Paper 2 Flashcards
(155 cards)
1
Q
Rate =
A
Change in quantity / time
2
Q
Cross practical
A
- react hydrochloric acid and sodium thiosulphate in a conical flask sitting on some paper with a cross
- product formed will turn solution cloudy- it’ll increase the turbidity
- stop timer when you can no longer see the cross
- repeat for a range of different temperatures
3
Q
How can rate of reaction be measured?
A
Measure volume of gas produced by attaching a gas syringe to reaction vessel
4
Q
What does the rate of reaction graph look like
A
Time on x, quantity on y
Steep then levels out, showing reaction has finished
5
Q
How can rate of reaction be INCREASED
A
- increase surface area
- increase pressure
- increase concentration
— all because particles collide more frequently - increase temperature
— particles move faster, so collide more frequently with sufficient energy - add a catalyst
— reduces activation energy, provides an alternative reaction pathway
6
Q
Equilibrium
A
Both forward and backwards reactions happen at the same rate, and the concentrations stay the same
7
Q
How does an increase in pressure or concentration effect equilibrium?
A
Reaction favours the side with the fewest molecules
8
Q
How does removing a product from one side effect rate of equilibrium?
A
Reaction shifts towards the one lost (ie removing ammonia results in more ammonia being made)
9
Q
How does an increase temperature effect equilibrium
A
Favours the endothermic side
10
Q
How does an decrease temperature effect equilibrium
A
Favours the exothermic side
11
Q
Le chateliers principal
A
If a system at equilibrium is subject to a change, the system will work to counteract the change
12
Q
How is crude oil made and what does it consist of
A
- plankton buried underwater and compressed for a long time
- hydrocarbons
13
Q
Describe alkanes
A
CnH2n+2
Saturated- consists of only single covalent bonded carbon atoms surrounded by hydrogen atoms
14
Q
How does fractional distillation work
A
- hydrocarbons are evaporated and rise up the fractionating column where they recondense at different heights
- longer alkanes have higher boiling points so recondense lower
15
Q
As you go up the fractionating column, what happens to temperature?
A
It gets colderb
16
Q
What is produced at each fraction? (Shortest to longest alkane chains)
A
LPG, petrol, kerosene, diesel oil, heavy fuel oil, bitumen
17
Q
What is produced from complete combustion?
A
Carbon dioxide and water
18
Q
Products of incomplete combustion
A
Carbon monoxide/ carbon and water
19
Q
Do longer/shorter alkanes have a higher viscosity?
A
Longer
20
Q
Are longer/shorter alkanes more flammable
A
Shorterb
21
Q
What can hydrocarbons be used to make?
A
Solvents, lubricants, detergents, polymers
22
Q
What can polymers be made from
A
Alkenes
23
Q
Describe alkenes
A
Unsaturated- have at least 1 double bond
CnH2n
24
Q
Test for alkenes
A
Turns bromine water orange- colourless
25
Water can react with an alkene to make
An alcohol
26
When bromine reacts with an alkene, what's broken?
Double bond
27
The demand for __ alkanes is higher than that for ___
Shorter, longer
28
What is cracking used for
To break longer alkanes into a shorter alkane and an alkene
29
Conditions for steam cracking
No catalyst, temperature higher than 800°C
30
Conditions for catalytic cracking
Zeolite catalyst
550°C
31
Functional group for alcohol
OH
32
Functional group for carboxylic acid
COOH
33
Ethanol + sodium --
Sodium ethoxide + hydrogen
34
Alcohols can produce a solution with water, but that's a problem with this?
It gets harder as alcohols get longer
35
An alcohol can be oxidised to form what?
A carboxylic acid
36
Polymers
Long chained organic molecules of repeating sequences, made from monomers
37
How does addition polymerisation work?
Monomers joined together must contain a double bond, which is then broken in order to produce a single bond which then bonds to the next monomer
38
What does ethene become by addition polymerisation?
Polyethene
39
Condensation polymerisation
Polymerisation of different monomers that have different functional groups on the ends
40
Reacting an alcohol and carboxylic acid does what?
Makes a polyester and small molecule (water)
41
Amino functional group
NH2
42
What do amino acids contain
An amino group and a carboxyl group
43
Amino acids can be polymerised to make
Polypeptides and proteins
44
What's DNA stand for?
Deoxyribonucleic acid
45
What are the monomers called that make up the polymer strands in DNA?
Nucleotides
46
Starch is a polymer of
Glucose
47
Starch is a polymer of
Beta- glucose
48
How can you identify pure substances?
They have very specific melting/boiling points
49
Formulations
Mixtures of certain quantities of substances designed to fulfill a specific purpose
50
Examples of formulations
Paints
Fuels
Alloys
Fertilisers
51
Chromatography
Separating a mixture to identify whether its pure or not, and what it's made of
52
Mobile phase
Solvent - pulls substances in the mixture upwards with lighter particles being moved further up
53
Stationary phase
Chromatography paper or filter paper
54
Why do we draw the line with a pencil in chromatography?
It won't separate or travel up the paper
55
Rf value
Distance travelled by substance // distance travelled by solvent
56
How many spots will a pure substance produce
1
57
How many spots will an impure substance produce
2 or more
58
Test for hydrogen
Lit splint produces a squeaky pop
59
Test for oxygen
Glowing splint relights
60
Test for carbon dioxide
Limewater turns clear - cloudy when gas is bubbled through it
61
Test for chlorine
Bleaches blue litmus paper white
62
Flame test for lithium
Crimson
63
Flame test for sodium
Yellow
64
Flame test for potassium
Lilac
65
Flame test for calcium
Orange - red
66
Flame test for copper
Green
67
Format of ionic equation in testing for metals
Metal + hydroxide -- metal hydroxide
Cu2+ + 2OH- --- Cu(OH)2
68
Test for metal using sodium hydroxide: aluminium
White precipitate, dissolves with excess NaOH
69
Test for metal using sodium hydroxide: calcium
White precipitate, dissolves with excess NaOH
70
Test for metal using sodium hydroxide: magnesium
White precipitate, dissolves with excess NaOH
71
Test for metal using sodium hydroxide: copper (II)
Blue precipitate
72
Test for metal using sodium hydroxide: iron (II)
Green precipitate
73
Test for metal using sodium hydroxide: iron (III)
Brown precipitate
74
Haber process (the actual process)
- nitrogen and hydrogen are pumped through pipes
- the pressure of the mixture of gases is increased to 200
atmospheres
- the pressurised gases are heated to 450°C and passed through a tank containing an iron catalyst
- the reaction mixture is cooled so that ammonia liquefies and can be removed
- unreacted nitrogen and hydrogen are recycled
75
Carbonates react with acid to produce
Carbon dioxide
76
Halide ions will produce a precipitate when mixed with what
Silver nitrate and nitric acid
77
When mixed with silver nitrate and nitric acid, what colour do chloride ions turn?
White
78
When mixed with silver nitrate and nitric acid, what colour do bromide ions turn?
Cream
79
When mixed with silver nitrate and nitric acid, what colour do iodide ions turn?
Yellow
80
Sulphate ions produce a white precipitate when mixed with what
Barium chloride and hydrochloric acids
81
What are sophisticated instruments like and what can they do?
- accurate, sensitive, rapid
- they can analyse substances effectively
82
What is flame emission spectroscopy?
Analysing wavelengths of light emitted from a flame; which can accurately identify ions
83
Greenhouse gases
Water vapour, methane, carbon dioxide
84
Global warming
A rise in global temperatures
85
Carbon footprint
Measure of how much CO2 is released into the atmosphere over an organisms life
86
How is carbon monoxide damaging to organisms?
Binds to haemoglobin in red blood cells, reducing oxygen they transport around the body
It's odourless and colourless
87
How does sulfur dioxide harm organisms
Causes acid rain, which corrodes metals and erodes stone
88
How is nitrogen oxide harmful to organisms
Respiratory problems
89
How is soot/carbon particles harmful to organisms?
Causes health issues
90
What are resources needed for?
Warmth
Shelter
Food
Transport
91
What are examples of resources?
Food
Wood
Fuel
Materials
92
We supplement resources through agriculture, but are trying to replace them with...
Synthetic materials
93
Sustainability
Using natural materials that fulfill our needs, but in a way that future generations can also fulfill theirs
94
Potable water
Water that is drinkable as it has low levels of dissolved salts and microbes
95
How is potable water produced?
- obtained from freshwater source
- passed through a filter bed to remove large insoluble particles
- sterilised to kill microbes using chlorine, ozone or UV
96
Desalination
Removal of salt from seawater by distillation or reverse osmosis- both of which require lots of energy
97
Where does waste water come from?
Toilets
Industrial processes
98
What must be removed before waste water is released back into the environment?
Harmful chemicals
99
Describe the process of treating waste water
- screened and grit is removed
- sedimentation
- liquid effluent treated aerobically and sludge treated anaerobically
100
How are most metals obtained?
By their ore, which is mined from the ground
101
How are pure metals obtained?
By electrolysis or displacement reaction from the ore
102
Phytomining
Plants absorb copper ions into their roots so the plants are burned and copper is obtained from ash
103
Bioleaching
Bacteria produce leachate solutions containing copper ions that can be extracted
104
Disadvantage of phytomining and bioleaching?
Very low yields
105
Why is a life cycle assessment carried out?
To predict impact of a new product in the environment
106
What is considered as part of the LCA?
- extraction of raw materials
- manufacturing/ packaging
- use over its lifetime
- disposal
- transportation
107
How can we reduce our impact?
- using products less
- reducing materials and energy needed to make things
- recycling
108
Corrosion
Destruction of metals over time due to chemical reactions
109
Iron and steel rusts when it corrodes due to
Reactions with oxygen AND water
110
Copper corrodes when
It reacts with oxygen, making green copper oxide
111
Sacrificial protection
Covering metals with other materials that will corrode before metals underneath- these can then be replaced
112
Galvanising
Covering another metal with zinc in order to prevent rust
113
What's bronze an alloy of?
Copper and tin
114
What's brass an alloy of?
Copper and zinc
115
What's gold jewellery an alloy of?
Gold, silver, copper, zinc
116
What's steel an alloy of?
Iron and carbon
117
What's stainless steel an alloy of?
Steel and chromium/ nickel
118
What's aluminium used to make?
Low density/light alloys
119
Why are alloys stronger than pure metals?
Different size atoms disrupting the lattice so layers cannot slide over each other
120
Does soda lime glass or borosilicate glass have the higher melting point?
Borosilicate
121
How is soda lime glass made?
Heating sand, sodium carbonate and limestone
122
How is borosilicate glass made?
Heating sand and boron trioxide
123
How is pottery made?
Heating shaped clay in a furnace
124
Composites
Combination of 2 materials with one binding to the other, making strong, light materialsb
125
HDPE
High density polyethene
126
LDPE
Low density polyethene
127
Thermosoftening polymers ___ when heated
Melt
128
Thermosetting polymers ___ when heated
Don't melt, because of cross links between polymers, which increase attractive forces between layers
129
What is the equation for the haber process?
N2 + 3H2<--> 2NH3
130
Where does nitrogen for the haber process come from?
Air
131
Where does hydrogen for the haber process come from?
Natural gases
132
Why is a compromise temperature used in the haber process?
High temp increases rate of reaction, but also favours the backwards reaction, making less ammonia
133
Why is a compromise temperature important?
It maximises yield of ammonia produced while also ensuring reaction happens at a reasonable rate
134
What are NPK fertilisers made from?
Nitrogen
Phosphorus
Potassium
135
Ammonia is used to make
Ammonium salts
136
Potassium chloride and potassium sulphate are obtained by
Mining
137
Phosphate rock is mined then ___ before it's added to fertiliser
Treated with acid
138
How is fresh water treated?
1. Filter out debris, let large dirt settle to bottom
2. Sterilise with chlorine, ozone of UV
139
How is salt water treated?
1. Filter out large objects
2. Desalinate by high temperature distillation or high pressure reverse osmosis
140
How is sewage water treated?
1. Filter out debris
2. Sedimentation produces liquid effluent and solid sludge which sinks
3. Sludge treated anaerobically and effluent treated aerobically
141
Ammonia + nitric acid
Ammonium nitrate
142
Ammonia + sulfuric acid
Ammonium sulfate
143
Ammonia + phosphoric acid
Ammonium phosphate
144
Phosphate rock + nitric acid, and then ammonia
Ammonium phosphate
145
Phosphate rock + sulfuric acid
Calcium phosphate + calcium sulfate
146
Phosphate rock + phosphoric acid
Calcium phosphate
147
HDPE
Formed at lower pressure with a catalyst
Polymer chains are regular lines that pack closely together
Stronger heavier polymer formed
Used in pipes, plastic plates
148
LDPE
Made at high pressure
Polymer chains form fast and randomly creating lots of side branches
Prevents individual poly chains packing closely together
Used for carrier bags
149
Combustion of alcoholsb
- burn cleanly
- burn with a clear blue flame and little smoke
150
How are alcohols formed
Fermentation of sugar
Needs yeast
35-40°
151
Functional group of esters
COO
152
How did oxygen in the atmosphere increase?
- photosynthetic bacteria photosynthesised using carbon dioxide and water
- algae evolved into plants which, as they got bigger, photosynthesised more, producing more oxygen
153
How did carbon dioxide decrease in thr atmosphere?
- dissolved in oceans
- used by plants to grow stems, leaves etc
- used by animals to make shells and bones
154
How dis nitrogen increase in the atmosphere?
- produced in small amounts by volcanoes
- volcanoes produced ammonia which reacted with oxygen to form nitrogen and water
- unreactive so accumulated in atmosphere over many years
155
How greenhouse effect works:
1. Short wave UV energy comes from sun
2. Some is reflected
3. Some is absorbed on earth's surface, loses a bit of energy and is re-emitted as longwave IR, and some IR radiation hits a greenhouse gas
4. Greenhouse gases absorb energy from longwave radiation
5. This heats up the earth
