Term
| Name two gases produced from a rotary kiln |
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Definition
Any two from:
nitrogen
carbon dioxide
water vapour or steam |
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Term
Which is the better for making columns limestone or concrete with steel rods?
Give 3 advantages of you choice |
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Definition
limestone
• more abundant or local
• natural material requires no ‘processing’
• relatively easy to cut
• better appearance concrete
• raw materials are abundant
Concrete
• can be reinforced by steel rods
• concrete mixture can be poured on site
• less reactive with acid rain or weathering or erosion |
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Term
Balance this symbol equation:
Cu2S + O2 --> CuO + SO2 |
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Definition
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Term
| Why would there be an environmental problem if SO2 was allowed to escape into the atmosphere |
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Definition
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Term
| Descaribe and explain what happens when copper oxide is reduced using carbon |
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Definition
- heat (copper oxide with carbon)
- oxygen is removed by carbon or carbon monoxide / carbon dioxide is produced or carbon displaces copper
- because carbon is more reactive than copper |
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Term
| What is the name of the process used to purify copper |
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Definition
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Term
| What is pure copper used for |
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Definition
electrical wiring
appliances
coins
pipes
cladding for buildings
jewellery
making alloys |
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Term
| Why would recycling copper be better than extracting copper from its ore |
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Definition
- less acid rain caused
- copper reserves last longer or are conserved or do not run out
- energy for extraction is saved
- less mining / quarrying
- less waste copper produced or less landfill |
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Term
| Name the four parts of the earth from the centre out |
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Definition
inner core
outer core
mantle
crust |
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Term
| Why can't scientists accurately predict when earthquakes will occur |
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Definition
| Plate boundaries collide due to convection currents. Convection currents are caused by radioactive processes in the earths crust. Scientists don't know when the pressure will build up under the crust so can't predict when earthquakes will happen |
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Term
| How much nitrogen is there in today's atmosphere |
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Definition
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Term
| What has happened to the levels of oxygen in the earth's atmosphere |
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Definition
oxygen has increased because:
• its released by plants or bacteria
• it is released during photosynthesis |
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Term
| What has happened to the levels of carbon dioxide in the earth's atmosphere in the last 4 million years |
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Definition
carbon dioxide has decreased:
• because it is used by plants or bacteria
• used up during photosynthesis
• ‘locked up’ in (sedimentary) rocks / carbonates / fossil fuels
• becasue it is dissolved in oceans |
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Term
| What do e-numbers indicate on food |
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Definition
| it is a permitted additive |
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Term
| Vegitable oil is shaken with water in a test tube after a while they separate out. What does this mean |
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Definition
| water and oil are immiscible |
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Term
| Explain why vegetable oil and water mix when an aditive is added |
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Definition
| When an emulsifier is added it holds the two components together to form an emulsion by lowering the surface tension |
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Term
| Why does iodine react with vegetable oils |
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Definition
| Vegetable oils are unsaturated because they contain a double carbon carbon bond |
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Term
| Which are the most healthy oils saturated or unsaturated |
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Definition
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Term
| Why is hydrogenated vegetable oil used in soft margarine |
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Definition
| Hydrogenated oils have a higher melting point than vegetable oil. Hydrogenated vegetable oils are solids at room temperature |
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Term
| How are vegetable oils hydrogenated |
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Definition
- hydrogen added
- nickel catalyst
- temperature 60oC |
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Term
| How can ethanol be separated from water |
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Definition
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Term
| Complete the balanced symbol eqaution below for the combustion of fuel: C2H5OH + 3O2 --> 2.... + 3..... |
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Definition
| C2H5OH + 3O2 --> 2CO2 + 3H2O |
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Term
| What process can be used to turn hexane into ethane and ethene |
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Definition
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Term
| How can you turn ethene into ethanol |
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Definition
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Term
| What are the advantages of using sugar to make ethanol |
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Definition
- poor country has no wealth to buy large quantities of crude oil
- can be used by a country that has limited technological development
- countries have suitable climate to grow sugar cane - enough land to grow sugar cane
- sugar is a renewable source
- sugar cane is carbon neutral |
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Term
| What are the advantages of using alkanes to make ethanol |
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Definition
- low economic costs
- continuous process
- country has large oil resources
- country has oil refineries / cracking plants
- very pure product
- faster process |
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