Level 1 Physical Science: Carbon Chemistry Flashcards
(224 cards)
1
Q
How are ions formed
A
Ions are formed when atoms gain or lose electrons resulting in a full outer shell (valence shell)
2
Q
Is a cation positive or negative
A
positive
3
Q
Is a anion positive or negative
A
negative
4
Q
What is the atomic number a measurement of
A
the number of protons in an atom
5
Q
What is a group (periodic table)
A
the vertical columns of elements
6
Q
What is a period
A
the horizontal rows of elements
7
Q
how many electrons are in the 1,2,3 shells of an atom
A
in the first shell is two, in the second & third shells is eight
8
Q
why does an electron want a full valence shell
A
because it will become stable
9
Q
How do atoms get a full valence shell
A
by gaining or losing electrons
10
Q
What happens to an atom when it loses or gains electrons
A
it becomes an ion
11
Q
what is a polyatomic ion’s (made of many atoms) suffix (part at the end of the name of an ion for example sulfATE)
A
-ate
12
Q
what is a negative monatomic ion’s (made of only one atom) suffix (part at the end of the name of an ion)
A
-ide
13
Q
what is a positive ion’s (the metals & hydrogen) suffix (part at the end of the name of an ion)
A
named after the atom for example a calcium ion is just called: “calcium ion”
14
Q
What happens when a cation bonds to an anion
A
an ionic compound is formed
15
Q
When are covalent bonds formed
A
Covalent bonds are formed when atoms SHARE electrons in their valence shell.
16
Q
What does an ‘ionic bond’ mean
A
the force of attraction that holds ions together in an ionic substance. These bonds form due to the strong electrostatic attractions between oppositely charged ions.
17
Q
What is a covalent bond
A
the chemical bond characterised by the sharing of one or more pairs of electrons between two atoms.
18
Q
What is a polyatomic ion
A
an ion made of more than one atom.
19
Q
does a chemical compound formed during a chemical reaction have an overall charge
A
no
20
Q
why is carbon so important
A
because:
it easily forms long chained molecules.
It has its own cycle in nature (carbon cycle).
Carbon compounds are found in fuels, alcohols & plastics.
Crude oil is made up of carbon compounds.
It is atomic #6, =6 protons, 6 electrons.
It has its own branch of chemistry called organic chemistry.
Life as we know it is ‘carbon based’
Carbon has 4 valence electrons so it will always make 4 COVALENT BONDS, this makes it very versatile.
21
Q
How does carbon bond
A
Carbon forms 4 ‘COVALENT BONDS’.
22
Q
When do COVALENT BONDS occur
A
COVALENT BONDS occur when NON-METAL atoms SHARE electrons so that they can fill their valence shell. This makes the atoms STABLE.
23
Q
How many valence electrons does carbon has
A
Carbon has 4 valence electrons, this means they can bond with up to 4 other atoms to fill their valence shell.
24
Q
What do organic compounds & carbon families contain
A
organic compounds contain carbon & hydrogen plus a range of other atoms including: O, N, S, Cl, Br & F
25
What are hydrocarbons
Hydrocarbons are molecules that only contain CARBON and HYDROGEN. They can be split into two categories.
26
What are the two categories hydrocarbons can be split into
'Saturated' hydrocarbons and 'Unsaturated' hydrocarbons.
27
What is a 'Saturated' hydrocarbon
Saturated hydrocarbons contain only SINGLE carbon-carbon bonds. E.g Alkanes
28
What is a 'Unsaturated' hydrocarbon
Unsaturated hydrocarbons contain a DOUBLE carbon=carbon bond. E.g Alkenes.
29
What is an ALKANE
Alkanes are SATURATED hydrocarbons, containing only C-C bonds.
30
What organic family are ALKANES in?
The simplest organic family
31
What is the general formula for an ALKANE
CnH2n+2 (where 'n' is the number of carbon atoms in the molecule)
32
What is the simplest alkane
methANE
33
what does the 'meth' in methane tell us?
It tells us the number of CARBONS in the chain
34
what does the 'ane' in methane tell us?
It tells us it is a member of the alkANE family
35
How many carbons are in the chain if the suffix is Meth-
1
36
How many carbons are in the chain if the suffix is Eth-
2
37
How many carbons are in the chain if the suffix is Prop-
3
38
How many carbons are in the chain if the suffix is But-
4
39
How many carbons are in the chain if the suffix is Pent-
5
40
How many carbons are in the chain if the suffix is Hex-
6
41
How many carbons are in the chain if the suffix is Hept-
7
42
How many carbons are in the chain if the suffix is Oct-
8
43
What is the molecular formula for Methane
CH₄
44
What is the full structural formula for Methane
H
|
H - C - H
|
H
45
What is the condensed formula (squashing the structural formula into a single line) for Methane
CH₄
46
What is the condensed formula (squashing the structural formula into a single line) for Ethane
CH₃CH₃
47
What is the condensed formula (squashing the structural formula into a single line) for Propane
CH₃CH₂CH₃
48
What is the condensed formula (squashing the structural formula into a single line) for Butane
CH₃CH₂CH₂CH₃
49
What is the condensed formula (squashing the structural formula into a single line) for Pentane
CH₃CH₂CH₂CH₂CH₃
50
What is the condensed formula (squashing the structural formula into a single line) for Hexane
CH₃CH₂CH₂CH₂CH₂CH₃
51
What is the condensed formula (squashing the structural formula into a single line) for Heptane
CH₃CH₂CH₂CH₂CH₂CH₂CH₃
52
What is the condensed formula (squashing the structural formula into a single line) for Octane
CH₃CH₂CH₂CH₂CH₂CH₂CH₂CH₃
53
What is the molecular formula for Ethane
C₂H₆
54
What is the molecular formula for Propane
C₃H₈
55
What is the molecular formula for Butane
C₄H₁₀
56
What is the molecular formula for Pentane
C₅H₁₂
57
What is the molecular formula for Hexane
C₆H₁₄
58
What is the molecular formula for Heptane
C₇H₁₆
59
What is the molecular formula for Octane
C₈H₁₈
60
What is the full structural formula for Ethane
H H
| |
H - C - C - H
| |
H H
61
What is the full structural formula for Propane
H H H
| | |
H - C - C - C - H
| | |
H H H
62
What is the full structural formula for Butane
H H H H
| | | |
H - C - C - C - C - H
| | | |
H H H H
63
What is the full structural formula for Pentane
H H H H H
| | | | |
H - C - C - C - C - C - H
| | | | |
H H H H H
64
What is the full structural formula for Hexane
H H H H H H
| | | | | |
H - C - C - C - C - C - C - H
| | | | | |
H H H H H H
65
What is the full structural formula for Heptane
H H H H H H H
| | | | | | |
H - C - C - C - C - C - C - C - H
| | | | | | |
H H H H H H H
66
What is the full structural formula for Octane
H H H H H H H H
| | | | | | | |
H - C - C - C - C - C - C - C - C - H
| | | | | | | |
H H H H H H H H
67
What does 'crude' mean
'CRUDE' means in a natural or raw state, not yet processed or refined
68
What is petroleum (crude oil) a mixture of
Petroleum (known as crude oil) is a mixture of many different HYDROCARBONS with molecules containing up to 30 carbons in the chain.
69
Where are ALKANES found
ALKANES are found in crude oil.
70
What is the first physical property of ALKANES
1. ALKANES are NOT SOLUBLE in water, they float on top of water in a layer.
71
Why do ALKANES float on top of water in a layer?
Because there is little attraction between water molecules and ALKANE molecules. Water cannot overcome the forces of attraction already holding ALKANES together.
72
What is the second physical property of ALKANES
2. The LONGER the ALKANE chain, the HIGHER the melting point and boiling point. (this applies for ALL hydrocarbons)
73
Why do longer ALKANE chains have HIGHER melting & boiling points?
Because longer ALKANE chains have more FORCES OF ATTRACTION holding them together than shorter ALKANE chains, so more heat energy is needed to break them apart. So, for example, Hexane (6 carbons) has a higher melting point than butane (4 carbons).
74
What can we call forces of attraction? And why do we call them that?
'INTERMOLECULAR forces' because they occur BETWEEN MOLECULES. 'INTER' means between. (the INTERislander travels between islands)
75
What is paraffin wax composed of
alkanes with 20-40 carbons in their chains.
76
between Methane-Butane what will be at room temp? (Gases, Solids or Liquids)
Methane-Butane=gases at room temperature (1-4 carbons)
77
Between Pentane-C₁₈H₃₈ what will be at room temp? (Gases, solids or liquids)
Pentane-C₁₈H₃₈=liquids at room temperature (5-18 carbons)
78
between C₁₉H₄₀-onwards what will be at room temp? (gases, solids or liquids)
C₁₉H₄₀-onwards=solids at room temperature (19+ carbons)
79
What are the key points on Boiling points: Molecules with a small carbon chain
The chains are small
The molecules have a small molecular mass
Because they are so small, there are few weak intermolecular forces between molecules.
It takes only a small amount of heat energy to break these forces and turn the LIQUID into a GAS.
Hence: These molecules have a lower boiling point.
80
What are the key points on Boiling points: Molecules with a long carbon chain
The chains are looooong.
The molecules have a bigger molecular mass.
Because they are so long, there are many more weak intermolecular forces between the molecules.
It takes a large amount of heat energy to break the high number of these forces & turn the LIQUID into a GAS.
Hence: These molecules have a higher boiling point.
81
What are ALKENES another _________ __________ of
ALKENES are another organic family.
82
What do ALKENES contain?
They contain a COVALENT double carbon bond (C=C)
83
What do we call C=C
We call C=C the 'functional group' (the reactive part of the molecule).
84
What is the general formula for ALKENES
CnH2n
85
What does having a C=C bond make ALKENES?
Having a C=C bond makes alkenes UNSATURATED (because more atoms can be added to the structure if we break the bond).
86
What is the simplest ALKENE
The simplest ALKENE is Ethene
87
What does the Eth in ethene tell us (ALKENES names differ slightly to ALKANES)
It tells us the number of carbons in the chain
88
What does the ene in ethene tell us (ALKENES names differ slightly to ALKANES)
It tells us it's a member of the alkENE family.
89
In relation to ALKENES what does Carbon always make
Carbon always makes 4 BONDS (i.e it ALWAYS has 4 sticks coming out of it in diagrams)
90
alkENE diagrams look a bit ________ to alkANE diagrams.
alkENE diagrams look a bit different to alkANE diagrams.
91
In relation to ALKENES what do we only need to know about
We only need to know about the first 2 alkENEs; ETHene and PROPene.
92
In relation to ALKENES what doesn't exist?
Methene does not exist because we need a minimum of 2 carbon atoms to make a C=C bond.
93
What is the molecular formula of Ethene
C₂H₄
94
What is the molecular formula of Propene
C₃H₆
95
What is the full structural formula of Ethene
H H
| |
C = C
| |
H H
96
What is the full structural formula of Propene
H H H
| | |
H - C - C = C
| |
H H
97
What is the condensed formula of Ethene
CH₂CH₂
98
What is the condensed formula for Propene
CH₃CHCH₂
99
What chemical do we use to test for an ALKENE
To test for an alkene, we use a chemical called 'Bromine Water (Br)₂
100
What colour is Br₂
Orange
101
What will happen to Br₂ when mixed with ALKENES?
Br₂ will decolourise (turn colourless) when mixed with ALKENES.
102
What happens to an ALKENE when mixed with Br₂
The double C=C bond breaks & a single C-C bond is made. The molecule goes from UNSATURATED to SATURATED.
103
What do the two BR atoms do when mixed with ALKENES
The 2 Br atoms attach to the free bonds on the carbons.
104
What is the structural equation for mixing Br₂ with an ALKENE
H H H H
\ / | |
C = C + Br₂ ------> H - C - C - H
/ \ | |
H H Br Br
Ethene Bromine Water Colourless Alkane
(sometimes Ethene (The double bond
is drawn like this, breaks and a Br
with bonds on atom is added to
angles instead of each C atom)
straight up & down)
105
What is an important note to remember to do with testing for ALKENES using Bromine Water
ALKANES also react with 'orange Br₂ water' to go colourless... BUT it is a very SLOW reactions that needs UV light. An easy way to tell ALKANES & ALKENES apart is that ALKENES will decolourise Br₂ water RAPIDLY, ALKANES will not (unless you add UV light).
106
What are Polymers
Polymers are very large molecules made up of many small, REPEATING UNITS called MONOMERS.
107
What are some ALKENES use as
Some ALKENES are used as MONOMERS.
108
What do MONOMERS do in order to form a polymer?
The MONOMERS link together with 'covalent bonds' to form the polymer
109
What is a key point about the double bond in ALKENES
The double bond in an ALKENE is a very REACTIVE bond, which is easily broken by HEAT and PRESSURE in the presence of a CATALYST.
110
What is possible after the double bond is broken in POLYMERISATION
Once the double bond is broken, it is possible for the individual small molecules to link together to produce a POLYMER. (this process is called POLYMERISATION)
111
What is POLYMERISATION
POLYMERISATION is where the double bond in an ALKENE is broken and this enables the individual small molecules to link together to produce a POLYMER.
112
What is the POLYMERISATION CAST
H H H H
\ / | |
C = C - C C - ---------->*
/ \ | |
H H H H
"The Monomer" "The repeating unit"
Has a double bond
~ --------------------------~
"The conditions"
Heat, pressure, catalyst
H H H H H H H H
| | | | | | | |
* ------> - C - C - C - C - C - C - C - C -
| | | | | | | |
H H H H H H H H
"A section of Polymer"
This one shows 4 repeating units linked up.
This Polymer is called polyETHENE (because the monomer was ethene)
113
What is a key point on the C=C bond (double bond)
The C=C bond is very reactive. In the presence of heat, pressure and a catalyst the C=C covalent bond breaks and forms a single C-C bond and a spare single bond. This can be covalently bonded to a monomer to make a long chain.
114
Why do ALKANES not form polymer chains
Alkanes are SATURATED molecules. The single covalent bonds in alkanes are STABLE and are not very reactive (unlike an alkene bond)
115
Explain why alkenes can be used to make polymers but alkanes cannot.
Alkenes have a (reactive) double covalent bond between 2 carbon atoms. (Under high temperatures, high pressure & catalytic conditions) the double bond can be broken, resulting in a single covalent bond a spare single bond that can be covalently bond to the next monomer to form a long chain polymer.
\ / | | | | | |
C=C -------> • C-C • ( -C-C-C-C-)n
/ \ | | | | | |
Alkanes have only single covalent bonds between carbon atoms, which are unreactive (in these conditions), so do not form polymers.
116
What are the key points to do with 'Polymers as Plastics'
Polymers formed from Alkenes have special properties.
They consist of HUGE numbers of long chain molecules that overlap each other.
Because these polymers are so long, the intermolecular forces between the neighbouring molecules are strong.
Because of this, polymers are TOUGH substances... but are easily moulded too. We describe them as PLASTICS.
117
Polypropene (polypropylene) has many uses that are linked to its chemical and physical properties. Name TWO uses of polypropene. Link each use to TWO physical and/or chemical properties of polypropene.
Low chemical reactivity (e.g with air, water and living organisms). (But susceptible to UV degradation).
High tensile strength/strong.
Insolubility in water/does not absorb moisture.
Ability to be moulded or extruded into a wide range of shapes with moderate heating due to high melting point (about 160°C).
Insulator.
Low density/light weight and floats.
Recyclable.
118
What is the general formula for Alkanes (straight chain)
CnH2n+2
119
What is the general formula for Alkenes
CnH2n
120
What are the similarities between Alkanes and Alkenes
Carbon and Hydrogen atoms are COVALENTLY BONDED to each other (could be from (b))
121
What is the quality an ALKANE has that makes it different from an ALKENE
ALKANES are SATURATED hydrocarbon molecules, where EACH CARBON ATOM HAS 4 SINGLE COVALENT BONDS.
122
What is the quality an ALKENE has that makes it different from an ALKANE
ALKENES are UNSATURATED hydrocarbon molecules containing mostly single covalent bonds, but also a CARBON-CARBON DOUBLE BOND.
123
What are the key points for an ALKANES chemical bonding linked to property & use?
Alkanes do NOT HAVE A FUNCTIONAL GROUP, so they are generally CHEMICALLY UNREACTIVE/READILY COMBUST (PROPERTY). Alkanes are commonly used as FUELS (USE), because, while they are mostly unreactive, they do UNDERGO COMBUSTION REACTIONS SINCE SINGLE BONDS DO NOT REQUIRE AS MUCH ENERGY TO BREAK. So a lot of energy is released as they combust.
124
What are the key points for an ALKENES chemical bonding linked to property & use?
The DOUBLE BOND in alkenes is a FUNCTIONAL GROUP & is EASILY BROKEN, so alkenes are CHEMICALLY REACTIVE (PROPERTY). Since alkenes are chemically reactive, they also undergo other chemical reactions, & are therefore commonly USED TO MAKE OTHER ORGANIC MOLECULES SUCH AS POLYMERS (USE) SINCE THE DOUBLE BOND EASILY BREAKS TO FORM LONG CHAIN.
125
Explain the difference between the 2 formulae for the ethene molecule, the molecular formula & the structural formula
The structural formula (which is CH₂=CH₂ for ethene) shows the arrangement of atoms & bonding in the molecule. The molecular formula (which is C₂H₄ for ethene) gives the number & types of atoms in each molecule.
126
Explain what is meant by an unsaturated carbon compound
An unsaturated carbon compound contains a double (or triple) bond between two carbon atoms.
127
Explain why alkenes are able to form polymers, while alkanes do not
Alkenes have a double bond & so under certain conditions such as heat, pressure & catalysts the bond can break creating links for the alkene to bond to other alkenes which creates a long chain called a polymer. An alkane does not have a double bond so cannot form a polymer.
128
What are the key points on the problem with plastic
Polymers have single C-C bonds & are therefore alkanes.
Since neither alkanes nor polymers have 'functional group' (a reactive group) they are UNREACTIVE with water so WILL NOT BREAK DOWN in water.
There is also very little attraction between ALKANE molecules and WATER molecules.
Polymers are INSOLUBLE in water & are NON-BIODEGRADABLE.
This is why there is so much plastic FLOATING on the surface of the ocean (in massive plastic islands called 'GYRES').
129
What is crude oil a mixture of
Crude oil is a mixture of many different hydrocarbons.
130
What is Fractional distillation
Fractional distillation is a process used to separate the hydrocarbon mixture into USEFUL fractions (i.e groups of alkanes with similar sized molecules), such as petrol, diesel, kerosene and jet fuel.
131
What are molecules separated by for fractional distillation
Molecules are separated based on their BOILING POINTS.
132
What is an important thing to remember to do with fractional distillation?
The longer the carbon chain, the larger the 'molecular mass' (mass of the molecule) and so the higher the boiling point. The fractional distillation tower can be more than 50m tall.
133
The ________ the carbon chain the ________ the 'molecular mass' (mass of the molecule) and so the higher the boiling point.
The LONGER the carbon chain, the LARGER the 'molecular mass' (mass of the molecule) and so the higher the boiling point.
134
How many carbons, what is the average boiling point and what is it used for: Gases
1-4 carbons <40°C. Used as fuels for heating, cooking and manufacture of plastics. E.g Methane, Ethene etc
135
How many carbons, what is the average boiling point and what is it used for: Gasoline
5-12 carbons 40-200°C. Used as fuels for vehicles, LPG, various petrochemicals and solvents. E.g Octane``
136
How many carbons, what is the average boiling point and what is it used for: Light Distillates
12-16 carbons. 200-300°C. Used as aviation fuel, naphthas, solvents, kerosene and refined oils.
137
How many carbons, what is the average boiling point and what is it used for: Intermediate Distillates
15-18 carbons. 250-350°C. Used as diesel fuel and heavy fuel for ships and power stations.
138
How many carbons, what is the average boiling point and what is it used for: Heavy Distillates
16-20 carbons. 300-350°C. Used as lubricating oils, wax, grease and petrochemicals.
139
How many carbons, what is the average boiling point and what is it used for: Residues
>20 carbons. More than 350°C. Used as bitumen for roads, asphalt, petroleum jelly.
140
Explain why crude oil must be fractionally distilled before it can be used
Because crude oil contains many different hydrocarbons that must be separated into their fractions to be properly utilised
141
Name TWO of the fractions obtained from the fractional distillation tower, and describe ONE use for each
1) Fraction: Liquid petroleum gas, used to power barbeques & for heating
2) Fraction: Bitumen, used for roads & can be used for roofs
142
How do you get an alkene from an alkane
By 'Cracking'
143
What do we do to an alkane during cracking
During 'CRACKING' we BREAK (or 'crack') a large ALKANE into smaller, more useful pieces. The products are a SMALLER ALKANE and an ALKENE.
144
What is a key thing to remember about the # of C and H atoms to do with cracking
Since the number of C and H atoms cannot change, we cannot make 2 ALKANES as we would be 2 H atoms short.
145
Why do we need cracking? In relation to ALKENE availibility
While ALKENES do exist in nature, they are not found in a form (or on a scale) we can use to make plastics, which is why we need cracking
146
What can cracking be used to produce (Answer is NOT an ALKANE and ALKENE)
Cracking can be used to produce: ethene, propene & butene. These are MONOMERS (building blocks) for the plastics industry.
147
What are ethene, propene and butene
MONOMERS (building blocks) for the plastics industry
148
What 2 things are needed for cracking to happen
Heat & a catalyst are needed to make it happen.
149
What is CRACKING a type of?
'Cracking' is a type of 'THERMAL DECOMPOSITION' reaction where one molecule breaks into two, USING HEAT.
150
Why do we need cracking (2 reasons)
1) to make alkenes
2) to make smaller alkanes
151
Why do LARGE alkanes not burn well?
1) because they have High boiling points
2) they do not flow easily
3) they are to hard to ignite (difficult to get oxygen into the flame for 'complete combustion')
This is why we need to CRACK them into smaller molecules. Octanes make good fuels (i.e petrol) so CRACKING is used to make octanes from bigger alkanes (as well as making alkenes for plastics)
152
Explain why smaller hydrocarbons are collected at the top of the fractional distillation tower
Because they have the lowest boiling point and therefore continue to evaporate up the tower without condensing and exiting until they reach their low boiling points at the top
153
Define the term 'homologous series'
homologous series means a group with the same general structure and characteristics and the same formula
154
How many carbons does methanol have
1
155
What is methanol's prefix
meth-
156
Molecular formula of methanol
CH₃OH
157
Structural formula of methanol
H OH
\ /
C
/ \
H H
158
Condensed structural formula of methanol
CH₃OH
159
How many carbons does ethanol have
2
160
What is ethanol's prefix
eth-
161
Molecular formula of ethanol
C₂H₅OH
162
Structural formula of ethanol
H H
| |
H - C - C - OH
| |
H H
163
Condensed structural formula of ethanol
CH₃CH₂OH
164
How many carbons does propanol have
3
165
What is propanol's prefix
prop-
166
Molecular formula of propanol
C₃H₇OH
167
Structural formula of propanol
H H H
| | |
H - C - C - C - OH
| | |
H H H
168
Condensed structural formula of propanol
CH₃CH₂CH₂OH
169
How many carbons does butanol have
4
170
What is butanol's prefix
but-
171
What is butanol's molecular formula
C₄H₉OH
172
What is butanol's Structural formula
H H H H
| | | |
H - C - C - C - C - OH
| | | |
H H H H
173
What is butanol's condensed structural formula
CH₃CH₂CH₂CH₂CH₂OH
174
What are alcohols a family of and what are they based on
ALCOHOLS are a family of carbon compounds that are based on the alkane chain, but with an -OH group attached to a carbon atom. The -OH groups replaces an H atom.
175
What are the bonds in ALCOHOLS
The bonds in alcohols are COVALENT BONDS.
176
What is ALCOHOLS general formula
CnH2n+1 OH
177
What are the first 2 alcohols in the series?
1) Methanol CH₃OH
2) Ethanol C₂H₅OH
178
What are methanol and ethanol
Methanol and ethanol are useful 'EMULSIFIERS' because they can mix with both water and oil (partially anyway). The -OH functional group of an alcohol is strongly attracted to water molecules. In contrast, alkanes & alkenes that do NOT mix with water because the C and H atoms are not attracted to water molecules.
179
Explain why alcohols are not hydrocarbons, but alkanes and alkenes are
Alcohols have a hydroxyl molecule as well as hydrogen & carbon molecule as well as hydrogen and carbon molecules so is therefore not a hydrocarbon while alkanes and alkenes are hydrocarbons as they only have hydrogen & carbon molecules.
180
What is a key point on the 'INTERMOLECULAR FORCES' between alcohol molecules and alkane molecules
The 'INTERMOLECULAR FORCES' between alcohol molecules are MUCH STRONGER than those between alkane molecules. More heat energy is required to break these bonds between alcohol molecules.
181
Because of The 'INTERMOLECULAR FORCES' between alcohol molecules being MUCH STRONGER than those between alkane molecules. And more heat energy is required to break those bonds between alcohol molecules. What does that mean methanol and ethanol are?
Because of this, methanol and ethanol are both LIQUIDS at room temperature, not gases.
182
What are the boiling points of both methanol and ethanol
The boiling points of methanol and ethanol are both below 100°C. These liquids are described as VOLATILE (or easily vaporised)
183
What is Ethanol production by fermentation
Ethanol (drinking alcohol) is made by a natural process called FERMENTATION. Fermentation is an enzyme controlled process which takes place:
1) between ROOM TEMPERATURE and 45°C
2) under ANAEROBIC conditions (no oxygen)
3) in the presence of yeast (which is a natural catalyst)
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What is yeast
Yeast is a LIVING organism & requires WARMTH and MOISTURE to carry out fermentation.
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What does yeast metabolise
Yeast metabolises (converts) the SUGAR to ALCOHOL when there is a LACK OF OXYGEN, via anaerobic respiration. Yeast die when oxygen levels become too high.
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What does fermentation convert?
Fermentation converts carbohydrates (usually sugar) into ethanol.
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What is the word equation for fermentation
yeast
Glucose ------------> ethanol + carbon dioxide gas
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What is the symbol equation for fermentation
yeast
C₆H₁₂O₆ ------------> 2C₂H₅OH + 2CO₂
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Solubility: For the substance: cyclohexane (alkane) is it soluble in water?
NOT soluble in water
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Solubility: For the substance: cyclohexane (alkane) is it soluble in oil?
IS soluble in oil
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Solubility: For the substance: cyclohexene (alkene) is it soluble in water?
NOT soluble in water
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Solubility: For the substance: cyclohexene (alkene) is it soluble in oil?
IS soluble in oil
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Solubility: For the substance: methanol (alcohol) (OH) is it soluble in water?
IS soluble in water
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Solubility: For the substance: methanol (alcohol) (OH) is it soluble in oil?
IS soluble in oil
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What is combustion of fuels
Fuels are substances that BURN. Burning is a COMBUSTION reaction. There are 2 types of combustion reactions: COMPLETE and INCOMPLETE.
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Complete combustion, supply amount of: Oxygen?
Plentiful supply (either in environment or in chemical structure)
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Incomplete combustion, supply amount of: Oxygen?
None, or limited
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Complete combustion, what type of: Flame
Clean, blue
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Incomplete combustion, what type of: Flame
Orange (due to specks of CARBON burning) dirty, sooty
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Complete combustion, what are the: Products
CO₂ and H₂O
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Incomplete combustion, what are the: Products
C (soot), CO (carbon monoxide), H₂O and some CO₂
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Complete combustion, what is the: Energy given off?
More heat energy than incomplete combustion
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Incomplete combustion, what is the: Energy given off?
Less heat energy than complete combustion
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Complete combustion, what is the: Bunsen flame
BLUE, air hole open
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Incomplete combustion, what is the: Bunsen flame
ORANGE, air hole closed
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What is INCOMPLETE combustion
This happens when there is NOT ENOUGH OXYGEN around for the fuel to burn cleanly. Soot (carbon) and carbon monoxide (CO) will be produced. There will also be some CO₂ and water made. ALKENES undergo incomplete combustion because the oxygen finds int harder to get into the C=C BOND, Kerosene and turpentine are alkenes.
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What is the balanced symbol equation for this COMPLETE combustion reaction:
Methane + Oxygen ------> carbon dioxide + water
CH₄ + 2O₂ --------> CO₂ + 2H₂O
O₂ H₂O
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What is the balanced symbol equation for this INCOMPLETE combustion reaction:
Methane + Oxygen ------> carbon monoxide + water
CH₄ + 15 O₂ --------> CO + 2H₂O
1/2 O₂
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Incomplete combustion of Butene:
Butene + oxygen -----> carbon + water
C₄H₈ + 2 O₂ --------> 4C + 4H₂O
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Incomplete combustion of Butene:
Butene + oxygen -------> carbon monoxide + water
C₄H₈ + 4 O₂ -----> 4CO + 4H₂O
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Write a balanced equation for the complete combustion of:
butanol + oxygen -----> carbon dioxide + water
C₄H₉OH + 6 O₂ -------> 4CO₂ +5H₂O
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Write a balanced equation for the complete combustion of:
heptane + oxygen ---------> carbon dioxide + water
C₇H₁₆ + 11 O₂ ------> 7CO₂ + 8H₂O
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Write a balanced equation for the incomplete combustion of:
octane + oxygen -------> carbon + water
C₈H₁₈ +45 O₂ ------> 8C + 9H₂O
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Write a balanced equation for the incomplete combustion of:
pentene + oxygen ------> carbon monoxide + water
C₅H₁₀ + 5 O₂ ------> 5CO + 5H₂O
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What are the uses of methanol
1) good FUEL
2) good SOLVENT
3) starter chemical for other carbon containing compounds
4) makes up 95% of methylated spirits (other 5% H₂O)
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What is the production of methanol
The Motunui synthetic Fuels plant in Taranaki is responsible for converting natural gas (METHANE) into METHANOL. This is known as 'SYNTHETIC FUEL'. This involves 3 steps.
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What is the first step in the production of methanol
1) SOURCE THE METHANE:
The plant takes methane from GAS FIELDS.`
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What is the second step in the production of methanol
2) THE REFORMING PROCESS (reform methane into something else):
The methane is converted into "synthesis gas' which is CO & H₂. It requires STEAM and HIGH TEMP (500°C+)/HIGH PRESSURE (40atm)/Nickel CATALYST
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What is the formula for the second step in the production of methanol
(800°C high pressure nickel)
CH₄ + H₂O --------------------------------------------> CO + 3H₂
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What is the third step in the production of methanol
3) SYNTHASIS (MAKING THE METHANOL):
The synthesis gas is then passed over another catalyst (Cu + Zn) at a lower temp (250°C). This makes CH₃OH. It produces heat.
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What is the formula for the third step in the production of methanol
250°C CuZn catalyst
CO + 2H₂ ---------------------------------------> CH₃OH
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Products of combustion:
Environmental effects of CO₂ and H₂O:
CO₂ gas acts as a blanket over the earth, trapping heat (infrared radiation) in earth's atmosphere instead of letting it out into space. As the heat is trapped, it prevents earth from cooling & raises global temperatures. Water vapor and CO₂ are both greenhouse gases, and trap the infrared radiation in earth's atmosphere. Water vapor makes the atmosphere more humid, and amplifies the warming from CO₂.
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Products of combustion:
Environmental effects of CO (carbon monoxide) and C:
Carbon monoxides, when emitted into the atmosphere, effects the amount of greenhouse gases, which impacts land and sea temperature. It also contributes to increased storm activity and other extreme weather events. CO reacts with hydroxyl (OH) in the atmosphere, OH helps to reduce the lifetime of some strong greenhouse gases, so CO is preventing it from doing so. Soot (carbon, C) causes haze when sunlight interacts with small particles in the atmosphere. It also increases the acidity of lakes and rivers.
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Products of combustion:
Effects on human health from CO and C:
Carbon monoxide binds to red blood cells, reducing the ability of blood to carry oxygen, therefore interfering with the amount of oxygen carried to the organs. This causes fatigue, headaches, confusion & dizziness, because of less oxygen being delivered to the brain. Soot enters the body through inhalation, ingestion or via the skin and eyes. This can then cause breathing issues, bronchitis, heart disease & cancer. it affects infants, the elderly & those with existing breathing problems the most.
