Chemistry C1 Flashcards
0
Q
Cathode
A
Negative
Hydrogen only comes out here
1
Q
What is produced by all acids in electrolysis
A
Hydrogen
2
Q
Annode
A
Positive
Oxygen and chlorine only come out here
3
Q
Electrolysis of hydrochloric acid
A
Decomposes into hydrogen and chlorine gas
At the annode, it bubbles and fills slowly with a green gas that bleaches damp blue litmus (chlorine)
At the cathode, it bubbles rapidly with a gas that burns with a squeaky pop (hydrogen)
4
Q
Electrolysis
A
The breaking down of a compound using electricity
Electricity comes from a direct current source
Electricity is applied by 2 electrodes
5
Q
Ores
A
An ore is a rock from which enough metal can be extracted to make a profit
Finite resource
The more reactive the metal is the harder it is to extract
6
Q
Different ways to extract metals
A
Electrolysis- potassium, sodium, aluminium
Heating with carbon- zinc, iron, tin, lead
7
Q
Oxidation
A
A chemical reaction in which an element or compound gains oxygen
8
Q
Reduction
A
A chemical reaction in which an element or compound loses oxygen
9
Q
Redox reaction
A
Where oxidation and reduction is taking place at the same time
10
Q
Oxidising agent
A
Adds oxygen to another substance
11
Q
Reducing agent
A
Takes away oxygen from another substance
12
Q
Rusting of iron
A
Oxygen and water must be present
13
Q
Things that encourage rusting
A
Acid
Copper
14
Q
Slows down rusting
A
Magnesium
15
Q
Alloys
A
Make metals better
Cannot write a formula for them
Mixture of two elements of which one is a metal
16
Q
Smart alloys
A
Change their properties if the conditions change
17
Q
Crude oil
A
- Mixture of hydrocarbons
- Each faction is NOT pure
- It’s a mixture so the different hydrocarbon molecules are not chemically bonded and keep their original properties
18
Q
Lovely Ponies Neigh Proudly Down Fluffy Long Bridges
A
LPG- cooking, camping gas, lighters Petrol- fuel for cars Naphtha- making other chemicals Paraffin (kerosene) -jet fuel Diesel oil- large machines, trains Fuel oil- ships Lube oil- axel greases Bitumen-Tarmac, waterproofing houses, rooves
19
Q
Complete combustion
A
When there is no limit to the amount of oxygen you have
Releases lots of energy and no harmful waste products
Clean blue flame
20
Q
Fuel
A
A substance that releases usable energy
21
Q
Hydrocarbons
A
Substances that contain only carbon and hydrogen joined together
22
Q
Alkanes
A
- Made up of chains of carbon atoms with single bonds
- Saturated because no spare bonds
- Don’t turn bromine colourless (no spare bonds)
- Don’t form polymers
Methane - Ethane - Propane
23
Q
Cracking
A
Splitting up long chain hydrocarbons to form alkenes
Thermal decomposition – uses heat
24
Polymerisation
Turning alkenes into long chains
25
3 phases of Atmosphere evolution
1. Volcanoes gave out gases
2. Green plants evolved and produced oxygen
3. Ozone layer allows evolution of complex animals
26
Volcano gas release
- The earths surface was originally molten, any atmosphere boiled away
- Eventually a thin crust formed
- Volcanoes gave out lots of gas
- Oceans formed
27
Why were oceans formed?
Volcanoes gave out gas such as CO2 and Oxygen which condensed to create the oceans and atmosphere
28
Early atmosphere
Mostly CO2 with virtually no Oxygen
29
Green plants evolved and produced oxygen
1. A lot of the CO2 dissolved into the oceans
2. Marine organisms developed and took in the CO2, they died and were locked in carbonate rocks
3. Green plants evolved taking in the CO2 and using photosynthesis to turn this into oxygen
30
Ozone layer allows evolution of complex animals
1. Build up of oxygen killed of organisms that couldn't take it but more complex organisms began to develop
2. Oxygen created Ozone layer (O3) blocked harmful rays
3. Little CO2
31
Today's atmosphere
Atmosphere is still changing due to human and volcano activity.
Sources of information on the evolution of the atmosphere is limited
32
How is human activity changing the atmosphere?
1. Burning fossil fuels releases CO2
2. Deforestation contributes to rising CO2 less trees converting it
3. Livestock farming releases huge amounts of methane
33
How is volcanic activity changing the atmosphere?
1. Sulphur dioxide can be thrown high into the atmosphere when they erupt, this reacts with sunlight water and oxygen to form smog
2. Carbon dioxide is released by volcanic eruptions
34
Why are information sources on the evolution of the atmosphere limited
- We've learned a lot from Antarctic ice cores. Bubbles of air get trapped in new layers each year
- However this must be precise as the changes are tiny
- Some is down to guesswork because no one was actually around at the time
35
Experiment to investigate the proportion of Oxygen in the atmosphere
1. When heated copper reacts with the oxygen in the air
2. If u heat an excess of copper and pass air over it using 2 syringes. You use the markers to find how much oxygen has been used up starting with 100cm3 of air
36
Chemical equation for oxygen proportion test
2cu + O2 --> 2CuO
37
Three types of rock
Sedimentary
Igneous
Metamorphic
38
Sedimentary
1. Formed from layers of sediment laid down in lakes or seas
2. Layers get pressed squeezing out the water
3. Fluids flowing through pores deposit natural cement
Limestone and chalk
39
Metamorphic
- Formed from other rocks in pressure and heat over time
- Chemical composition= same as original
- Don't actually melt
Marble
40
Marble
Formed from limestone or chalk
Very high temperatures break down limestone and reforms as small crystals
41
Igneous rocks
1. When molten magma pushes up into the crust or through it before cooling and solidifying
2. Various different minerals and randomly arranged interlocking crystals
Granite
42
Two types of igneous rocks
Extrusive
Intrusive
43
Extrusive
Igneous rocks cool quickly above ground
Small crystals
Basalt
44
Intrusive
Igneous rocks call slowly underground
Form big crystals
Granite
45
Limestone uses
```
Building material
Statues
Crushed up for road surfacing
With powdered clay to make cement
Glass
Neutralise acidic soil
```
46
Advantages of limestone
- Many uses
- Neutralise sulphur dioxide
- Quarry provides jobs + brings money to local economy
- Once quarrying is complete restoration is required
47
Limestone disadvantages
- Acid rain erodes it
- Quarrying it makes ugly holes
- Quarrying process makes lots of noise and dust
- Destroys habitats of birds and animals
- Limestone needs to be transported away
- Waste materials produce tips
48
Limestone thermal decomposition
Calcium carbonate --> calcium oxide+ carbon dioxide
CaCO3--> CaO + CO2
Other carbonates decompose the same way
49
Thermal decomposition of carbonates
Zinc carbonate and copper carbonate thermally decompose in the same way as calcium carbonate to form an oxide and carbon dioxide
Less stable carbonates will decompose faster
50
Calcium oxide reaction with water
CaO + H2O --> Ca (OH)2 calcium hydroxide
Can be used to neutralise acidic soil
Dissolves in water to create limewater
51
Atoms aren't lost or made in chemical reactions
They are just arranged in different ways to give new products
The mass is the same
52
Reaction in a sealed container
The total mass doesn't change
Good example is a precipitation reaction
Eg copper sulphate and sodium hydroxide
53
Acid
Substance with a pH less than 7
54
Base
Insoluble alkali
55
Alkali
Substance with a pH greater than 7
56
Neutralisation between acids and bases
Forms salt and water
Products are neutral
Acid + base --> salt + water
57
Salt uses
Fertilisers- ammonium nitrate, ammonium phosphate
Fireworks as colouring agents
58
Stomach produces Hydrochloric acid
1. Helps with digestion- enzymes work best in acidic environment
2. Acid helps to kill bacteria prevents food poisoning
59
Indigestion is caused by
Too much hydrochloric acid in the stomach
Indigestion tablets contain bases such as calcium carbonate which neutralises the excess acid
60
Test how much acid a single tablet can neutralise
Crush up one dose and dissolve in a volume of water
Add three drops of indicator
Fill a burette with hydrochloric acid
When colour stays then stop
Work out volume of HCL it could neutralise
61
Metal oxides and metal hydroxides are often bases
This means they can be neutralised with acids to for, salt and water
62
The combination of mets, and acids decides the salt
Eg hydrochloric acid + copper oxide
----------------->
Copper chloride + water
63
What happens when carbonates neutralise acids
They give off CO2
64
Electrolyte
The solution in electrolysis
65
Test for chlorine
Bleaches damp blue litmus paper
66
Danger of chlorine
Chlorine is toxic
67
Three uses of chlorine
Treat water supplies
Needed for the manufacture of bleach
Used to make the polymer polychloroethene
68
Electrolysis of water
Gives hydrogen and oxygen
69
Test for oxygen
The gas will relight a glowing splint
70
Properties of metals
Strong
Bendy
Conductors
71
Aluminium
low density, corrosion resistant
Window frames, aircraft
72
Why do we make alloys
In order to make pure metals stronger and increase the uses
73
Why are alloys harder?
Different sized atoms so making it harder for atoms to slide over each other therefore the alloy is harder
74
Example of a smart alloy
Nitinol- nickel and titanium
| Can be used for glasses frames
75
Incomplete combustion
When there isn't enough oxygen
Carbon monoxide produced
Carbon produced
NOT SAFE
76
Choosing a good fuel
Ease of ignition
Energy value
Ash and smoke
Storage and transport
77
Environmental problems with burning fossil fuels
- if incomplete then carbon monoxide and Carbon produced
| - Contains sulphur impurities so sulphur dioxide produced which causes acid rain
78
Acid rain
Caused by sulphur dioxide reacting with clouds to produce dilute sulphuric acid
Kills trees and damages buildings
Causes lakes to become acidic
79
Sulphur can be removed from fuels before they're burnt
This takes more energy which takes more fuel which releases more CO2
80
Acid rain prevention
Acid gas scrubbers to take harmful gases out before they're released
Cars have catalytic converters to clean up exhaust gases
Reduce use of fossil fuels
81
Carbon dioxide problems
Greenhouse gas so acts as an insulating layer keeping heat in
Affected by humans- respiration, burning trees, deforestation, fossil fuels
82
Biofuels
Biogas- microorganisms used to compose living organisms waste
Alcohol- eg ethanol made from sugar
However large amounts of land are needed where we could be growing food
83
How fuel cells work
Hydrogen and Oxygen give out energy when they react + it only produces water
Uses a fuel and oxygen to generate electricity
84
Fuel cell
An electrical cell that's supplied with a fuel and oxygen and uses energy from the reaction between them to generate electricity
85
Hydrogen-oxygen fuel cell advantages
More efficient
Directly from reaction (no turbines etc)
Aren't as many stages for heat to be lost
No moving parts so energy isn't lost from friction
No pollutants
86
Hydrogen oxygen fuel cell disadvantages
Gas so takes more space to store than liquid fuels
Very explosive so difficult to store safely
Made using electricity that must be generated
87
Alkenes
- Chains of carbon atoms with double bonds
- Unsaturated
- Decolourise Bromine water by forming bonds with the bromine atoms
- They form polymers by opening their double bonds
Ethene - Propene
88
Cracking advantages
Turns them into shorter more useful molecules
More demand for shorter molecules
Produce alkenes for plastics
89
Conditions for cracking
Heat + catalyst
90
Experiment for cracking
Mineral wool soaked in paraffin
Porcelain chips
Into glass jar
91
Incomplete combustion
When there isn't enough oxygen
Carbon monoxide produced
Carbon produced
NOT SAFE
92
Choosing a good fuel
Ease of ignition
Energy value
Ash and smoke
Storage and transport
93
Environmental problems with burning fossil fuels
- if incomplete then carbon monoxide and Carbon produced
| - Contains sulphur impurities so sulphur dioxide produced which causes acid rain
94
Acid rain
Caused by sulphur dioxide reacting with clouds to produce dilute sulphuric acid
Kills trees and damages buildings
Causes lakes to become acidic
95
Sulphur can be removed from fuels before they're burnt
This takes more energy which takes more fuel which releases more CO2
96
Acid rain prevention
Acid gas scrubbers to take harmful gases out before they're released
Cars have catalytic converters to clean up exhaust gases
Reduce use of fossil fuels
97
Carbon dioxide problems
Greenhouse gas so acts as an insulating layer keeping heat in
Affected by humans- respiration, burning trees, deforestation, fossil fuels
98
Biofuels
Biogas- microorganisms used to compose living organisms waste
Alcohol- eg ethanol made from sugar
However large amounts of land are needed where we could be growing food
99
The reactivity series- electrolysis
```
Purple
Sausages
Crave
Minty
Apples
```
```
Potassium K
Sodium Na
Calcium Ca
Magnesium Mg
Aluminium Al
```
100
The reactivity series- carbon
```
Crazy
Zebras
Illustrate
Tin
Ladders
```
```
Carbon
Zinc
Iron
Tin
Lead
```
101
Acid+ Metal carbonate
Salt + water + CO2
102
Hydrochloric acid + Sodium Carbonate
2HCl + Na2CO3 --> 2NaCl + H20 + CO2
103
Hydrochloric acid + Calcium Carbonate
2HCl + CaCO3 --> CaCl2 + H2O + CO2
104
Copper
hard, strong, good conductor
Electrical wires, pipes
105
Gold
easy to shape, unreactive
Jewellery
