CHEMISTRY UNIT 1
- Created by: slr674
- Created on: 18-09-14 17:01
View mindmap
- Chemistry
- Earth's atmosphere
- Nitrogen 78%
- Oxygen 21%
- Continental drift
- Alfred Wegener
- Theory of crustal movement
- Earth's land once joined together = "supercontinent"
- Broke up over millions of years ago = land masses moved apart
- Earth's land once joined together = "supercontinent"
- Before, scientists thought features on worlds surface were caused by shrinking
- 1.Earth cooled after it was formed
- 2.Its crust shrank and wrinkled to form mountains
- based on observations involving SOUTH AMERICA and AFRICA
- NO evidence to show how continents could move
- Theory of crustal movement
- Alfred Wegener
- Earth's structure
- Crust
- Thinnest layer
- Mantle
- Thick layer between crust and core
- Core
- Radius is just over half of Earth's radius
- Moving plates
- tectonic plates move a few centimetres a year
- Move because of CONVECTION CURRENTS in mantle
- CURRENTS driven by HEAT from natural RADIOACTIVE processes in Earth
- Earth movements can be sudden making it difficult to predict WHEN earthquakes will happen
- Plates collide or push against each other, sudden movements happen causing earthquakes
- Crust
- Hardening plant oils
- Unsaturated vegetable oils have double bonds
- Polyunsaturated oils have lots of double bonds
- Unsaturated oils better for health
- Bromine Water is orange
- Turns colourless when mixed with UNSATURATED substance.
- Double bonds change to singular bonds
- More double bonds = more bromine water can be added before becomes colourless
- Double bonds change to singular bonds
- Turns colourless when mixed with UNSATURATED substance.
- Hardened veg. oils described as HYDROGENATED
- Less unsaturated than oils used to make them
- higher melting point than original oils
- Solid at room temp.
- Used to make margerine
- Useful in cakes and pasteries
- higher melting point than original oils
- How are vegetable oils hardened?
- Hydrogen added to oil at 60°C with nickel catalyst, adds hydrogen to the C=C double bond
- Why are vegetable oils hardened?
- Hardened vegetable oils have high melting points, so stay solid at room temperature. This means they can be used in cakes/pasteries/margarine
- Less unsaturated than oils used to make them
- Unsaturated vegetable oils have double bonds
- Emulsions
- If oil and water shaken together, they form EMULSION
- Emulsions are:
- thicker (more viscous)
- have better texture and appearance
- This makes them useful for paints, salad dressings, ice cream and cosmetics
- thicker (more viscous)
- have better coating ability (stick to food/other objects better)
- This makes them useful for paints, salad dressings, ice cream and cosmetics
- have better coating ability (stick to food/other objects better)
- Emulsions are:
- Hydrophilic = water loving
- Head = dissolves in water
- Hydrophobic = water hating
- tail = dissolves in oil
- Why are emulsions useful in household paints?
- emulsions have good coating ability, so stick to walls well
- QUESTIONS
- Why does a layer of olive oil form on top of vinegar after a while?
- Oil does not dissolve in vinegar (which is mostly water) and oil is less dense than water
- Why is egg yolk an ingredient in many salad dressing?
- Egg yolk contains an emulsifier which stabilises the emulsion (stops the oil and vinegar seperating)
- Why does a layer of olive oil form on top of vinegar after a while?
- QUESTIONS
- Why does a layer of olive oil form on top of vinegar after a while?
- Oil does not dissolve in vinegar (which is mostly water) and oil is less dense than water
- Why is egg yolk an ingredient in many salad dressing?
- Egg yolk contains an emulsifier which stabilises the emulsion (stops the oil and vinegar seperating)
- Why does a layer of olive oil form on top of vinegar after a while?
- If oil and water shaken together, they form EMULSION
- Vegetable oils
- 1. Steam distillation
- Water is boiled =STEAM
- STEAM passes through the PLANT MATERIAL
- STEAM carries OIL away
- The mixture or STEAM and OIL is COOLED
- OIL floats on condensed steam
- The mixture or STEAM and OIL is COOLED
- STEAM carries OIL away
- STEAM passes through the PLANT MATERIAL
- 2 ways that oils can be extracted from SEEDS, NUTS and FRUITS
- 2. Pressing and filtering
- Plant material must be CRUSHED to release oil and water from the plant cells
- The oil floats on top of the water and crushed plants
- Crushed plant material may need to be PRESSED to remove oil
- Crushed plant material can be removed by FILTRATION
- Oil and water are separated to make a useful product
- Crushed plant material can be removed by FILTRATION
- Crushed plant material may need to be PRESSED to remove oil
- The oil floats on top of the water and crushed plants
- Plant material must be CRUSHED to release oil and water from the plant cells
- 2. Pressing and filtering
- Water is boiled =STEAM
- 2. Pressing and filtering
- Plant material must be CRUSHED to release oil and water from the plant cells
- The oil floats on top of the water and crushed plants
- Crushed plant material may need to be PRESSED to remove oil
- Crushed plant material can be removed by FILTRATION
- Oil and water are separated to make a useful product
- Crushed plant material can be removed by FILTRATION
- Crushed plant material may need to be PRESSED to remove oil
- The oil floats on top of the water and crushed plants
- Plant material must be CRUSHED to release oil and water from the plant cells
- Vegetable oils have higher boiling points than water...
- ... This means oil:
- cooks at higher temps
- cooks faster than water
- has different FlaVouRS
- DOESN'T release more energy when it is eaten
- ... This means oil:
- 1. Steam distillation
- Ethanol
- this is the alcohol in alcoholic drinks
- it is also a fuel and it has industrial and chemical uses
- How to produce your own ethanol:
- 1. HYDRATION OF ETHENE, most ethanol for industrial use is made by this way
- Ethene and steam react together in the presence of a catalyst to make...
- ...ETHANOL!!!
- Ethene and steam react together in the presence of a catalyst to make...
- 2.Fermentation is a natural process
- Use yeast ( a type of microorganism) to convert sugar from plants into ethanol
- sugar - ethanol + carbon dioxide
- Use yeast ( a type of microorganism) to convert sugar from plants into ethanol
- 1. HYDRATION OF ETHENE, most ethanol for industrial use is made by this way
- What does one see during fermentation?
- bubbles!
- this is the alcohol in alcoholic drinks
- Earth's atmosphere
- 2.Fermentation is a natural process
- Use yeast ( a type of microorganism) to convert sugar from plants into ethanol
- sugar - ethanol + carbon dioxide
- Use yeast ( a type of microorganism) to convert sugar from plants into ethanol
Comments
No comments have yet been made