Rouge et Orange Flashcards
(89 cards)
1
Q
How is an addition polymer formed?
A
By joining up many small molecules (monomers) which have C=C bonds (alkenes)
- using an initiator and high pressure, many monomers open their double bonds and polymerise to form very long saturated chains (polymers)
2
Q
What are the uses of poly(ethene) and why? (3)
A
- light, stretchable polymer
- plastic bags, bottles, containers
3
Q
What are the uses of poly(propene) and why? (3)
A
- very tough polymer but flexible and resistant to heat
- kettles, food containers, carpets
4
Q
What are the uses of poly(chloroethene)? (3)
A
- clothing
- pipes
- insulating electrical cables
5
Q
Why are addition polymers hard to dispose of? (2)
A
- inert ( don’t react easily) because C-C bonds in polymer chain are very strong so not easily broken
- so takes a long time to biodegrade
6
Q
What does the haber process manufacture?
A
Ammonia (NH3)
7
Q
In the haber process, where is the nitrogen obtained from?
A
Air
8
Q
In the haber process, where is the hydrogen obtained from?
A
Natural gas or the cracking of hydrocarbons
9
Q
What are the conditions for the Haber process? (3)
A
Pressure: 200 atm
Temperature: 450 °C
Catalyst: Iron
10
Q
What is the equation used in the haber process?
A
N2 + 3H2 ⇌ 2NH3 (+ heat)
11
Q
What happens to the ammonia released and the unused hydrogen and nitrogen after the haber process has taken place?
A
- The ammonia is formed as a gas, but cools in the condenser, liquefies, and is then removed
- the unused H2 and N2 are reycled and recirculated
12
Q
In the haber process, what is the ammonia produced used for?
A
- to make nitric acid (HNO3)
- to make fertilisers by reacting ammonia with nitric acid to get ammonium nitrate
13
Q
Why is ammonium nitrate a good fertiliser?
A
- has nitrogen from two sources, the ammonia and the nitric acid. Plants need nitrogen to make proteins
14
Q
What are the conditions for cracking in industry? (2)
A
Temperature: 600-700°C
Catalyst: Silica (SiO2) or Alumina (Al2O3)
15
Q
What is the issue of supply and demand in fractional distillation which makes cracking necessary?
A
- fractional distillation of crude oil produces more long chain hydrocarbons than can be used directly and fewer short chain hydrocarbons than are required as short chain hydrocarbons can be used as fuels
- to meet this demand, cracking is necessary to split long chain hydrocarbons into short chain molecules
16
Q
Cracking is a form of … decomposition
A
Cracking is a form of THERMAL decomposition
17
Q
Cracking is the process of…
A
splitting long chain hydrocarbons into more useful short chain molecules and alkenes which can be used to make polymers
18
Q
What does homologous series mean?
A
a group of compounds that can all be represented by the same general formula
19
Q
What does hydrocarbon mean?
A
molecules which are made up of hydrogen and carbon atoms only
20
Q
What does saturated mean?
A
- a chemical compound that has a chain of C-C bonds. All bonds are already formed.
- alkanes are saturated hydrocarbons.
21
Q
What does unsaturated mean?
A
- a chemical compound that has a chain of C=C bonds. The double bond can open up and they can make more bonds.
- alkenes are saturated hydrocarbons.
22
Q
What is an isomer?
A
Isomers are molecules that have the same molecular formula, but have a different structure.
SAME MOLECULAR FORMULA
DIFFERENT STRUCTURE
23
Q
What is the general formula of alkenes?
A
CnH2n
24
Q
What is the general formula of alkanes?
A
CnH2n+2
25
What is the formula of methane?
CH4
26
What is the formula of ethane?
C2H6
27
What is the formula of propane?
C3H8
28
What is the formula of butane?
C4H10
29
What is the formula of pentane?
C5H12
30
What is the equation for complete combustion of alkanes?
alkane + oxygen -> carbon dioxide + water (+ energy)
31
What is the equation for incomplete combustion of alkanes?
alkane + oxygen -> carbon + carbon monoxide + carbon dioxide + water (+ energy)
32
What is the flame colour in complete combustion?
clean blue
33
What is the flame colour in incomplete combustion?
smokey yellow
34
Describe the reaction between alkanes and halogens and the reaction between methane and bromine as an example
alkane + halogen -> haloalkane
- substitution reaction as a hydrogen atom from the alkane (methane) is replaced by a halogen atom (bromine)
- happens in the presence of UV light
eg. methane + bromine -> bromomethane + hydrogen bromide
35
Halogens only react with alkanes in the presence of....
Ultraviolet light
36
What is the formula of ethene?
C2H4
37
What is the formula of propene?
C3H6
38
What is the formula of butene?
C4H8
39
Describe the reaction between alkenes and halogens and the reaction between ethene and bromine as an example
alkene + halogen -> haloalkane
- addition reaction as the C=C bond is split and a halogen atom added to each of the carbons (hence di)
eg. ethene + bromine -> dibromoethane
- often used as a test for C=C bonds
- when you shake an alkene in orange bromine water, it decolourises because the orange bromine molecules react with the alkene to make a colourless dibromoalkane
40
acids are sources of ..... ions
acids are sources of H+ ions
41
bases are sources of ..... ions
bases are sources of OH- ions
42
Litmus paper is ... in acid
Litmus paper is RED in acid
43
Litmus paper is ... in alkaline
Litmus paper is BLUE in alkaline
44
Phenolphthalein is ... in acid
Phenolphthalein is COLOURLESS in acid
45
Phenolphthalein is ... in alkaline
Phenolphthalein is PINK in alkaline
46
Methyl orange is ... in acid
Methyl orange is RED in acid
47
Methyl orange is ... in alkaline
Methyl orange is YELLOW in alkaline
48
The reaction between an acid and a base is called...
neutralisation
49
acid + base ->
acid + base -> salt + water
50
acid + metal oxide ->
acid + metal oxide -> salt + water
51
acid + metal carbonate ->
acid + metal carbonate -> salt + water + carbon dioxide
52
all sodium, potassium, and ammonium salts are ...
all sodium, potassium, and ammonium salts are SOLUBLE
53
all nitrates are ...
all nitrates are SOLUBLE
54
all chlorides are ... except silver chloride which is ...
all chlorides are SOLUBLE except silver chloride which is INSOLUBLE
55
all sulfates are ... except barium sulfate and calcium sulfate which are ...
all sulfates are SOLUBLE except barium sulfate and calcium sulfate which are INSOLUBLE
56
all carbonates are ... except sodium, potassium, and ammonium carbonates which are ...
all carbonates are INSOLUBLE except sodium, potassium, and ammonium carbonates which are SOLUBLE
57
How do you make a soluble salt using an acid and an insoluble base?
- pick an acid and an insoluble base
- add the insoluble base to the acid, you will know when the acid has been neutralised as the excess solid base will sink to the bottom of the flask
- filter off the excess base to get the salt solution
- evaporate the water to get salt crystals
58
What are some good insoluble bases?
most metal oxides, metal hydroxides, and metal carbonates
59
How do you make a soluble salt using an alkali?
Using a titration!!
- put alkali in conical flask with indicator
- fill burette with acid and add gradually, stirring
- indicator changes colour when alkali has been neutralised
- repeat using same volumes of acid and alkali but without indicator so salt isn't contaminated
60
How do you make an insoluble salt?
- precipitation reaction
- mix two solutions containing soluble salts
- a precipitate will form of the insoluble salt
61
What is ionic bonding?
A strong electrostatic attraction between oppositely charged ions
62
Why do ionic compounds have high melting and boiling points?
because of the strong electrostatic forces of attraction between oppositely charged ions
63
What is covalent bonding?
A strong attraction between the bonding pair of atoms and the nuclei of the atoms involved in the bond
64
Enthalpy change equation.
Enthalpy change (delta h) = total energy absorb to break bonds - total energy released in making bonds
65
Equation used to calculate energy transferred in a reaction.
Energy transferred (j) = mass of water heated (g) x specific heat capacity of water (4.2) x temperature change
66
How to work out moles of gas in a given volume.
No. of moles of gas = volume of gas ART (dm3) / 24
67
What is the main ore of Aluminium?
Bauxite
68
Symbol formula for aluminium oxide?
Al2O3
69
What is aluminium oxide dissolved in to bring down the melting point from 2000°C to 900°C?
molten cryolite (a less common ore of aluminium)
70
Why does molten aluminium conduct electricity?
Because it has ions which are free to move
71
Which electrode are the Al3+ ions attracted to in the extraction of Aluminium?
Cathode (-ve electrode)
72
Which electrode are the O2- ions attracted to in the extraction of Aluminium?
Anode (+ve electrode)
73
What are the two things which can happen to O2- ions at the anode during the extraction of aluminium?
- oxygen ions will react together to form O2
| - oxygen ions will react with the carbon anode to form CO2
74
What is the half equation at the Cathode during the extraction of aluminium?
Al3+ + 3e- -> Al
75
What is the half equation at the Anode during the extraction of aluminium?
2O2- -> O2 + 4e-
76
Why is electrolysis expensive?
- uses a lot of electricity
| - lot of energy is needed to heat the electrolyte mixture to 900°C
77
What is the main ore of iron, which it is extracted from in a blast furnace?
Haematite, Fe2O3
78
What are the raw materials in the extraction of iron in a blast furnace?
- Haematite (iron ore)
- Coke (pure carbon for reducing iron oxide to iron metal)
- Limestone (to remove impurities)
79
What is the temperature inside a blast furnace?
1500°C
80
What is the 1st equation in the blast furnace, where coke reacts with oxygen to produce carbon dioxide?
C + O2 -> CO2
81
What is the 2nd equation in the blast furnace, where carbon dioxide forms carbon monoxide by reacting with excess coke?
CO2 + C -> 2CO
82
What is the 3rd equation in the blast furnace, where iron ore is reduced to iron?
3CO + Fe2O3 -> 2Fe + 3CO2
83
What happens to the iron metal after it has been reduced by carbon monoxide from iron ore?
It is molten and very dense, so runs to the bottom of the furnace and is tapped off.
84
What is the main impurity in the extraction of iron process?
Sand (silicon dioxide) SiO2
85
What removes the impurity silicon dioxide during the extraction of iron?
Limestone
86
What happens to the limestone before it can remove silicon dioxide impurities? (equation)
CaCO3 -> CaO + CO2
Limestone is thermally decomposed by the heat into calcium oxide and carbon dioxide
87
How is slag formed?
By reacting calcium oxide and silicon dioxide (sand) to form calcium silicate (slag).
CaO + SiO2 -> CaSiO3
88
What is the symbol formula for slag?
CaSiO3 (Calcium silicate)
89
What can cooled slag be used for?
- Fertiliser
| - Road building
