Chemistry Flashcards
(102 cards)
1
Q
What happens to the temp in exothermic?
A
It increases
2
Q
What happens to the temp in endothermic?
A
It decreases
3
Q
What happens to the energy in exothermic?
A
It is transferred from stores of energy in chemical bonds to the surroundings
4
Q
What happens to the energy in endothermic?
A
It is transferred from the surroundings to stores of energy in chemical bonds
5
Q
Bond breaking is…
A
Endothermic
6
Q
Bond making is…
A
Exothermic
7
Q
What does it mean if the energy change is negative?
A
Exothermic
8
Q
What happens if the nervy change is positive?
A
It is endothermic
9
Q
How can you extract nitrogen from the air?
A
Fractional distillation
10
Q
What are the conditions of the harbour process? 
A
Iron catalyst
High temp - 450
High pressure - 200atm
11
Q
What does an increase in temp do to the endothermic process?
A
Favour it
12
Q
What is crude oil?
A
A natural resource
13
Q
What is crude oil made from?
A
Fossilised remains of plants and sea creatures
14
Q
What is crude oil a mixture of?
A
Hydrogens and carbon ONLY!
15
Q
What does crude oil need to happen to become useful?
A
It needs to be separated into different compounds
16
Q
What makes crude oil not great?
A
It is not runny enough so it’s difficult to ignite
17
Q
How do you separate crude oil?
A
Fractional distillation
18
Q
What are gases used for?
A
Domestic heating and cooking
19
Q
What is pertrol used for?
A
Fuel in cars
20
Q
What is kerosene used for?
A
Fuel for aircraft’s
21
Q
What is diesel oil used for?
A
Fuel for some cars and trains
22
Q
What is fuel oil used for?
A
Fuel for large ships and power stations
23
Q
What it bitumen used for?
A
Surfacing roads and roofs
24
Q
What does the chain length do to fuels?
A
The shorter carbon chains the weaker the intermolecular forces are between carbon chains
25
What does the boiling point do in chain length?
Increase
26
Why does the boiling point with chain length increase? 
Stronger inter molecular forces between the chains of molecules, so it needs more energy to break them so higher boiling point 
27
What is the ease of ignition?
The easier it is to turn into a vapour, the easier it is to ignite
28
What does shorter chain length do to the ease of ignition? 
They have less intermolecular forces so easier to turn into a vapour so easier to ignite
29
What is viscosity?
How easy a fluid can flow
30
What liquid has a low viscosity?
Water - flow easily
31
What has the longest carbon chain? 
Bitumen since it has the strongest intermolecular forces
32
What happens if you go down the fraction?
The viscosity increases because the chain length is longer, so there is stronger into molecular forces between molecules to break through
33
What does crude oil contain most of?
Alkanes
34
What do homologous series chemicals have the same?
General formula
35
What do homologous series chemicals have that is similar?
Chemical properties
36
What do homologous series chemicals differ from ?
By CH2 in their molecular formula
37
What do homologous series chemicals show?
A gradual trend in physical properties
38
What are alkanes?
Saturated hydrocarbons
39
Alkenes all end in…
-ane
40
What are 3 common alkanes?
Methane
Ethane
Propane
41
What do general formulas show?
The ratio of atoms present in the homologous series 
42
What do you do for alkane formulas?
Doubles then add 2
43
What does longer molecule mean?
Stronger intermolecular forces
44
What are alkenes?
Un saturated hydrogen carbons
45
What is the general formula for alkenes?
Double it
46
What chained fractions can be cracked?
Fuel oil and bitumen
47
Why are chained fractions cracked?
Into smaller more useful alkanes and alkenes
48
What can be produced when cracking?
Hydrogen
49
What are alkenes used for?
To make polymers
50
What is the general formula calculation for alkenes?
Add to get 10 for the first 2 numbers and add to get 22 for the second numbers
51
What is complete combustion?
Hydrocarbons react with oxygen when they burn
52
What type of reaction is complete combustion?
Oxidisation
53
What happens in complete combustion?
Energy is released
54
When does complete combustion occur?
When there is plentiful supply of oxygen
55
What is produced in complete combustion?
Carbon dioxide and water
56
What is methane?
A non renewable fossil fuel found in natural gas
57
What is it when the Bunsen burner hole is open and there is lots of oxygen?
Complete combustion
58
What is it when the Bunsen burner hole is closed and there is limited oxygen?
Incomplete combustion
59
When does incomplete combustion occur?
When there is limited supply of oxygen
60
What is produced in incomplete combustion?
Water, carbon monoxide and carbon (soot)
61
What is released in incomplete combustion?
Less energy than complete combustion
62
How many electrons are in the outside shell in group one elements?
1
63
What are group one elements call?
Alkaline metals
64
What are physical properties of group 1?
Malleable
Low melting point
Low density
Soft
65
What are chemical properties of group 1 elements?
Reactive
Oxidise easily
React with cold water
66
How does the reactivity increase in group 1?
Down the group
67
What do all group 1 form?
The same reaction
68
What happens as the the distance between the outer shell electrons and the nucleus in the group 1 elements?
The alkali metal gets more reactive because the outside shell electron is easier to remove
69
What are group 0 elements called?
Noble gases
70
What are properties of helium?
It has very low density and is non flammable
71
What is the use of helium?
Fill weather balloons
Air ships
Balloons
72
What are group 0 unreactive?
Because they have a full outer shell
73
What is the use of neon?
Advertising signs
74
What does neon do?
Gives a red orange light when electricity is passed through it
75
What are uses of Aragon?
Provide an inert atmosphere for welding and in filament lamps
76
What are group 7 called?
Halogens
77
What is the appearance of the halogen chlorine?
Green gas
78
What is the appearance of the halogen bromine?
Red brown liquid
79
What is the appearance of the halogen iodine?
Grey solid, purple gas
80
What does the melting point of halogens do as you go down the group?
Increases
81
What does the density of halogens do as you go down the group?
Increases
82
What happens as you down group 7 and the distance between the outside shell and the nucleus increases?
The attraction of the extra negative electron and positive nucleus is less
83
What is group 7?
Less reactive
84
What will displace in reactions of halogens and halide ions?
The more reactive halogen will displace a less reactive halide in the solution
85
What can chlorine displace?
Bromine and iodine as it is more reactive
86
What can iodine not displace?
Chloride or bromide as it is least reactive
87
What can bromine displace? And what can it not?
Bromine can displace iodine but not chloride as it is in the middle
88
What are some green house gases?
Carbon dioxide
Water vapour
Methane
89
What does green house gases do?
They absorb heat energy radiated by the Earth, and re-radiate it back to Earth, causing the Earth and atmosphere to heat up, increasing the greenhouse effect 
90
What is pollution caused by?
Sulphur impurities in fuels burn and react with oxygen to produce sulphur dioxide 
91
What is sulfur dioxide and what does it produce?
Sulphur dioxide is an acidic gas. It can dissolve in cloud and produce acid rain.
92
What does acid rain dissolve in and what does it do?
Rivers and lakes which decreases the pH
93
What does acid rain kill?
Fish, insects plants, and other aquatic life
94
What does acid rain damage and corrode?
Buildings, and statues and metals
95
How are oxides of nitrogen produced?
Car engines are so hot, they caused the nitrogen and oxygen in the air to react
96
Why is nitrogen dioxide a toxic gas?
It can cause respiratory diseases such as bronchitis
97
What does nitrogen dioxide dissolve in and what does it contribute to?
Rain clouds to acid rain
98
What is carbon monoxide?
Toxic gas that is colourless and odourless
99
What does carbon monoxide react with?
Haemoglobin in the red blood cells so that the haemoglobin cannot carry oxygen and so less oxygen can get into the brain
100
What is soot?
Carbon particles of unburnt carbon
101
How does soot build up?
In engines and boilers, so it reduces the efficiency and increases other pollutants
102
What are the negatives of soot?
It can aggravate asthma and other respiratory problems, and it makes buildings dirty
