B3 Organic Chemistry I Flashcards
(136 cards)
1
Q
How are two numbers seperated in organic nomenclature
A
Comma
2
Q
How are numbers and letters seperated in organic nomenclature
A
Dash
3
Q
Which carbon number does the highest priority functional group get
A
The lowest carbon number
4
Q
Where there are the same priority groups, which group gets the lowest carbon number
A
First group alphabetically
5
Q
General formula of alkyl groups
A
6
Q
Six carbon prefix
A
Hex
7
Q
Seven carbon prefix
A
Hept
8
Q
Nine carbon prefix
A
Non
9
Q
Ten carbon prefix
A
Dec
10
Q
Define empirical formula
A
The simplest whole number ratio of atoms of each element present in a compound
11
Q
Define molecular formula
A
The total number of atoms of each element present in a molecule
12
Q
Define homologous series
A
- A series of organic compounds with the same functional group
- But with each successive member differing by CH2
13
Q
What is an aliphatic compound
A
- Contains hydrogen and carbon atoms
- Joined in a straight chain, branched chain, or non-aromatic ring
14
Q
What is an alicyclic compound
A
- An aliphatic compound
- Arragned in non-aromatic rings
- With or without side chains, but no benzene ring
15
Q
What is an aromatic compound
A
Contains a benzene ring
16
Q
How are benzene rings drawn
A
17
Q
Relationship between compounds being alicyclic and aliphatic
A
- All alicyclic are aliphatic
- Not all aliphatic are alicyclic
18
Q
What is a saturated compound
A
Contain single carbon-carbon bonds only
19
Q
What is an unsaturated compound
A
Contain multiple carbon-carbon bonds
20
Q
Define structural isomers
A
Compounds with the same molecular formula, but different structural formulae
21
Q
Define homolytic fission
A
Each bonding atom recieves one electron from the bonded pair, forming two radicals
22
Q
Define heterolytic fission
A
One bonding atom recieves both electrons from the bonded pair, forming an ion
23
Q
Define radical
A
A species with an unpaired electron
24
Q
Define Curly Arrow
A
The movement of a pair of electrons, showing either heterolytic fission, or the formation of a covalent bond
25
What is the only type of covalent bond present in alkanes
Sigma bonds
26
Why do alkanes have a low reactivity
* High bond enthalpy of the C-H and C-C bonds
* Low bond polatiry of the C-H and C-C bonds
27
General formula of alkanes
28
General formula of cyclic alkanes
29
What bonds will be present in a single covalent bond
A sigma bond
30
What bonds will be present in a double covalent bond
One sigma bond, one pi bond
31
Ways to comapre sigma and pi bonds
* Orbital overlap
* Bond enthalpy
* Electron density
* Rotation
32
What bonds will be present in a triple covalent bond
One sigma bond, two pi bonds
33
Sigma vs Pi: Orbital overlap
* Orbitals overlap directly between bonding atoms in sigma
* Sideways overlap of adjacent p-orbitals above and below the bonding atoms in pi
34
Sigma vs Pi: Electron density
Sigma have a much higher electron density than pi bonds
35
Sigma vs Pi: Rotation
* Sigma have free rotation
* Pi have restricted roation
36
Sigma vs Pi: Bond enthalpy
* Sigma have a higher bond enthlapy so are stronger
* Pi have a lower bond enthalpy so are weaker
* More energy is requred to break sigma bond than pi bond
37
Explain why a longer carbon chain alkane has a higher boiling boint than a shorter carbon chain alkane
* Longer carbon chain means larger surface area for contact of London forces acting between molecules
* London forces therefore stronger
* More energy required to break London forces
38
Explain why the more branched an alkane's carbon chain is, the lower it's boiling point
* More branched carbon chain means smaller surface area for contact of London forces acting between molecules
* Weaker London forces
* Less energy requreid to break London forces
39
Word equation for alkane complete combustion
40
Word equation for alkane incomplete combustion
Produces Carbon Monoxide which is toxic
41
Why is alkane incomplete combustion hazardous
Produces carbon monoxide which is toxic
42
What condition is required for Free Radical Substitution and why
* UV Light
* Provides energy to break covalent bond (homolytic fission)
43
Free Radical Substitution: initation step for chlorine and butane
44
Free Radical Substitution: propagation steps for chlorine and butane
45
Free Radical Substitution: Termination steps for chlorine and butane
46
Why is Free Radical Substitution limiting to produce a desired product
* Substitution can replace any hydrogen atom in any position along carbon chain
* Further substitution can occur
* There is more than one termination step, so more than one termination products
47
General formula for alkenes
48
Functional group of alkenes
C=C bond
49
Why are alkenes very reactive
The pi bond in the C=C bond has a low bond enthalpy
50
Draw a labelled diagram of a pi bond
51
Define stereoisomers
Compounds with the same structural formula, but with a different arrangement in space
52
When can E/Z isomerism occur in alkenes
When each carbon involved in the C=C bond, has two different groups bonded to it
53
When would an alkene not have steroisomers
If one/both the carbons involved in the C=C bond has two of the same groups attached
54
In stereoisomerism, how do you decide on priority groups
Group with highest atomic number
55
How to explain if an alkene is an E isomer
* X is priority group over Y on left hand side carbon involved in the C=C bond
* A is priority group over B on the right hand side carbon involved in the C=C bond
* Prioritry groups are on opposite sides
56
How to explain if an alkene is a Z isomer
* X is priority group over Y on the left hand side carbon involved in the C=C bond
* A is priority group over B on the right hand side carbon involved in the C=C bond
* Priority groups are on the same side
57
When can Z-isomers be reffered to as cis isomers
As long as there is a hydrogen on each carbon atom of the C=C bond
58
When can E isomers be reffered to as trans isomers
As long as there is a hydrogen on each carbon atom of the C=C bond
59
Define electrophile
An electron pair acceptor
60
What type of reaction is alkene to alkane
Electrophillic addition
61
Conditions and reagents for alkene to alkane
* Hydrogen
* Nickel Catalyst
62
Displayed formula equation for ethene to ethane
63
Type of reaction for alkene to halogenoalkane
Electrophillic addition
64
How are alkenes tested for
* Add bromine water
* Will be decolourised
65
Mechanism for bromine + ethene
66
Reagents and conditions to turn alkene to alcohol
* Phosphoric acid catalyst
* Steam
67
Displayed formula equation for alkene to alcohol
68
What is the most stable carbocation
Tertiary
69
What is the least stable carbocation
Primary
70
Primary Carbocation
71
Secondary carbocation
72
Tertiary carbocation
73
In alkene reactions with hydrogen halides, to which carbocation will the hydrogen to go
The least stable
74
In alkene reactions with hydrogen halides, to which carbocation will the nucleophile (halogen) to go
The most stable carbocation
75
Draw the mechanism for an alkene reaction with hydrogen halide, including both major and minor products
76
Explain the three ways in which addition polymers can be destoryed
* Combustion - releases lots of energy for electricity
* Organic feedstock for production of other polymers
* Recycling
77
Displayed formula equation for addition polymerisation of ethene
78
Why is combustion of addition polymers an issue
* Results in formation of HCl and CO
* Which are toxic
79
How can HCl be removed as a product from combusting addition polymers
Passing it through an alkali
80
Why are biodegradeable and photodegradable polymers more beneficial to the enviroment
* As they don't need to be incinerates
* So there is no formation of HCl and CO
* Which are toxic
81
What is the functional group of the alcohol homologous series
-OH (hydroxyl)
82
Alcohol general formula
83
Primary alcohol
84
Secondary alcohol
85
Tertiary alcohol
86
Describing primary alcohol
If the carbon the -OH group is bonded to has two hydrogens bonded to it
87
Describing a secondary alcohol
If the carbon the -OH is bonded to has one hydrogen bonded to it
88
Describing tertiary alcohol
If the carbon the -OH group is bonded to has no hydrogens bonded to it
89
Why are alcohols soluble
* They contain an -OH (hydroxyl) group
* The -OH group can form hydrogen bonds with the water
90
Why do alcohols have higher boiling points than other homologous series
* They contain an -OH (hydroxyl) group
* The -OH group can form hydrogen bonds with other molecules
* More energy is needed to break the hydrogen bonds than the London Forces in other homologous series
91
Conditions, reagents and observations for primary alcohol oxidation to aldehydes
* Potassium dichromate
* Sulfuric acid
* Heat and distill
* Potassium dichromate will turn orange to green
92
Conditions, reagents and observations for primary alcohol oxidation to carboxylic acid
* Add pottassium dichromate
* Sulfuric Acid
* Heat under reflux
* Potassium dichromate will turn orange to green
93
Structural and displayed formula equation for primary alcohol oxidation to aldehyde
94
Suffix for aldehyde
-anal
95
Structural and displayed formula equation for primary alcohol oxidation to carboxylic acid
96
Conditions, observations and reagents for secondary alcohol oxidation to ketone
* Potassium dichormate
* Sulfuric Acid
* Heat under reflux
* Potassium dichromate will turn orange to green
97
C=O group name
Carbonyl
98
Ketone suffix
-one
99
Strucutral and displayed formula for alcohol to ketone
100
What is the way in which tertiary alcohols must be oxidised
Combustion
101
Word equation alcohol complete combustion
102
Word equation alcohol incomplete combustion
103
Why is incomplete combustion of alcohols hazardous
Produces carbon monoxide which is toxic
104
Reagents and conditions for alcohols to alkenes
* Phosphoric acid
* Heat
105
Why is there only one possible product of primary alcohol elimination to alkene
The C=C bond can only from from one carbon
106
Displayed formula equation primary alcohol elimination to alkene
107
Why will secondary and tertiary alcohols be able to produce multiple products, and what will they be
* The C=C bond can form from two carbons
* They could have E/Z isomerism
108
Conditions and reagents for alcohol to haloalkane
* Sodium halide
* Sulfuric acid
109
What type of reaction is alcohol to haloalkane
Nucleophillic Substitution
110
Displayed formula equation for alcohol to haloalkane
111
# ```
Type of reaction from haloalkane to alcohol
Nucleophillic substitution
112
Conditions and reagents for haloalkane to alcohol
* Warm NaOH
* Acid catalyst (sulfuric acid)
* Heat under reflux
113
Mechanism for nucleophillic substiution of haloalkane to alcohol
114
Define nucleophille
An electron pair donor
115
How to measure reactivity of haloalkanes experementally, and result
* Add AgNO3 and ethanol
* The iodo-compound will take the shortest time to form a precipitate
116
Describe and explain the reactivity of the haloalkanes
* C-Cl bond is strongest, then C-Br bond, then C-I bond is weakest
* C-Cl bond has higher bond enthalpy, then C-Br bond, then C-I bond has lowest
* More energy is required to break the C-Cl bond than the C-Br bond
* More energy is required to break the C-Br bond than the C-I bond
117
What is a CFC
A molecule containing, carbon, flourine and chlorine
118
What are the primary properties of CFCs
* Non-toxic
* Volatile
* Low reactivity
119
What is the function of the ozone layer, and what equation shows how ozone's concentration is maintained
Absorbs UV radiation, so that UV levels at the Earth's surface are reduced
120
What happens to CFCs in the presence of UV radiation
They can produce radicals
121
What acts as a catalyst in the breakdown of the ozone layer
Chlorine radicals and nitrogen oxide radicals
122
Initiation stage for ozone breakdown by CFC's
123
Propogation stages for ozone breakdown by CFC's
124
Overall equation for ozone breakdown
125
How are nitrogen oxides created
Thunderstorms and aircraft
126
Equations to show how nitrogen oxide radicals breakdown ozone
127
Order of practical techniques to purify a substance
* Heat under reflux **or** distil
* Seperation
* Drying
* Re-distillation
128
Benefit of heating under reflux
Prevnts any substances escaping
129
Benefit of distillation
Can control a reaction by removing a product before it further reacts
130
Labelled diagram of heating under reflux
131
Labelled diagram of distillation
132
Describe purification by seperation if organic layer is less dense than aqueous layer
* Use a seperating funnel
* Remove bottom layer
* Keep desired top organic layer
* As organic layer less dense than aqueous layer
133
Describe purification by seperation if organic layer is more dense than aqueous layer
* Use seperating funnel
* Remove desired bottom organic layer
* As organic layer more dense than aqueous layer
134
Describe purification by drying
* Add anhydrous salt to organic layer
* Such as anhydrous CaCl2 or anhydrous MgSO4
135
Describe purification by redistillation
* Redistill
* Collect fraction distilling at XYZc
136
Define a Functional Group
A group of atoms that is responsible for the molecules chemical properties and reactions
