Term
| Why is cracking of hydrocarbons so important? |
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Definition
| We make smaller, more useful molecules from the bigger ones |
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Term
| How is cracking carried out? |
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Definition
| Heat strongly and pass over catalyst |
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Term
| Alkenes are unsaturated hydrocarbons because they contain............... |
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Definition
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Term
| Unsaturated hydrocarbons react with Bromine water. What happens and Why? |
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Definition
| The bromine water is decolourised because the bromine reacts with the alkene to break the double bond |
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Term
| Name 3 ways we use hydrocarbon-based fuels |
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Definition
| Transport, heating, generating electricity |
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Term
| What are the small molecules that make a polymer called? |
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Definition
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Term
| Is ethene and alkene or alkane? |
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Definition
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Term
| What is the general formula of a alkane? |
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Definition
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Term
| When monomers join together, the process is called........ |
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Definition
| ..........addition polymerisation |
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Term
| Name the polymer made from propene |
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Definition
| polypropene (sometimes polypropylene) |
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Term
| How are the atoms in polymer chains held together? |
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Definition
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Term
| The forces between polymer chains are called........ |
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Definition
| .....Intermolecular forces |
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Term
| Describe the features of a thermsoftening plastic |
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Definition
| Soften easily when heated as intermolecular forces are weak. Can be reshaped |
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Term
| PET is a plastic used for pop bottles. Give three reasons for using it |
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Definition
| 1. Strong 2. Can be made see-through 3. Lightweight so cheaper to transport |
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Term
| Give an example of a smart polymer and describe what it does |
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Definition
| Shape memory polymer used as stitches in a wound. Body heat warms the polymer so it contracts pulling the skin edges together |
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Term
| Word equation for photosynthesis |
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Definition
| Water + Carbon dioxide ---> Glucose + Oxygen. Sunlight provides the energy |
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Term
| Two ways to extract oils from plants and an example of each |
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Definition
Pressing - olives
Distillation - lavender oil |
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Term
| Why are unsaturated vegetable oils usually liquids? |
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Definition
| Because the double bonds stop the molecules fitting neatly together |
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Term
| Liquid oils can be hardened by addition of hydrogen. What are the conditions for this process? |
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Definition
| 60 degrees Celsius and a Nickel Catalyst |
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Term
| What does an emulsifier do? |
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Definition
| Stops oil and water from separating |
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Term
| Three examples of emulsions we eat/drink |
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Definition
| Mayonnaise, Ice cream, Milk |
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Term
| How are food additives identified on packaging? |
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Definition
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Term
Why do we use the following additives?
1. Colouring
2. Preservatives
3. Antioxidants
4. Emulsifiers
5. Acidity regulators
6. Flavourings |
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Definition
1. Improves appearance
2. Helps food keep longer
3. Stops food reacting with Oxygen
4. Improves texture
5. Controls pH
6. Changes the flavour |
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Term
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Definition
| Any fuel made from vegetable oils |
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Term
| Why is ethanol made from sugar classed as a bio-fuel but if made from ethene is not? |
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Definition
| Sugar is a natural plant source but ethene comes from cracking of crude oil which is a fossil fuel. |
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Term
| Name the four main divisions of the Earth's structure |
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Definition
Outside --> Inside
Crust, Mantle, Outer core, Inner core |
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Term
| Give another name for the Earth's crust |
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Definition
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Term
| The theory of continental drift was put forward in 1915 by...... |
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Definition
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Term
| What makes the tectonic plates move? |
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Definition
| Convection currents, in the mantle, caused by heating due to radioactive decay |
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Term
| What was the main gas in the Earth's earliest atmosphere? |
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Definition
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Term
| How was the Earth's earliest atmosphere formed? |
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Definition
| Gases emitted by volcanoes |
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Term
| Name the components of the atmsophere now and quote percentages |
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Definition
Nitrogen 78%
Oxygen 21%
Argon 0.9%
Carbon dioxide 0.04% (rising)
Other gases Trace% |
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Term
| Why has the carbon dioxide level in the Earth's atmsophere risen so much in recent years? |
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Definition
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