Unit 1 Flashcards
(222 cards)
1
Q
Where are protons and neutrons found in the atom?
A
Nucleus
2
Q
Where are electrons found in an atom?
A
They orbit the nucleus
3
Q
What does the atomic number tell you?
A
The number of protons
4
Q
What does the mass number show?
A
The number of protons and neutrons
5
Q
What does the group number show?
A
The number of electrons in the outer shell
6
Q
Why are noble gases unreactive?
A
They have a full outer shell
7
Q
What is the general formula for the saturated compound?
A
CnH2n+2
8
Q
What is the general formula for the unsaturated compound?
A
CnH2n
9
Q
What is an isotope?
A
A number with the same amount of protons, different number of neutrons
10
Q
What is the formula of alkanes?
A
CnH2n+2
11
Q
What is the formula of alkenes?
A
CnH2n
12
Q
What is the unsaturated compound?
A
CnH2n
13
Q
What is the saturated compound?
A
CnH2n+2
14
Q
What is the formula of calcium carbonate?
A
CaCO3
15
Q
What is limestone also known as?
A
Calcium carbonate
16
Q
Is calcium carbonate a compound or mixture?
A
It is a compound
17
Q
What does calcium carbonate break down into through thermal decomposition?
A
Calcium oxide and carbon dioxide
18
Q
What is heated in a kiln to make cement?
A
Clay and limestone
19
Q
What is used to make mortar?
A
Cement, sand and water
20
Q
What happens to limewater when carbon dioxide is present?
A
It turns cloudy
21
Q
Calcium oxide reacts with water to create what?
A
Calcium hydroxide
22
Q
How do you break down limestone?
A
Thermal decomposition
23
Q
What colour is calcium oxide when it is hot?
A
Yellow
24
Q
What colour is calcium oxide when cold?
A
White
25
How do you produce calcium oxide from calcium carbonate?
Thermal decomposition
26
What is the formula for calcium oxide with water?
CaO + H2O -> Ca(OH)2
27
What is a benefit of limestone quarrying?
Local employment
28
What is produced when Limestone is thermally decomposed?
Calcium oxide and carbon dioxide
29
Why is it difficult to thermally decompose elements in group 1 in class?
Bunsen burners cannot reach a high enough temperature
30
What is mixed with limestone and sodium carbonate to create glass?
Sand
31
Which two ways can calcium carbonate be reacted?
Calcium carbonate and with acids
32
What type of rock is limestone?
Sedimentary
33
How does limewater convert into limestone?
Carbon dioxide is bubbled through it
34
What compound dissolves in water to form limewater?
Calcium hydroxide
35
Carbonates react with acids to create what?
Carbon dioxide
36
What can calcium hydroxide be used for?
Neutralising acidic fields
37
How is concrete made?
Sand and aggregate
38
What are the negatives of limestone quarrying?
- Make the landscape ugly
- Processes cause loud noises
- Destroys habitats
- Transport causes pollution
39
What is a negative of cement factories?
They create lots of dust
40
How is limestone used in a power station chimney?
It neutralises the sulfur dioxide
41
Which is more reactive, sodium or potassium?
Potassium
42
What are the trends as you go down group 1?
- More reactive
- Lower melting point
- Lower boiling point
43
What are the characteristics of transition metals?
They are good conductors of heat and electricity
44
What is an ore?
A rock that contains enough metal to make it economic to extract the metal
45
How are more reactive metals extracted?
Electrolysis
46
How are less reactive metals extracted?
Reduction with carbon
47
How is copper purified?
Electrolysis
48
Why is copper useful for wiring?
It's soft so easily bent and a good conductor of electricity
49
What makes copper useful for plumbing?
Its a good conductor of heat and doesn't react with water
50
What is an alloy?
A mixture of two elements, usually metals
51
Why are alloys harder than pure metals?
They contain atoms of different sizes, which distort the regular arrangements of atoms, making it more difficult for layers to slide over one another
52
What do all alkali metals have in common?
They need to be stored in oil and handled with forceps
53
What determines whether an ore can be extracted by reduction?
Metals lower than carbon in the reactivity series must be extracted by reduction
54
What happens when an ore is reduced?
Oxygen is removed from it
55
What is a negative of electrolysis compared to reduction?
It is much more expensive as it uses more energy
56
What is usually the electrolyte in electrolysis?
A metal salt solution made from the ore e.g copper sulfate
57
Explain how copper is purified?
- Electrons are pulled off copper atoms at the anode, causing them to go into the solution as Cu2+ ions
- Cu2+ ions near the cathode gain electrons and turn back into copper atoms
- The impurities at the anode drop as sludge, whilst pure copper atoms bond to the cathode
58
Why is electrolysis used in the extraction of copper?
Smelting only gives an impure copper atom
59
How is copper extracted from a solution?
Displacement using a more reactive metal
60
What are the new methods of extracting copper ores?
Bioleaching and phytomining
61
What is bioleaching?
Bacteria are used to separate copper from copper sulfide. The solution produces from this process contains copper
62
What is the disadvantage of the new methods of extracting copper?
They are slower and produce less copper
63
Why is it important to recycle metals?
- They are finite
- Extracting new metals causes pollution
- Saves money due to using less energy
64
When is aluminium most useful?
As an alloy
65
What are properties of aluminium and titanium?
Corrosion resistant and low density
66
Why would aluminium be good for building an aeroplane?
Strong, malleable and light
67
What is a use of titanium?
As a hip replacement
68
What are some downfalls of metals?
- Some corrode when exposed to water and air
- If they corrode, they lose strength
- Metal fatigue
69
Which types of steel are made from iron?
- Low carbon steel (0.1% carbon)
- High carbon steel (1.5% carbon)
- Stainless steel (chromium added)
70
Why is crude oil called a fossil fuel?
Because it is formed from the remains of ancient sea creatures
71
Compared to large hydrocarbons, small hydrocarbons are...
More volatile
72
Is the top of an oil fractioning column warmer or colder than the bottom?
Colder
73
What happens to a liquid during its separation from a mixture by distillation?
Evaporation followed by condensation
74
Which fraction has the largest carbon chain?
Bitumen
75
What is a use of kerosene?
Aeroplane fuel
76
How do geologists find oil?
They study the rock structures
77
Which hydrocarbons are less efficient?
Those that have a longer chain
78
What is cracking?
When long hydrocarbon chains are converted into smaller hydrocarbon chains
79
What is a use of bitumen?
Tarmac
80
What is crude oil made up of?
Mostly alkanes
81
If a hydrocarbon molecule chain is shorter?
- It is less viscous
- It is more volatile
- It is more flammable
82
What does volatile mean?
More volatile means it turns into a gas at a lower temperature
83
What are the negative gases produced by fossil fuels?
Sulfur dioxide and carbon dioxide
84
What happens if partial combustion takes place?
Carbon monoxide and soot is released
85
How are sulfur dioxide emissions reduced?
The sulfur is removed before the fuel is burnt, or they are removed after combustion in power station by Aid Gas Scrubbers
86
What causes global dimming?
The soot that is released when fossil fuels are burnt
87
What is the result of global dimming?
Sunlight is reflected back into space
88
What are the alternate fuels being developed?
Ethanol, biodiesel and hydrogen gas
89
What are the positives of using hydrogen gas as a fuel?
It does not emit any harmful emissions
90
What are advantages of ethanol and biodiesel as fuels?
They are carbon neutral carbon neutral
91
What are negatives of ethanol as a fuel?
Engines need to be converted and it isn't widely available
92
What are negatives of biodiesel?
It is expansive and we cant make enough to completely replace diesel
93
What does cryolite do in electrolysis?
Lowers the melting point so less energy needs to be used
94
What were the reasons for continental drift?
- Fossils in the wrong climate
- Matching fossils in different continents
- Jigsaw theory
95
Why didn't some scientist accept Wegener's theory?
- He was an astronomer
- He made incorrect calculations
- Insufficient evidence
96
What causes heat within the mantle?
Radioactive decay
97
What are the proportions of gases in the atmosphere?
80% Nitrogen
20% Oxygen
Small proportions of CO2, water vapour and noble gases
98
What was the earth like during its first 1 billion years?
Intense volcanic activity that released gases that formed the atmosphere and water vapour that cooled to become oceans
99
Which planets was the earths early atmosphere similar to?
Venus and Mars
100
What is the theory as to how life was formed?
There was an interaction between hydrocarbons, ammonia and lightning. There are also many others.
101
What is the primordial soup theory?
Billions of years ago, the atmosphere was made up of nitrogen, hydrogen, ammonia and methane. Lightning struck, causing a chemical reaction, resulting in amino acids. The amino acids became a body of water out of which life eventually crawled (primordial soup).
102
Which gases are involved in the primordial soup theory?
Nitrogen
Hydrogen
Ammonia
Methane
103
What was the Miller - Urey experiment?
A closed experiment which tested the primordial soup theory
104
What were the results of the Miller - Urey experiment?
They found similar results but not exactly the same, leading to questions about the theory
105
Where did most of the carbon dioxide go from the atmosphere?
- Locked up in sedimentary rocks as fossil fuels
| - Dissolved into the ocean
106
What is a negative of the ocean absorbing much of the atmospheres CO2?
It has had an impact on the marine environment
107
What is air?
A mixture of gases with different boiling points
108
Why is air fractionally distilled?
To provide a source of raw materials used in a variety of industrial processes
109
What is the structure in which fractional distillation occurs?
A fractionating column
110
What are the products of cracking?
Alkanes and alkenes
111
What is cracking?
The process which breaks down long-chain hydrocarbons into shorter, more useful hydrocarbons
112
What is the catalyst present when reacting ethene with steam to create ethanol?
Phosphoric acid
113
During ferementation, sugar is converted into what?
Ethanol and carbon dioxide
114
What is polymerisation?
When many monomer join together to form polymers
115
Plastics are an example of what type of polymers?
Synthetic polymers
116
What is added to a plastic bag to make it biodegradable?
Cornstarch
117
Are polymers saturated with single bonds or unsaturated with double bonds?
Saturated with single bonds
118
What does biodegradeable mean?
They are not broken down by micro organisms
119
What are many polymers made from?
Fossil fuels
120
What is the molecular formula for ethanol?
C2H5OH
121
Why is ethanol not a hydrocarbon?
Because it contains oxygen as well as hydrogen and carbon
122
Which two ways can you make ethanol?
Fermentation of a sugar solution and hydration
123
What is a continuous process?
Reactants are constantly being put into the reaction vessel, and products are always being taken out
124
What is a batch process?
The reaction vessel must be emptied and cleaned when the reaction is complete
125
What is the name of the process when seeds are crushed and then the crushed material is squeezed to form oil?
Pressing
126
How can oil that has been extracted by distillation be refined?
By removing water and other impurities
127
Where do biodiesels come from?
Plants which have had their oil extracted
128
Why do chemists crack oil?
To get the more useful materials out of the oil
129
What type of reaction is cracking?
Thermal decomposition
130
Do alkanes or alkenes have a C=C double bond?
Alkenes
131
Describe cracking?
- Heat and vaporise the long chain hydrocarbon
- Pass vapour over a powdered catalyst between 400-700 degrees celcius
- Aluminium oxide is the catalyst used
- The long chain molecules then split on the surface of the catalyst
132
What are the 3 methods for extracting plant oils?
Cold pressing
- Steam distillation
- Solvent extraction
133
What is the highest temperature oils can be extracted using cold pressing?
50 degrees celcius
134
What are advantages of steam distillation?
- Efficient
| - Due to the use of water, a byproduct can be created to sell
135
What physical state is saturated fat at room temperature?
Solid, it also has only C-C single bonds
136
What physical state is unsaturated fat at room temperature?
Liquid, it has double bonds C=C
137
What conditions are needed for hardening oil?
60 degrees, hydrogen and a nickel catalyst
138
How does hydrogenation harden vegetable oil?
The C=C in unsaturated oil breaks open and joins with the hydrogen, to give only C-C bonds and forms unsaturated oil
139
Why is oil better at cooking some foods than using water?
It has a higher boiling point, so the food can be cooked at a higher temperature and will cook quicker
140
Why do unsaturated fats have a lower boiling point?
They have C=C bonds, which means that they cannot rotate as easily, and have smaller intermolecular forces which means they need less energy to change state
141
What is an emulsion?
A mixture of small globules of one liquid suspended in another that are immiscible because they will not mix
142
Why do you use detergent to wash dishes?
It is an emulsifier that allows the emulsion of fat molecules and water molecules to mix up and wash them off the plate
143
What does immiscible mean?
Does not mix or combine
144
What are hydrogenated vegetable oils used for?
Baking and cooking
145
What are the features of an emulsifier?
- Small hydrophilic head
| - Long hydrophobic tail
146
How many different elements are there?
About 100
147
Why is helium different from other noble gases?
It still has a full outer shell, but only has 2 electrons in this shell
148
Why is the mass of products always equal to the mass of reactants?
No atoms are lost or made during a chemical reaction
149
What is formed when a carbonate reacts with an acid?
Carbon dioxide, salt and water
150
How can copper be extracted from copper-rich ores?
Smelting in a furnace
151
What is a blast furnace made up of?
96% iron
152
Why is iron used in a blast furnace?
It stays strong during compression
153
How are oxides of nitrogen formed?
At high temperatures
154
How do alkenes react with bromine water?
Turn it from orange to colourless
155
How do alkanes react with bromine water?
Stays orange (no reaction)
156
What are the new uses for polymers?
- Hydrogels
- Waterproof coatings
- dental polymers
157
What is equation to show the fermentation of sugar?
Sugar -> CO2 + Ethanol
158
Why are vegetable oils very important?
- They provide a lot of energy
| - They provide nutrients
159
What is the main reason that vegetable oils are used?
-Increases the energy that the food releases when it is eaten
160
What is the viscosity of an emulsion?
Thicker than oil
161
How can ethanol be produced?
Hydration of ethene with steam in the presence of a catalyst
| Fermentation with yeast
162
Why are vegetable oils important fuels?
They provide lots of energy
163
Why are vegetable oils important foods?
They provide lots of energy and nutrients
164
Are vegetable oils saturated or unsaturated?
Unsaturated
165
What catalyst is used to harden vegetable oils?
Nickel
166
What conditions are needed to harden vegetable oils?
60°c
167
Why can't aluminium and titanium be extractes from their oxides with carbon?
It's too expensive
168
Why is too expensive to extract aluminium and titanium?
There are too many stages in the process and large amounts of energy are needed
169
Why do most metals to require chemical reactions to extract them?
Because they are mostly found in compounds
170
What is a leachate?
The solution that is produced by the process of bioleaching
| It contains copper
171
What is the process called when copper ore is heated in a furnace?
Smelting
172
What is phytomining?
Growing plants in copper rich soils
173
Why does copper build up in the leaves of plants?
Because it doesn't use or get of the metal
174
What happens after plants are harvested in phytomining?
They are burnt in a furnace and then the copper is collected from the ash
175
How is CO2 removed from the atmosphere?
- Plants photosynthesizing
- Dissolved in oceans
- Locked up in sedimentary rock
176
How is CO2 added to the atmosphere?
- Plants and animals dying
- Fossil fuels burning
- Living things respiring
177
What is the composition of the mantle?
Solid but able to move slowly
178
What produced the oxygen that is now in the atmosphere?
Plants and algae by photosynthesis
179
How was limestone formed?
From the shells and skeletons of marine organisms
180
What is an industrial use of air?
It can be fractionally distilled to provide a source of raw materials
181
What happened when the earth cooled?
Water vapour in the air condensed into oceans
182
What is the emulsifiers effect on food?
- Improve texture
- Improve taste
- Encourages us to eat more high fat foods
183
Which type of fat is better for the health?
Unsaturated
184
How do emulsifiers keep liquids mixed?
The hydrophobic parts of the emulsifier go into small oil droplets, so each droplet is surrounded by the hydrophillic (water)parts. This keeps each oil droplet apart and the mixture together.
185
What are two advantages of cooking with vegetable oil?
- Quicker coooking
| - Releases more energy when food is eaten
186
What are the advantages of hydrogenated oils being solid at room temperature?
They can be used as spreads and to make pastries which require solid fats
187
What is hydration?
The reaction of ethene with steam at a high temperature in the presence of phosphoric acid to create ethanol
188
What are the advantages of using fermentation to create ethanol?
- It is a renewable resource
| - It is done at room temperature
189
What are the disadvantages of using fermentation to create ethanol?
- It produces an impure solution of ethanol
| - It is a long process as it has to be done in batches
190
What are the advantages of using hydration to create ethanol?
- Produces pure ethanol
| - It is a continuous process
191
What are the disadvantages of using hydration to create ethanol?
- It is non renewable
| - Requires a high amount of energy
192
How is ethanol produced by fermentation?
The enzymes in yeast cause plant sugar to convert into ethanoland carbon dioxide
193
What is the formula of ethanol?
C2H5OH
194
What is a smart polymer?
A polymer which changes in response to changes in the environment
195
What is a biofuels?
A fuel made from animal or plant products
196
What is produced when fuels are burned in extreme conditions?
Nitrogen oxides
197
How is iron made from iron oxide?
It is reduced in a blast furnace
198
What does the boiling point of a hydrocarbon depend on?
The size of its molecule - The larger the molecule, the higher the boiling point
199
How do group 1 metals react with water and air?
They all react vigorously with both
200
Which is the only noble gas without 8 electrons in its outer shell?
Helium - it only has 2 electrons in its 1 shell
201
What is limestone needed for?
Building
202
What are the uses of blast furnace iron?
Used as cast iron because of its strength in compression
203
What are the products of complete combustion of hydrogen?
- Water
| - CO2
204
What are the products of incomplete combustion of hydrogen?
- Water
| - Carbon monoxide
205
Copper sulfate + iron -> ?
Iron sulfate + copper
206
Why does iron straight from a blast furnace make it have limited uses?
The impurities make it brittle
207
Why are alloys harder than pure metals?
The mixed size of atoms make the layers harder to slide over eachother
208
Pro's of using ethanol as a fuel?
It produces very little pollution
| A renewable resource
209
Con's of using ethanol as a fuel?
Engines need to be converted before they will work with ethanol fuels
It isn't widely available
210
Why are there worries about an increase demand for ethanol fuel?
Farmers will switch to growing crops for ethanol rather than food crops which will increase food prices
211
Pro's of using hydrogen gas a fuel?
It is clean and renewable
212
How is hydrogen extracted?
Electrolysis of water
213
Con's of using hydrogen gas as a fuel?
You need an expensive engine to be able to run on it
| It is hard to store
214
What are three environmental impacts of burning hydrocarbons?
Encouraging global warming
Acid rain from sulfur dioxide release
Global dimming as soot and ash reflect sunlight back into space
215
What are benefits of using biodiesel?
Its carbon neutral
Engines don't need to be converted
Produces less sulfur dioxide
216
What are some drawbacks/risks of using biodiesel?
We can't make enough to completely replace diesel
| It can improve food prices (same reason as ethanol)
217
What happens to carbon and hydrogen when they are combusted?
They are oxidised
218
What are the two different methods of cracking?
Passing vaporised hydrocarbon over a hot catalyst
| Mix the vaporised hydrocarbon with steam at a very high temperature
219
What is the catalyst used in cracking?
Aluminium oxide
220
What is the catalyst used for hydration of ethene to get ethanol?
HEATED phosphoric acid
221
What are the advantages of using emulsifiers?
They give food a longer shelf life
| They allow food companies to produce food that is lower in fat but still has good texture
222
What is a disadvantage of using emulsifiers in food?
People can be allergic to them, like egg yolks which are commonly used
