Unit 4 Organic Chem Flashcards
1
Q
What’s meant by the term hydrocarbon
A
Compound consisting of carbon and hydrogen atoms only
2
Q
What’s meant by a saturated compound
A
Contains noC=C bond
3
Q
What’s meant by an unsaturated compound
A
Contains a c=c bond
4
Q
What’s meant by the term aliphatic compound
A
Compound where the carbon atoms are joined together to form a straight chain eg butane
5
Q
What’s meant by the term alicyclic compound
A
Compound where the carbon atoms are joined together in a ring structure, eg cyclobutane
6
Q
What’s meant by aromatic compound
A
Compound which contains a benzene ring, ie toluene
7
Q
What’s meant by the term functional group
A
Part of the organic molecule responsible for its chemical reactions
8
Q
formula,prefix, suffix and eg of ALKANE(functional groups alkane)
A
Formula C-C
Suffix - ane
Eg- propane
9
Q
Functional group, formula,prefix, suffix and eg of ALKENE
A
Formula C=C
Suffix - ene
Eg- prop-1-ene
10
Q
Functional group, formula,prefix, suffix and eg of Haloalkane
A
Formula- F, Cl, Br, I
Prefix - Fluo, chloro, Bromo, Iodo
Suffix - ane
Eg- fluoropropane, bromopropane, chloropropane, iodopropane
11
Q
Functional group, formula,prefix, suffix and eg of alcohol
A
Formula - coh
Prefix- hydroxy
Suffix- ol
Oh on end chain so C1
12
Q
Functional group, formula,prefix, suffix and eg aldehyde
A
Formula - CHO
Suffix - anal
Eg - propanal, has double bond with oxygen, c1 and then H
13
Q
Functional group, formula,prefix, suffix and eg of KETONE
A
Formula - C(C=O)C
Suffix- one
Eg- propan-2-one
Has double bond with xgyen in middle so like c2 or c3
14
Q
Functional group, formula,prefix, suffix and eg of carboxylic acid
A
Formula- COOH
Suffix - oic acid
Eg- propanaoic acid
O
II
C
/
HO
15
Q
What’s meant by the term General formula
A
Simplest algebraic formula of a member of a homologous series
16
Q
What’s meant by the term homologous series
A
same functional group Each successive member differing by CH2
17
Q
State the hydrocarbons, the formula, Stem Name, alkyl group, and formula of alkyl group
A
Formula|Stemname|Akylgrp|Frmlalkylgrp
Methane -CH4. Meth. Methyl. CH3
Ethane - C2H6. Eth. Ethyl. C2H5
propane- C3H8. Prop. Propyl. C3H7
Butane - C4H10. But. Butyl. C4H9
pentane - C5H12. Pent. Pentyl. C5H11
Hexane - C6H14. Hex. Hexyl. C6H13
Heptane - C7H16. Hept. Heptyl. C7H15
Octane - C8H18. Oct. Octyl. C8H17
Nonane - C9H20. Non. Nonyl. C9H19
Decane- C10H22. Dec. Decyl. C10H21
18
Q
What’s meant by the displayed formula
A
The formula showing the relative positioning of all the atoms in a molecule and the bonds between them
19
Q
State the maximum covalent bonds formed in c, h, o , n
A
C-4.
H-1
O-2
N-3
20
Q
state what’s meant by structural isomerism
A
compounds with the same molecular formula but different structural formula
21
Q
state the 3 types of structural isomers that exist
A
chain isomerism, positional isomers, functional group isomerism
22
Q
state what’s meant by chain isomerism
A
when the carbon chains can be either branched or unbranched
23
Q
state what’s meant by positional isomerism
A
functional group or branch can be at a different position
24
Q
what’s meant by functional group isomerism
A
functional groups can be different
24
State the general formula of alkanes.
CnH2n+2
25
Explain why all alkanes are non-polar molecules.
only contain C-H bonds
there's no Significant difference between the electronegativities of carbon and hydrogen
26
Give two reasons why alkanes are generally unreactive.
molecules are non polar (no overall dipoles)
C-C and C-H bonds have high bond enthalpies
27
State a use for alkanes
used as fuels
28
This question is about the shape, structure and bond rotation in alkanes. Explain the shape around carbon atoms in an alkane
there are 4 bonding pairs and 0 lone pairs around each carbon atom.
All electron pairs repel
molecule forms a tetrahedral shape around each carbon atom
bond angles around each carbon will be 109.5
alkanes are saturated molecules that contain sigma bonds only.
29
Explain what is meant by a sigma bond.
caused by the end on end overlap of bonding orbitals directly between atoms.
all bonds can rotate in an alkane
30
Describe and explain the change in boiling and melting points with carbon chain length.
as chain length and number of carbon atoms increases, Boling and melting point increases
larger molecules have more points of surface contact between molecules
strength of induced dipole-dipole interactions between molecules increases, which requires more energy to overcome
31
Describe and explain the change in boiling and melting points with number of branches.
the more branches in an isomer molecule, the lower the boiling point.
there are less points of surface contact between molecules
there are weaker induced dipole-dipole interactions between molecules which requires less energy to overcome
32
Explain what is meant by complete combustion.
burning of a substance in excess supply of oxygen
33
Write an equation to show the complete combustion of methane
CH4 +2 O2 --> CO2 + H2O
34
Explain what is meant by incomplete combustion.
burning of a substance in limited supply of oxygen.
35
Write an equation to show the incomplete combustion of methane to produce carbon monoxide and water only
CH4 +1.5 O2 --> CO + 2 H2O
36
Write an equation to show the incomplete combustion of methane to produce carbon particulates and water only
CH4 + O2 --> C + 2 H2O
37
Explain why carbon monoxide is hazardous
carbon monoxide is toxic
38
Explain why branched chained alkanes are preferred to be used as fuels.
they have more efficient combustion
39
State and explain the polarity of haloalkanes
They're polar molecules due to the polar carbon- hydrogen bonds
halogen atom is more electronegative than the carbon atom
Classified as either primary secondary or tertiary haloalkanes
40
Explain why 1- bromopropane has a higher boiling point than propane
Propane has induced dipole dipole interactions between the molecules but one bromopropane also has permanent dipole dipole interactions which are stronger and require more energy to overcome
41
Explain why haloalkanes are reactive
Partially positive carbon can react with nucleophiles
42
Define by what's meant nucleophiles and give egs
electron pair donor, eg :CN, :OH, :NH3
43
Explain what's meant by alkali hydrolysis
haloalkanes react with NaOH or KOH to form alcohols
44
State the conditions needed for alkali hydrolysis
warm aqueous NaOH or KOH and reflux
45
Explain how you can set up an experiment to monitor the rate of hydrolysis
Add water and silver nitrate AgNO3 solution I the beaker with the haloalkane
Silver ions react with halides as soon as they form - silver halide precipitate formed
Time how long it takes for the precipitates to form
46
State and explain the trend in hydrolysis from fluoroalkanes to iodoalkanes
rate of hydrolysis increases down group 7
carbon halogen bond becomes weaker
47
Explain the difference in the rate of hydrolysis between 2-iodobutane ans 2-chloropropane
Rate is slower with chloroalkanes
C-l bond is weaker than C-Cl bond
48
What's meant by heterolytic fission
Covalent bond breaks and both electrons go to the same atom forming 2 ions
49
What's meant by curly arrows
Shows the movement of an electron pair
50
What's meant by homolytic fission
Covalent bond breaks and one electron goes to each atom forming 2 radicals
51
State what's meant by radicals
Highly reactive species with an unpaired electron
52
What's meant by a mechanism
Step by step sequence of a reaction at which an overall reaction occurs
53
What's meant by a nucleophile and give egs
Electron pair donor
Cn oh and nh3
54
Describe the properties of a nucleo0hiles in terms of attraction and electron density
Nucleophiles are described as a region of higher electron density and are attracted to regions of low electron density
55
What's meant by electrophile and give eg
Electron pair acceptor eg Br2 Cl2 I2 HCl
56
Describe the properties of a electrophile in terms of attraction and electron density
Electrophiles are described as a region of low density and are attracted to regions of high electron density
57
State 5 examples of mechanisms in organic chemistry and include their relative atom economies
Free radical substitution
Nucleophilic substitution
Electrophilic substitution
Nucleophilic addition
Electrophilic addition
58
What's meant by halogenation
organic compounds react with halogens to form haloalkanes
59
State the reaction conditions for halogenation
Uv and high temperature
60
State 2 limitations of radical subsitution
Further substitution
Substitution occurs at different positions on chain
(resulting in isomers being formed)
61
State two hazards of UV radiation.
Sun burn and skin cancer
62
Explain how life on Earth benefits from the presence of an ozone layer in terms of UV radiation.
Ozone absorbs UV radiation.
UV at Earth's surface is reduced.
63
What is a CFC?
Compounds that contain chlorine, fluorine, and carbon atoms only - all hydrogens replaced.
64
State four properties of CFC's.
Stable, volatile, non-flammable, and non-toxic.
65
Give three previous uses of CFC's.
Aerosol cans, dry cleaning, air conditioning, and fridges.
66
How are chlorine radicals generated from CFC's?
Uv
CF2Cl2 --> CF2Cl ● (g) + Cl●(g)
C-cl
67
How do chlorine radicals catalyse the breakdown of the ozone layer?
Cl ●(g) + O3(g) ---> O2 + ClO● (g)
ClO (g) + O(g) ---> O(g) --> O2+Cl●
68
Why are HCFCs preferred over CFCs?
HCFCs are broken down in the atmosphere more quickly (in 10-20 hours rather than 90).
69
Why are HFCs preferred over CFCs?
HFCs are broken down in the atmosphere too; they don't contain Cl and so don't affect the ozone layer.
70
What is a disadvantage of using HFCs and HCFCs?
They are greenhouse gases.
71
What are three alternatives to CFCs?
1. Aerosols with pump sprays/nitrogen propellants used instead.
2. Fridges and freezers use ammonia as the coolant gas.
3. CO2 used to make expanded polymers.
72
State 2 sources of nitrogen oxides in the stratosphere
Thunderstorm and aircraft engines.
(car engies maybe)
73
State the general formula of alkenes and its functional group.
CnH2n C=C
74
Explain why alkenes are more reactive than alkanes.
Alkenes are more reactive than alkanes undergoing addition reactions. They contain a C=C bond which contains a weak pi bond
Pi bonds are weaker than sigma bonds
75
Describe and explain the shape of an alkene around the C=C atoms
trignol planar shape and 120* bond angle around each c atom in the C=C bond.
4 Bonded pairs around the c atom.
there are 3 bonding regions
all electrons repel, to get as far apart as possible
76
define the term pi bond
sideways overlap of P orbitals to give a pi bond above and below
77
define whats meant by a stereoisomer
compounds with the same structural formula but a different arrangements of atoms in space
78
whats meant by an e isomer
when both groups are at either side
79
state by whats meant by a z isomer
when both groups are at the same side
80
state 2 requirements for molecule to exhibit e/z isomerism
contain a c=c bond which doesnt rotate and restricts rotation
each carbon atom of the double bonds attached to 2 different groups
81
How is priority, E-isomers and Z-isomers determined using Cahn Ingold prelog priority rules
Atom with the higher atomic number on each carbon is given the higher priority
E isomer- highest priority groups are on the opposite sides of the c=c bond
z isomer- highest priority groups are on the same side of the c=c bond
82
Explain why alkenes are more reactive than alkanes.
they contain a c=c bond which contains a weak pi bond
pie bonds are weaker than sigma bonds
83
State what is meant by an addition reaction
reaction where 2 or more molecules combine together to make a larger molecule
84
What is the % atom economy for an addition reaction
100
85
Explain what is meant by “halogenation
alkenes react with halogens or hydrogen halides to form haloalkanes
86
State the conditions required to go from an alkene to dihaloalkane.
20*C
87
State the mechanism for halogenation of alkenes.
Electrophilic addition
88
A student has two test tubes, A and B. One contains an alkene. One contains an alkane. Describe a test, including observations for each, that the student could do determine which is the alkene and which is the alkane.
add bromine water to a solution and shake
contains double bond (unsaturated)- orange to colourless
bromine is added across the double bond
contains no double bond (saturated) no visible change
89
Explain what is meant by “hydrogenation
alkenes react with hydrogen to form alkanes
90
State the conditions required to go from an alkene to alkane hydrogenation
Ni and 150*C
91
Explain what is meant by “hydration”.State the conditions required to go from an alkene to an alcoho
Alkenes react with steam to form alcohols
H3PO4 catalyst, 60-70 atm and 300*C
92
Give the systematic name for the allyl bromide
3-bromopropene
93
whats the max number of stereoisomers we can have
2n where n is the number of chiral centres.
94
what are chiral carbon atoms
have 4 different groups
95
State the mechanism for the halogenation of alkenes
electrophilic additon
96
State Markovnikov’s rule.
major product forms from more stable carbocation intermediate
major product formed from carbocation bonded to more alkyl groups
97
State the three types of carbocations in order of stability.
primary carbocation, secondary and tertiary num of alkyl groups increases
98
explain the potential danger of incomplete combustion
CO is toxic
99
explain why free radical substitution is likely to produce a mixture of organic products 1 mark
substitution can replace any H atom
100
whats the general formula for cycloalkanes
CnH2n
101
write eq to show how nitrogen monoxide catalyses the breakdown of ozone
NO + 03 ---> N02 + 02
NO2 + 0 ----> NO + O2
102
How could a student obtain a sample of mg phosphate after reacting magnesiums with phosphoric acid
filter to obtain solid precipitate. dry
104
hows the concentration of ozone maintained in the ozone layer
O 3 ⇌ O 2 + O
105
write eq Cf2CL2 produces radicals which catalyse the breakdown of ozone
CF2Cl2---> Cl+ CF2Cl
C l + O3 ---> ClO + O2
ClO+ O ---> Cl + O2
ClO + O3 ---> Cl + O2
106
How does NO catalyse the breakdown of ozone
N O + O3 --> NO2 + O2
NO2 + O --> NO• + O2
107
what are nucleophilic substitution reactions
involves swapping of nucleophiles and halogen atoms
atom economy always less than 100
reaction to synthesise alcohols from haloalkanes.
so haloalkane to alchol
condition warm aqeous naoh or koh
108
state 2 sources of nitrogen oxides in the stratosphere
thunderstorms and aircrafts
109
state 3 properties that make cfs suitable for use as an aerosol
non flammable,volatile, non toxic
110
when carrying out hydrolysis experiment, how could you modify it so it could be completed in less time?
heat the test tubes in a waterbath
111
state and explain how the halogen in the haloalkane affects the rate of hydrolysis 3 marks
the weaker the bond the faster the reaction
C-F bond is hydrolysed slowest
c-i bond hydrlysed faster than c-br
112
what method and observation would allow student to compare the rates of hydrolysis halogens.
time for precipitate to appear
113
explain why 1-iodopentane was found to react faster than 1-bromopentane. explain why
c-1 bonds weaker than c-br bonds
so require less energy to overcome
carbon to halogen halogen bond breaks
114
describe the reactivity of alkenes
pie bonds are weaker than sigma bonds
pie bonds can break and electrons can be donated to form a bond
involved in reactions called addition reactions
addition reactions have 100% atom economy
115
how can we produce haloalkanes and dihaloalkanes from an alkene
by reacting it with a halogen- 20* temp forms dihaloalkane.
hydrogen halide- 20* and forms haloalkane
116
describe what happens in electrophilic additon
synthesisng dihaloalkanes/haloalkanes from alcohol
2. 1. 2 electrons from C=C attack the partially positive X atom creating a new bond
2. x-y bond breaks by heterolytic fission
3. positively charged carbocation intermediate is formed
4. :Y- acts as a nucleophile attacking the positively charged carbocation intermediate donating its lone pair of electrons forming a new bond
117
In a reaction between an unsymmetrical alkene and a hydrogen halide/ steam explain why one organic product is formed in a much greater quantitiy than the other product
Major product formed from more stable carbo cation intermediate
Major carbocation bonded to more alkyl groups
118
whats a monomer and a polymer
monomer- single repeating unit
polymer- made up of long repeating units of monomers
119
Reactivity of polymers
Alkenes are unsaturated compounds
Polymers are saturated compounds
Polymers are chemically inert and are not biodegradable
120
Disposing of waste adv and disav
polymers are unreactive and so arent biodegradeable
adv- long lasting and reuseable
disadv- difficult to dispose
121
When can we Burying waste plastic
Waste plastic can be placed in landfill when:
- Too difficult to separate from other waste.
- Not in sufficient quantities to make separation financially worthwhile. v
- Too difficult technically to recycle. v
122
Recycling plastics
We can sort plastics into different types.
Polypropene can be melted and remoulded.
Others can be cracked into monomers which can be used as organic feedstock to make more plastics/ chemicals. v
Overall process involves sorting and processing. v
123
Burning waste plastic
advCombust to generate electricity
diasv CO2 released which is a greenhouse gas. causing global warming
NaHCO,, neutralises and removes HCl.
Example: poly(chloroethene)
Combustion: C2H,Cl + 2.502 → 2CO2 + HCI + H20. V
Neutralisation of toxic gas: HCl + NaHCO: → NaCl + H,0 + COz. V
chloroethene
124
Biodegradable/ Photodegradable polymers
Made from materials such as starch and the hydrocarbon isoprene.
Benefits:
- Renewable raw materials will not run out. v
- Carbon neutral for plant-based polymers. V
- Plant-based polymers save energy. V
125
what are cis and trans isomers
E/Z isomerism in which 2 substituent groups attached to each carbon atom of the C=C group are the same
TRANS ISOMER- both carbon atoms on a double bond have an identical group (H) which are on the opposite sides of the double bond.
CIS- both carbons on the double bond have an identical group (HYDROGEN )these are on the same side of the double bond.
126
Suggest why 2-methylbut-2-ene is less soluble in water than C5H120
doesnt form hydrogen bonds with water
Doesnt contain OH groups
127
Outline how a catalyst increases the rate of a chemical reaction
Lowers the activation energy
So that a greater proportion of molecules exceed the activation energy
128
MOLECULAR FORMULA EG
CxHx
129
why does pent1ene not show stereoisomerism
One of the carbons of the C=C has two of
the same groups attached
(stereoisomers have 2 didf groups attached to esch csrbom£
130
outline 2 ways that waste hydrocarbon polymers can be processed usefully rather than disposed of in landfill sites
combustion to generate electricity
recycled
131
why are alcohols added to petrol mixtures and why can they be combusted
to prevent incomplete combustion as they contain an internal supply of oxygen in the form of an OH group
they are good fuels with high enthalpies of combustion
132
in Alcohols substitution reactions
synthesis of haloalkanes from alcohols
reaction conditions and reagents NaBR and H2SO4
133
Properties of alcohols
Alcohols are polar molecules ✓
This is due to the electronegative hydroxyl groups, which pulls the electrons in the C-OH bond away from the carbon atom.Hydroxyl group – R-OH ✓
134
✓
Boiling points of alcohols
Alcohols have higher boiling points compared to alkanes ✓
Alcohols are less volatile than alkanes of similar carbon atoms ✓
135
Hydrogen bonding in alcohols
Alcohols have hydrogen bonding between molecules ✓
Alkanes have induced dipole-dipole interactions between molecules ✓
Hydrogen bonding is stronger and requires more energy to overcome ✓
136
Solubility of alcohols
Alcohols with short carbon chains are soluble in water ✓
Alcohols and water molecules make hydrogen bonds with each other ✓
Alcohols make neutral solutions ✓
If there are more OH groups, there are more hydrogen bonds and so the alcohol
will be more soluble ✓
137
Solubility of alcohols and chain length
The greater the carbon chain length, the less soluble the alcohol is in water ✓
There are stronger induced dipole-dipole interactions in longer carbon chains ✓
Which break up hydrogen bonds between molecules ✓
138
How can we remove hcl
NaHCO,, neutralises and removes HCl
poly(chloroethene)
Combustion: C2H,Cl + 2.502 → 2CO2 + HCI + H20. V
Neutralisation of toxic gas: HCl + NaHCO: → NaCl + H,0 + COz. V
chloroethene
139
Describe how hcl is removed from the waste gasses produced 1 mark
HCL gas is passed through alkali
140
Sugges adv of adding cyclohexane to Hexane in petrol
Will burn more efficiently
141
Whats the general formula of alkyl groups
CnH2n+1
142
whys butan-2-ol classed as a secondary alcohol
The –OH group is attached to a carbon
that is attached to two C atoms
143
elimination reactions
synthesis of alkene from ALCOHOL
requires h3po4
forms alkene and water
144
Elimination of h20 from pentan-2-ol forms a mixture of organic compounds. explain how the reaction leads to different isomers
the elimination can produce a double
bond in either the 1- or the 2- position
(through combination of the hydroxyl
group with a hydrogen from either the
1st or the 3rd carbon)
this leads to the formation of structural
isomers (pent-1-ene and pent-2-ene)
pent-2-ene exhibits stereoisomerism
E/Z isomerism / cis–trans isomerism
because it has two different groups
attached to each carbon atom
there are two possible isomers of
pent-2-ene and three in total.
145
Oxidation reactions alcohols, what happens when you heat a primary alcohol with the reagents with distillation apparatus?
Heating a primary alcohol with K2Cr2O7 and H2SO4 with distillation apparatus produces an aldehyde ✓
146
Oxidation reactions alcohols, what happens when you heat a primary alcohol with the excess reagents under reflux?
Heating a primary alcohol with excess oxidising agent and H2SO4 under reflux produces a carboxylic acid ✓
147
Oxidation reactions alcohols, what happens when you heat an aldehyde with the reagents with reflux apparatus?
Heating an aldehyde with potassium dichromate(VI) solution and H2SO4 with reflux apparatus produces a carboxylic acid and no water
148
Oxidation reactions alcohols, what happens when you heat a secondary alcohol with excess reagents under reflux?
Heating a secondary alcohol with excess oxidising agent and H2SO4 under reflux produces a ketone
149
what happens when tertiary alcohols are oxidised
tertiary alcohols cant be oxidised. no reaction
150
Testing for alcohols
Tertiary alcohols don’t react with acidified potassium dichromate(VI) ✓
Can be used to test between primary and secondary alcohols against tertiary alcohols ✓
Add few drops of potassium dichromate(VI) and a few drops of
concentrated H2SO4 ✓
Colour change from orange to green indicates presence of primary and secondary alcohols ✓
No visible change for tertiary alcohols
151
whats Distillation
separation technique
Used to separate liquids with different boiling points and
to prevent further reaction
152
whats Reflux
Used to react volatile substances together to prevent substances from escaping. ✓
153
whats Infrared Spectroscopy
Beam of infrared radiation is passed through a sample of a chemical
Bonds between different atoms absorb different frequencies of IR radiation ✓
IR radiation causes covalent bonds to vibrate more ✓
IR radiation that is not absorbed is detected by a detector ✓
154
how do we Produce a spectrum
IR radiation -----> detector
IR radiation -> sample->detector
155
Alcohols, phenols wavenumber, characteristic and bond.
3200-3600cm-1
Peak around 3200cm-
O-H
156
Carboxylic acids wavenumber, characteristic and bond.
2500-3300
Broad peak centred
around 3000cm-
O-H
157
Aldehydes, ketones, carboxylic
acids, esters, amides bond, wavenumber and characteristic.
1630-1820
Sharp peak (pointy) at
about 1700cm-1
C=O
158
Exlain Why a molecule with OH has a higher boiling point than a molecule with NH3
O atom is more electronegative that N atom.
O atom has more lone pairs than the N atom.
Stronger hydrogen bonding between molecules.
159
How do we purify a liquid
Purification: Redistillation
Re-distil to get purer product. Collect the fraction having the boiling point of the pure compound ✓
Separating funnel
Products of a reaction and water is added to a separating funnel and the funnel is shaken and then allowed to settle. ✓
Less dense organic layer settles at the top. ✓
Water-soluble impurities dissolve in the lower aqueous layer ✓
Stopper is turned, aqueous layer is run off.
Drying agents
Anhydrous MgSO4 or CaCl2 is used as a drying agent ✓
Drying agent can be removed by filtration once it settles to the bottom ✓
Vacuum Filtration
Solids can be filtered under vacuum ✓
160
How does IR Spectroscopy cause Global warming
Green houses gases in the troposphere absorb re-emitted IR radiation from the earth ✓
Some of this radiation is re-emitted in all directions, including back to the earth ✓
Greenhouse gases: water vapour (O-H), carbon dioxide (C=O) and methane (C-H)
161
Uses of IR spectroscopy
Modern breathalysers
Use IR spectroscopy to look for the presence of ethanol in the driver’s breath ✓
Detects O-H bonds ✓
162
Monitoring gases causing air pollution
Monitor concentrations of polluting gases in the atmosphere ✓
Examples include CO and NO – Intensity of the peaks corresponding to CO/ NO bonds
studied
163
Mass Spectrometry Uses:
1. Monitor breathing of patients under anaesthetic ✓
2. Testing for drug use in athletes/ horses ✓
3. Analysing molecules in space ✓
4. Testing for toxic chemicals that may have contaminated marine life
164
Interpreting mass spectre and fragments
1. Molecular Ion peak, M+ (g) peak
Molecular Ion peak, M+ g) peak – Peak furthest to the right ✓
The m/z of this peak corresponds to the Mr of the unknown molecule ✓
M+1 peak: Molecule could contain an atom of C13 and so has an extra mass value ✓
2. Fragments
Molecular ions can break up into fragments ✓
Fragments appear on a mass spectrum – fragmentation pattern. ✓
We can use this to identify molecules and their structure.
165
What does the abundance of peaks depend on
How many times these fragments appear in a molecule
How stable the fragment is (think back to the stability of carbocation intermediates)
