4.5 - Organic I Flashcards
(117 cards)
1
Q
what is crude oil
A
a mixture of hydrocarbons, compounds of hydrogen (H) and carbon (C)
2
Q
why does crude oil boil over a large range of temperatures
A
the different hydrocarbons in it come in a huge variety of shapes and sizes
3
Q
why do you need to separate crude oil into fractions which contain similarly used molecules
A
most of the hydrocarbons are useful, but for different purposes
4
Q
what is each fraction of crude oil
A
a mixture of similar hydrocarbons with similar boiling points
5
Q
what happens to the fractions as the boiling points increase
A
they get darker in colour
they get more viscous
6
Q
what is the boiling point of refinery gases
A
low
7
Q
what is the molecular mass of refinery gases
A
low
8
Q
what is the colour of refinery gases
A
light (colourless)
9
Q
what is the viscosity of refinery gases
A
low
10
Q
what is the use of refinery gases
A
fuel for home cooking (and home heating)
11
Q
what is the boiling point of gasoline
A
low but higher than refinery gases
12
Q
what is the molecular mass of gasoline
A
low but higher than refinery gases
13
Q
what is the colour of gasoline
A
light but darker than refinery gases (pale yellow)
14
Q
what is the viscosity of gasoline
A
low but higher than refinery gases
15
Q
what is the use of gasoline
A
fuel for cars
16
Q
what is the boiling point of kerosene
A
on the highest end of low as is higher than refinery gases and gasoline
17
Q
what is the molecular mass of kerosene
A
on the highest end of low is higher than refinery gases and gasoline
18
Q
what is the colour of kerosene
A
darker than gasoline
19
Q
what is the viscosity of kerosene
A
on the highest end of low as is higher than refinery gases and gasoline
20
Q
what is the use of kerosene
A
fuel for aircraft (and industrial heating)
21
Q
what is the boiling point of diesel
A
on the lowest end of high as is higher than refinery gases, gasoline and kerosene
22
Q
what is the molecular mass of diesel
A
on the lowest end of high as is higher than refinery gases, gasoline and kerosene
23
Q
what is the colour of diesel
A
darker than kerosene (dark yellow)
24
Q
what is the use of diesel
A
fuel for trains (and trucks)
25
what is the boiling point of fuel oil
second highest as is higher than refinery gases, gasoline, kerosene and diesel
26
what is the molecular mass of fuel oil
second highest as is higher than refinery gases, gasoline, kerosene and diesel
27
what is the colour of fuel oil
darker than diesel (brown)
28
what is the viscosity of fuel oil
second highest as is higher than refinery gases, gasoline, kerosene and diesel
29
what is the use of fuel oil
fuel for ships
30
what is the boiling point of bitumen
high and the highest as is higher than refinery gases, gasoline, kerosene, diesel and fuel oil
31
what is the molecular mass of bitumen
high and the highest as is higher than refinery gases, gasoline, kerosene, diesel and fuel oil
32
what is the colour of bitumen
darkest (black)
33
what is the viscosity of bitumen
high and the highest as is higher than refinery gases, gasoline, kerosene, diesel and fuel oil
34
what is the use of bitumen
making roads (and roofs)
35
how are each of the fractions separated from crude oil
by fractional distillation
36
where is the fractionating column hotter and colder
hotter at bottom and colder at top
37
what is the order of the fractionating column top to bottom/ cold to hot
refinery gases
gasoline
kerosene
diesel
fuel oil
bitumen
38
mnemonic to remember order of fractionating column top to bottom
rad
gangs
kill
dads
feeding
babies
39
how does fractional distillation of crude oil work
1- heated crude oil vapours enter the column
2- vapours rise until they reach their boiling point when they condense
3- different vapours condense at different heights due to their different boiling points
4- similar vapours condense together as a franction
40
what are fractions
mixtures containing the hydrocarbons that boil in a particular temperature range
41
what are alkanes
hydrocarbons that fit the general formula CnH2n+2
42
what are alkanes made of
simple molecules containing C and H atoms held together by covalent bonds
43
what is the pattern of the names of alkanes
-the start of the name shows how many carbon atoms it has
-the end of the name is '-ane' to show it is an alkane
44
what is the formula of the first alkane - methane
CH4
45
what is the name of the first alkane
methane
46
what is the bonding of the first alkane - methane
bonding: H
¦
H----C----H
¦
H
47
what is the formula of the second alkane - ethane
C2H6
48
what is the name of then second alkane
ethane
49
what is the bonding of the second alkane - ethane
bonding: H H
¦ ¦
H------C--------C-------H
¦ ¦
H H
50
what is the formula of the third alkane - propane
C3H8
51
what is the name of the third alkane
propane
52
what is the bonding of the third alkane - propane
bonding: H H H
¦ ¦ ¦
H-----C------C------C------H
¦ ¦ ¦
H H H
53
what is the formula of the fourth alkane - butane
C4H10
54
what is the name of the fourth alkane
butane
55
what is the bonding of the fourth alkane - butane
bonding: H H H H
¦ ¦ ¦ ¦
H-----C-----C------C------C-----H
¦ ¦ ¦ ¦
H H H H
56
what is the formula of the fifth alkane - pentane
C5H12
57
what is the name of the fifth alkane
pentane
58
what is the bonding of the fifth alkane - pentane
bonding: H H H H H
¦ ¦ ¦ ¦ ¦
H----C------C----C-----C----C----H
¦ ¦ ¦ ¦ ¦
H H H H H
59
after the first five alkanes what pattern do the other names follow
the 2D shapes - hexane, heptane, octane etc
60
what is a displayed formula
a diagram showing the positions of every atom and bond
61
what is an example of a displayed formula using butane
bonding: H H H H
¦ ¦ ¦ ¦
H----C-----C----C-----C-----H
¦ ¦ ¦ ¦
H H H H
62
what is a structural formula
shows the structure of the molecule in one line, read from left to right like a word
63
what is an example of a structural formula using butane
CH3CH2CH2CH3
64
what is a molecular formula
only shows how many carbon and hydrogen atoms there are
65
what is an example of a molecular formula
C4H10
66
what is an empirical formula
only shows the simplest whole-number ratio of carbon to hydrogen
67
what is an example of an empirical formula using butane
C2H5
68
what type of series are alkanes
homologous series
69
what is a homologous series
a family of molecules which have:
- similar chemical reactions
-trends in physical properties (boiling points, viscosity, colour)
-the same general formula
70
what are isomers
molecules with the same molecular formula but different structural formula
71
what do the isomers of C4H10 look like
1: H H H H 2. H H H
¦ ¦ ¦ ¦ ¦ ¦ ¦
H---C----C---C----C---H H------C-----C----C-----H
¦ ¦ ¦ ¦ ¦ ¦ ¦
H H H H H ¦ H
H----C----H
¦
H
72
what do the isomers of C5H12 look like
1. H H H H H
73
how do you know when two structures are not isomers
you cannot make isomers by just bending the molecule
what makes isomers different is the branching of the carbon chain
74
why are most alkanes used as fuels
they release a lot of energy when combusted
75
what are the two types of combustion alkanes can undergo
complete combustion
incomplete combustion
76
when does complete combustion occur
when there is excess oxygen
77
what does complete combustion produce
only CO2 and H2O
78
what is the equation for complete combustion
alkane + oxygen --> carbon dioxide + water
79
what would the word and chemical equations for complete combustion of propane look like
propane + oxygen --> carbon dioxide + water
C3H8 5O2 3CO2 4H2O
80
when does incomplete combustion occur
when there is not enough excess oxygen
81
what does incomplete combustion produce
carbon monoxide (CO) - a toxic gas which lowers oxygen-carrying capacity of blood
soot (C) - which causes lung diseases
it also releases less energy so it makes the alkane less useful as a fuel
82
what are the names of the three significant pollutants that the combustion of alkanes as fuels release into the atmosphere
carbon dioxide (CO2)
nitrogen oxides (NOx)
sulphur dioxide (SO2)
83
what are the three significant pollutants that the combustion of alkanes as fuels release into the atmosphere in detail)
carbon dioxide - this forms directly from the combustion of the
alkane fuel. it is a greenhouse gas that traps heat in
the atmosphere and causes climate change
nitrogen oxides - this family of compounds form when nitrogen from
when nitrogen from the air combusts. usually
nitrogen doesn't combust but car engines are really
hot. they dissolve in rainwater to form acid rain,
which corrodes structures and is harmful to plant
and aquatic life
sulphur dioxide - this forms when sulphur impurities in the fuel
combust. like nitrogen oxides, it also dissolves in
rainwater to form acid rain
84
how do alkanes react with halogens
by swapping one hydrogen for one halogen atom
85
what does an alkane reaction with a halogen look like as a diagram equation
--ethane (C2H6) and bromine (Br2)
86
what are the two things about an alkane and halogen reaction you need to know
- it is a substitution reaction - because the H swaps with the (Br)
- the reaction requires UV light - because the alkane si pretty
unreactive
87
why is an alkane and halogen reaction a substitution reaction
because the H swaps with the halogen (Br)
88
why does an alkane and halogen reaction require a UV light
because the alkane is pretty unreactive
89
what lengths of alkanes does crude oil usually contain
more longer alkanes than shorter ones
90
what length of alkane is more useful
shorter
91
how do you get around the fact crude oil contains more long alkanes even though the short alkanes are more useful
take the longer alkanes and do cracking
92
what does cracking do
breaks down longer alkanes into smaller, more useful ones
93
what conditions is cracking conducted under
temperature - 650 degrees C
catalyst - aluminium oxide (Al2O3)
it can be conducted without a catalyst but far more energy would need to be provided
94
what is the general cracking equation
long alkane --> shorter alkane + alkene
95
what would an equation for cracking pentane (C5H12) look like
equation: H H H H H H H H H H
¦ ¦ ¦ ¦ ¦ ¦ ¦ ¦ ¦ ¦
H---C----C-----C---C---C---H -------> H---C----C--C----H + C===C
¦ ¦ ¦ ¦ ¦ ¦ ¦ ¦ ¦ ¦
H H H H H H H H H H
C5H12 ----------> C2H6 + C3H6
pentane ethane propene
96
what are the two things that must happen for cracking to be possible
- it makes an alkane and an alkene
- the numbers of C and H atoms add up
97
how do alkanes react with halogens
by swapping one hydrogen atom for one halogen atom
98
what does ethane (C2H6) reacting with bromine (Br2) look like
equation: H H Br H H H
¦ ¦ ¦ ¦ ¦ ¦
H---C----C-----H + Br -----> H-----C-------C-----H + Br
¦ ¦ ¦ ¦
H H H H
C2H6 + Br2 -----> C2H5Br + HBr
99
what type of reaction is an alkane with a halogen
substitution reaction - because the hydrogen swaps with the halogen
100
what does the reaction between an alkane and halogen need
a UV light - because the alkane is pretty unreactive
101
what are alkenes
hydrocarbons that fit the general formula CnH2n
102
how are alkenes similar and different to alkanes
they work like alkanes but they have one C=C double bond
103
what is the pattern of alkenes
-the start of the name shows how many carbon atoms it has
-the end of the name is '-ene' to show it is an alkene and has the C=C double bond
104
what type of series are alkenes
homologous
105
what would the structural formula of butene look like
CH2=CHCH2CH3
106
what is the formula of the first alkene - ethene
C2H4
107
what is the name of the first alkene
ethene
108
what is the bonding of the first alkene - ethene
bonding: H H
¦ ¦
C==C
¦ ¦
H H
109
what is the formula of the second alkene - propene
C3H6
110
what is the name of the second alkene
propene
111
what is the bonding of the second alkene - propene
bonding: H H H
¦ ¦ ¦
C==C---C----H
¦ ¦
H H
112
what is the formula of the third alkene - butene
C4H8
113
what is the name of the third alkene
butene
114
what is the bonding of the third alkene - butene
bonding: H H H H
¦ ¦ ¦ ¦
C===C----C---C----H
¦ ¦ ¦
H H H
115
what is the formula of the fourth alkene - pentene
C5H10
116
what is the name of the fourth alkene
pentene
117
what is the bonding of the fourth alkene - pentene
bonding: H H H H H
¦ ¦ ¦ ¦ ¦
C==C---C---C--C---H
¦ ¦ ¦ ¦
H H H H
