Wegener's theory? |
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? |
Iron and nikel |
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How much nitrogen and oxygen does our atmsphere consist of? |
78% nitrogen 21% oxygen |
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What happened in phase 1? |
- 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? |
- Green plants evolved and produced oxygen. - The CO2 dissolved in the oceans. |
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What happens in phase 3? |
- 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. |
- 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? |
Some scientists tried it and they could only produce a few of the amino acids found on earth. |