Unit 1b - Oils, Earth And Atmosphere Flashcards
1
Q
What do long chain hydrocarbons form?
A
Thick gloopy liquids like tar
2
Q
What is the process called that turns longer molecules produced from fractional distillation into smaller ones called?
A
Cracking
3
Q
An example of a product from cracking being used as a fuel
A
Petrol for cars or paraffin for jet fuel
4
Q
What other substances are produced in cracking besides fuels and what is its purpose?
A
Ethene. Making plastics.
5
Q
What can you get when you crack disel?
A
Petrol, paraffin and ethene
6
Q
What kind of reaction is cracking?
A
Thermal decomposition
7
Q
How do you crack a long chain hydrocarbon?
A
Heat the long chain hydrocarbons to VAPORISE it then the vapour is passed over a POWDERER CATALYST (aluminium oxide) at a temperature of about 400C - 700C and the long chain molecules SPLIT APART on the surface of the specks of catalyst
8
Q
What does thermal decomposition reaction mean?
A
Breaking molecules down by heating them up
9
Q
What is the catalyst used for cracking?
A
Aluminium oxide
10
Q
What are most of the products of cracking called?
A
Alkanes and Alkenes
11
Q
What is an alternative way to crack the hydrocarbons?
A
Mix the vapour with steam at a very high temperature
12
Q
What is the general word equation for cracking a long chain hydrocarbon?
A
Long-chain hydrocarbon molecule –> shorter alkane molecule + alkene
(Kerosene –> octane + ethene)
13
Q
What is the general formula for an alkane?
A
CnH2n+2
14
Q
What is the general formula for an alkene?
A
CnH2n
15
Q
What does cracking mean?
A
Splitting up long chain hydrocarbons
16
Q
What kind of bond do alkenes have?
A
A C=C double bond
A carbon double bond
17
Q
Why are alkenes known as unsaturated?
A
Because they can make more bonds as the double bond can open up allowing the two carbon atoms to bond with other atoms
18
Q
What are the first two alkenes?
A
Ethene, propene
19
Q
What is the formula for ethene?
A
H H
\ /
C=C
/ \
H H
20
Q
What is the formula for propene?
A
H H H
| | /
H-C-C=C
| \
H H
21
Q
What is the test for an Alkene?
A
Adding the substance to bromine water the Alkene will decolourise the bromine water turning it from orange to colourless.
22
Q
Why does alkenes turn bromine water colourless ?
A
The double bond has opened up and formed bonds with the bromine
23
Q
How can ethene produce ethanol ?
A
It can be hydrated with steam in the presence of a catalyst to make ethanol
24
Q
Why is reacting ethene with steam to produce ethanol cheap!
A
Because ethene is fairly cheap and not much of it is wasted
25
What is the trouble with using ethene to produce ethanol?
Ethene is produced from crude oil which is non renewable that could start running out fairly soon so using ethene to make ethanol will become very expensive in the future
26
What can ethanol be produced from besides ethene?
Renewable resources by fermentation
27
What is the raw material used for fermentation called and how is it converted to ethanol?
Sugar and it is converted into ethanol using yeast
28
What is the word equation for converting sugar into ethanol?
Sugar --> carbon dioxide + ethanol
29
What are the advantages to producing ethanol using fermentation instead of ethene?
It requires a lower temperature, simpler equipment, renewable, used as a cheap fuel in some countries that don't have oil reserves for making petrol
30
Why is sugar a good material to use to make ethanol?
It is grown as a major crop in several parts of the world including many poorer countries
31
What are the disadvantages to making ethanol from fermentation instead of ethene?
The ethanol produced isn't very concentrated so if you want to increase its strength it needs to be distilled (as in whisky distilleries), and it needs to be purified
32
What kind of bonds do Alkanes have?
single carbon bonds
33
What was used before polythene bags?
String bags
34
What can alkenes be used to make?
Polymers
35
What is it called when you join together lots of small alkene molecules to form large molecules?
Polymerisation
36
What is polymerisation?
Joining together lots of small alkene molecules to form large molecules and these long chain molecules are called polymers
37
What are small alkene molecules known as?
Monomers
38
What can may ethene molecules be joined up to form?
Poly(ethene) or polythene
39
What does a polymers structure look like?
```
H H H H H H
| | | | | |
-C-C-C-C-C-C-
| | | | | |
H H H H H H
```
40
What is the general name for a polymer?
Poly(whatever the alkene was)
41
What do you use for polymerisation?
Pressure and a catalyst
42
What do the physical properties of a polymer depend on?
What it's made from
43
What is an example of something stronger than poly(ethene)
Polyamides
44
What are a polymers physical properties affected by?
Temperature and pressure of polymerisation
45
What is characteristics of poly(ethene) made at 200*c and 2000 atmospheres pressure
Flexible with a low density
46
What are the characteristics of poly(ethene) made at 60*c and a few atmospheres pressure with a catalyst
Rigid and dense
47
What are light, stretchable polymers that are used to make plastic bags called?
Low density poly(ethene)
48
What are elastic polymer fibres used to make?
Super stretchy Lycra fibre for tights
49
What are some uses of polymers
Water proof coating force rocks, dental polymers are used in resin tooth filing, polymer hydrogel wound dressings keep wounds moist
50
What are the new biodegradable packaging materials that are being produced made from?
Polymers and cornstarch
51
What is an example of a smart material and what is a smart material?
Memory foam And a polymer that gets softer as it gets warmer and mattresses can be made of memory foam
52
Why are most polymers not biodegradable?
They are unable to be broken down by microorganism so they don't rots and it's difficult to get rid of them
53
What is the best thing to do with polymers that aren't biodegradable?
Re-use them as many times as possible and recycle then otherwise so they'd be in a land fill site for years
54
What are things made from polymers in comparison to those made of metal?
Cheaper
55
Why will the price of crude oil rise and what impact will this have on polymers?
Because crude oil resources get used up so the price of crude oil will rise so will the polymers and one day there el t been ought oil for every use so polymers made using crude oil may not be made
56
What is an example of naturally occurring polymers?
Rubber and silk
57
What are some examples of synthetic polymers?
Polyester and PVC
58
What is an example of a polymer in the body?
DNA
59
What are examples of foods that contain a lot of oil?
Fruits and seeds e.g avocados, olives, Brazil nuts, peanuts and sesame seeds
60
What can oils be used for?
Food or fuel
61
What is the method and its steps to get oil out of fruits and seeds (plants)?
First the plant material is crushed, then press the crushed plant material between metal plates and squash the oil out. Oil can be separated from crushed plant material by a centrifuge (like using a spin dryer to get water out of wet clothes). Or from solvents.
62
What does distillation do to oils?
It refines them and removes water, solvents and impurities
63
Why are vegetable oils used in food?
They provide a lot of energy as they have a high energy content, there are other nutrients in vegetable oils e.g vitamin E and they contain essential fatty acids which the body needs for its metabolic processes
64
Why are vegetable oils good for cooking?
They have a higher boiling point Than water so they can be used to cook foods at a higher temperature and at a faster speed, it gives a different flavour and increases the energy we get from eating the food
65
Why does cooking with oil give a different flavour?
The oils own flavour but also many flavours come from chemicals that are soluble in water so oil carries the flavour making it more intense however it is more fattening
65
How can vegetable oil be used to produce fuel?
Vegetables Oils like Rapeseed oil and soybean oil can be processed and turned into fuels because they provide a lot of energy so they are good for fuels
66
What is biodiesel?
A fuel used from vegetable oils and has similar properties to ordinary diesel fuel as it burns the same way so you can use it to fuel a Diesel engine
67
What is waste oil from manufacturing and cooking in restaurants useful for?
Being used in pet food and cosmetics
68
What is the process called to harden oil?
Hydrogenation
69
What does unsaturated oils contain?
C=C double bonds
70
What are two properties of oils and fats?
They contain long-chain molecules with lots of carbon atoms and they are either saturated or unsaturated
71
What will an unsaturated oil do in bromine water and why?
It will decolourise the bromine water because the bromine opens up the double bond and joins on
72
What do monounsaturated fats contain?
One C=C double bond in Their carbon chains
73
What do polyunsaturated fats contain?
More than one C=C double bond
74
What are unsaturated vegetable oils at room temperature?
Liquid
75
What are the general ways to hydrogenate unsaturated oils?
Reacting them with hydrogen because the hydrogen reacts with the double bonded carbons and opens out the double bond in the presence of a nickel catalyst at about 60*C
76
What are the differences with hydrogenated oils than unsaturated oils?
Have a higher melting point so they are more solid at room temperature so they are useful for spreads and making cakes and pastures
77
What is an example of a partially hydrogenated vegetable oil and why was it only partially hydrogenated?
Margarine and because turning all the double bonds in vegetable oil to single bonds would make margarine too hard and difficult to spread so hydrogenating most of them gives margarine a nice, buttery, spreadable consistency.
78
What are partially hydrogenated vegetable oils often used instead of butter in processed foods and an example?
Biscuits.
Because the oils are must cheaper and butter and they keep longer so they make biscuits cheaper and gives them a long shelf life
79
What is a disadvantage of partially hydrogenating vegetable oils?
You end up with a lot of so-called trans fats which are suggested to be very bad for you
80
What are animal fats generally?
Saturated
81
Why are saturated fats less healthy than unsaturated fats?
Saturated data increase the amount of cholesterol in the blood which can block up arteries and increase the risk of heart disease
82
What do natural unsaturated fats such as olive oil and sunflower oil do?
Reduce the amount of blood cholesterol
83
Why are partially hydrogenated vegetable oils bad for your health?
The trans fats in the increase the amount of cholesterol in the blood so eating lots of them can increase the risk of heart disease
84
What can emulsions be made from?
Lots of little droplets of one liquid suspended in another liquid like oil in water emulsions (oil droplets suspended in water) or water in oil emulsions
85
What are the physical properties of an emulsion and what does that make the suited for?
Thicker e.g mayonaise is thinker than sunflower oil and vinegar and it makes them suited to lots of uses in food e.g salad dressings and sauces as the emulsion coats things better than plain oil or vinegar
86
What makes an emulsion so thick?
The amount of oil in an oil-in-water emulsion
87
Examples of oil-in-water emulsions and percentage of oil?
Milk 3% oil in full fat milk. Single cream 18%. Double cream 50%.
88
What does adding air to an emulsion do and examples of products?
Whipped cream to give it a fluffy frothy consistency for use as a topping. Ice cream to give it a softer texture so it is easier to scoop out.
89
What is an example of a non food related emulsion?
Moisturising lotion because the smooth texture of an emulsion makes it easy to rub into the skin
90
What do some foods contain to help oil and water mix?
Emulsifiers
91
What are emulsifiers?
Molecules with one part that's attracted to water and another part that'd attracted to oil or fat.
92
What is the part in an emulsifier that's attracted to water called?
Hydrophilic
93
What is the part in an emulsifier that is attracted to oil called?
Hydrophobic
94
How do emulsifiers work?
The hydrophilic end of each emulsifier molecule latches onto water molecules where the hydrophobic end attaches to the oil molecule and when you Shake the oil and water and emulsifier together the oil forms droplets surrounded by a coat of emulsifier with the hydrophilic bit facing outwards and other oil droplets are repelled by these hydrophilic bits where the water molecules latch on so they don't separate out again.
95
What are the pros of using emulsifiers?
Stops emulsions from separating out
Gives them a longer shelf life
Allows food companies to produce food low in fat but with a good texture
96
What are the cons of using emulsifiers?
Some people are allergic to certain emulsifiers e.g egg yolk so people have to check the ingredients carefully
97
What did scientists used to think 'wrinkles' in the earths surface was caused by?
The shrinkage of the surface as it cooled down after the earth was formed
98
Who was the person who has the theory of continental drift?
Alfred Wegener
99
How did Wegener start investigating his theory of continental drift?
He came across some work listing the fossils of very similar plants and animals which had been found on opposite sides of the Atlantic Ocean and investigated further finding more examples of it.
100
What did other people who had noticed the similar fossils accept this as?
There has once been land bridges linking the continents so animals has been able to cross but the bridges has sunk or been covered since then
101
What did Wegener notice besides from the fossils?
Coastlines like that of Africa and South America seemed to match like pieces of a jigsaw so he looked for more evidence and found there were matching layers in hthe e the Coke in different continents, fossils were in the wrong places like tropical plants discovered on arctic islands
102
When did Wegener feel like he had enough evidence and published his theory of continental drift?
1915
103
What did Wegener say about the earth in his theory of continental drift?
300 million years ago there was a supercontinent called Pangaea and it broke down into smaller chunks which moved apart and he claimed these chunks - the continents - were slowly drifting apart
104
Why didn't many people accept wegeners theory? (3)
His explanation of how the drifting happened wasn't convincing as he said the continents were ploughing through the sea bed and their movement was caused by tidal forces and the earths rotation, he used inaccurate data in his calculations done made wild predictions of how fast the continents were moving, he wasn't a proper geologist - he sturdiest astronomy
105
Why did other scientists say Wegeners theory of continents moving by tidal forces and the earths rotation was impossible?
Because they calculated the forces needed to move the continents like that would have stopped the earth rotating
106
Why in 1950s were scientists starting to believe wegeners theory?
They were able to investigate the ocean floor and found new evidence (he wasn't right about everything but his main idea was correct)
107
What happened by 1960?
Geologists were convinced of continental drift and beouve the earth is made of several chunks called tectonic plates which move about and collide to push land up to create mountains
108
What are the layers of the earth and their relative sizes?
Crust (very thin between 5k and 50k), the mantle (a lot thicker), core (made of iron and nickel)
109
What is the shape of the earth?
Almost spherical
110
What is the crust surrounded by?
The atmosphere
111
Explain the mantle
It has all the properties of a solid but it can flow very slowly.
112
Where do radioactive decay take place and what happens?
Within the mantle, it produces a lot of head which causes the mantle to flow In convection currents
113
What is the core made of?
Iron and nickel
114
What is the earths surface made up of?
Tectonic plates
115
What are the tectonic plates?
The crust and the upper part of the mantle are cracking into a number of large pieces and this is what they are called
116
Why don't tectonic plates stay in one place?
Convection currents in the mantle cause the plates to drift
117
How far do most of the tectonic plates move each year?
A few cm
118
Why do earthquakes occur?
When the tectonic plates move very suddenly
119
Where do volcanoes and earthquakes often occur?
At the boundary between two tectonic plates
120
Why is it impossible to predict when tectonic plates will move?
Because they can stay more or less put for a while and then suddenly lurch forward
121
What are scientists looking at to see if there are any clues when earthquakes might happen?
Things like strain in under grounds rocks but even then it's only able to say if they are likely not exactly
122
What are the clues that help to decide if a volcanic eruption might happen soon?
Before an eruption molten rock rises up into chambers near the surface causing the ground surface to bulge slightly this causes mini earthquakes near the volcano but sometimes molten rock cools down instead of erupting so mini earthquakes can be a false alarm.
123
What are the percentage and elements in the atmosphere?
78% nitrogen, 21% oxygen and small amounts of other gases like carbon dioxide, noble gases and water vapour
124
What was the first phase of the earth and its atmosphere?
The surface was originally molten so an atmosphere just boiled away. But things cooled down a bit and a thin crust formed but volcanoes continued erupting. The volcanoes gave out lots of gas and that's how oceans and atmosphere were first formed. The atmosphere was probably mostly carbon dioxide and virtually no oxygen, but will water vapour and small amounts of methane and ammonia and when the water vapour condensed oceans formed.
125
What elements were in the very early stages of the atmosphere?
A lot of Carbon dioxide , no oxygen, water vapour, methane and ammonia
126
What was the very early stages of the earths atmosphere a lot like?
The atmosphere of Mars and Venus today
127
What was phase two of the earth and its atmosphere?
Green plants and algae evolved over most of the earth. A lot of the carbon dioxide dissolved into ocean and the green plants absorbed carbon dioxide and produced oxygen by photosynthesis. They died and were buried under layers of sediment along with the skeletons and shells of marine organisms and the carbon and hydrocarbons inside them became locked up in sedimentary rocks as insoluble carbonates and fossil fuels.
128
What happened to the carbon and hydrocarbon inside dead plants and skeletons of marine animals?
It became locked up in sedimentary rock as insoluble carbonates like limestone and fossil fuels
129
What is phase three of the earth and its atmosphere?
The build up of oxygen killed off early organisms that couldn't tolerate it but allowed other more complex organisms to evolve and flourish. The oxygen created the ozone layer which blocked harmful rays from the sun and enabled more complex organisms to evolve and there is virtually no carbon dioxide left.
130
How have we learnt a lot about the past atmosphere and explain the process?
From Antarctic ice cores. Each year a layer of ice forms and bubbles of air get trapped inside then it's buried by the next layer so the deeper the ice the older the air and if you examine the bubbles you can see how the air has changed
131
What is the primordial soup theory on how life formed?
1. Billions of years ago the earths atmosphere was rich in nitrogen, hydrogen, ammonia and methane
2. Lightening struck causing a chemical reaction between the gases resulting in the formation of amino acids
3. The acids collected in a 'primordial soup' - a body of water out of which life gradually crawled out
4. The acids gradually combined to produce organic matter which evolved into living organism
132
What did Miller and Urey do to try and prove the primordial soup theory?
They sealed the gases in their apparatus, heated them, and applied an electrical charge for a week
133
What did Miller and Urey find from their experiment and what does this suggest?
That amino acids were made but not as many as there are on earth so the theory could be along the right lines but isn't quite right
134
What is the ultimate source of minerals and resources?
The earths crust, oceans and atmosphere
135
What do you do to air to get a variety of products like nitrogen and oxygen?
Fractionally distill it
136
What are the steps to fractionally distill air?
1. Air is filtered to remove dust
2. It's then cooled to -200*c to a liquid
3. When cooled water vapour condenses and is removed
4. Carbon dioxide freezes and is removed
5. The liquified air then enters the fractionating column and is heated slowly
6. Remaining gases are separated by fractional distillation but oxygen and argon come out together so another column is used to separate them
137
What does increasing carbon dioxide levels affect?
The climate and the ocean
138
What does burning fossil fuels do?
Releases carbon dioxide
139
What does the increase in carbon dioxide cause?
Global warming which is a type of climate change
140
Why does the increase in carbon dioxide levels mean a bad thing for the ocean?
They naturally store carbon dioxide as they absorb it for mother atmosphere but the extra carbon dioxide is too acidic which is bad for coral and shellfish and in the future they won't be able to absorb any more carbon dioxide
