Topic 6 - Organic Chemistry 1 Flashcards
(119 cards)
1
Q
What is the structure of an alkane?
A
only a C-C
2
Q
What is the structure of an alkene?
A
C=C
3
Q
What is the structure of an alcohol?
A
-OH
4
Q
What is the structure of a carboxylic acid?
A
-COOH
5
Q
What is the structure of an ester?
A
- C=O
- O-C
6
Q
What is the structure of an aldehyde?
A
-C=O
-H
(must be on end carbon)
7
Q
What is the structure of a ketone?
A
-C=O
must not be on end carbon - something else comes of carbon
8
Q
What is the structure of a halogenoalkane?
A
-X
X=halogen
9
Q
What is the structure of an amine?
A
-NH2
10
Q
What is the structure of an amide?
A
- C=O
- NH2
11
Q
What does the name of an alkane end in?
A
-ane
12
Q
What does the name of an alkene end in?
A
-ene
13
Q
What does the name of an alcohol end in?
A
-ol
14
Q
What does the name of a carboxylic acid end in?
A
-oic acid
15
Q
What does the name of an ester end in?
A
-yl -oate
16
Q
What does the name of an aldehyde end in?
A
-al
17
Q
What does the name of a ketone end in?
A
-one
18
Q
What does the name of a halogenalkane end in?
A
-ane
19
Q
What does the name of an amine end in?
A
-yl amine
20
Q
What does the name of an amide end in?
A
-amide
21
Q
What do you call a 1 carbon chain?
A
meth
22
Q
What do you call a 2 carbon chain?
A
eth
23
Q
What do you call a 3 carbon chain?
A
prop
24
Q
What do you call a 4 carbon chain?
A
but
25
What do you call a 5 carbon chain?
pent
26
What do you call a 6 carbon chain?
hex
27
What do you call a 7 carbon chain?
hept
28
What do you call a 8 carbon chain?
oct
29
What do you call a 9 carbon chain?
non
30
What do you call a 10 carbon chain?
dec
31
What do you call an additional CH3 joined to a main carbon chain?
methyl
32
What do you call an additional CH2CH3 joined to a main carbon chain?
ethyl
33
What do you call an additional CH2CH2CH3 joined to a main carbon chain?
propyl
34
What do you call an additional F joined to a main carbon chain?
fluoro
35
What do you call an additional Cl joined to a main carbon chain?
chloro
36
What do you call an additional Br joined to a main carbon chain?
bromo
37
What do you call an additional I joined to a main carbon chain?
iodo
38
What do you call an additional OH joined to a main carbon chain?
hydroxy
39
What do you call an additional NH2 joined to a main carbon chain?
amino
40
What is an isomer?
different arrangement of atoms with the same molecular formula
41
What are the three types of structural isomers?
carbon chain isomers
positional isomers
functional group isomers
42
What are carbon chain isomers?
isomers with different lengths of carbon chain
43
What are positional isomers?
isomers with different positions of functional groups
44
What are functional group isomers?
isomers with different functional groups
45
What are geometric isomers?
a type of stereoisomers where there is little rotation around a double C=C bond when there are different groups around the carbons
- cis and trans
- E/Z
46
What does a molecular formula show?
states numbers of each atom
47
What does an emperical formula show?
simplest ratio of each atom
48
What does a displayed structure show?
all the atoms and bonds
49
What does a structural formula show?
indicates structure but no bonds are shown
50
What does a skeletal formula show?
shows C-C bonds but no carbon or hydrogen atoms
| each kink represents a carbon
51
What happens in an addition reaction?
two or more substances combine to form one product
52
What happens in a substitution reaction?
one atom/group replaces another
53
What happens in an oxidation reaction?
the addition of an oxygen or removal of a hydrogen
54
What happens in a reduction reaction?
the addition of a hydrogen or removal of an oxygen
55
What happens in an elimination reaction?
one group/species is eliminated from an organic substance
56
What happens in a hydrolysis reaction?
water splits an organic molecule into two parts
57
What happens in a polymerisation reaction?
lots of monomers join to form a long polymer chain
58
What happens in a condensation reaction?
two or more substances combine and a small molecule is released in the process
(addition + elimination)
59
alkane + oxygen ->
| complete combustion
water + carbon dioxide
60
What happens in halogenation?
alkane reacts with halogen in UV light
-free radical substitution
three stages involved
1) initiation
2) propagation
3) termination
61
What happens in the 3 stages of halogenation?
1) initiation -homolytic bond breaking to form 2 free radicals
2) propagation -non-radical molecule reacts with a radical to produce a different non-radical and a different radical (no net gain or loss of free radicals)
3) termination -radicals react together to form uncharged molecules
62
What is heterolytic bond breaking?
bond breaks unevenly so that one of the bonding atoms receives both electrons from the bonding pair of electrons to form a cation and an anion
eg. X-Y -> X- + Y+
(double headed arrow used)
63
What is homolytic bond breaking?
bond breaks evenly so that each bonding atom receives one electron from the bonding pair of electrons to form two radicals
eg. X-Y -> X• + Y•
(two single headed arrows used)
64
What is crude oil?
a mixture of hydrocarbons
| -can be known as petroleum
65
What does fractional distillation do?
convert crude oil into smaller fractions
66
What are the steps in fractional distillation?
-crude oil is heated and vaporises
-enters fractioning column (with conc gradient -hottest at bottom)
-hydrocarbons rise up through trays and condense at different points (because they have different bps) and run off
bottom -longer chains condense (high bps)
top -shorter chains condense (low bps)
67
What does cracking do?
breaks long chain hydrocarbons into shorter chain hydrocarbons
68
What are the two types of cracking?
thermal cracking
| catalytic cracking
69
What does thermal cracking require?
high temps and high pressure
70
What does thermal cracking produce?
alkenes
71
What does catalytic cracking require?
zeolite catalyst (Al2O3)
low pressure
low temp
72
What does reforming do?
converts straight chain hydrocarbons into branched chain hydrocarbons and cyclic hydrocarbons for efficient combustion
73
Why do straight chain hydrocarbons burn less efficiently?
because of knocking/exploding
74
When alkanes are burned what pollutants can be produced?
- carbon monoxide (produced from incomplete combustion. Binds with haemoglobin in blood which prevents transport of oxygen -toxic)
- oxides of nitrogen (produced when nitrogen reacts with oxygen at high temps. Can cause acid rain)
- oxides of sulphur (produced when sulphur reacts with oxygen to form SO2 which can form other sulphur oxides in atmosphere. Can cause acid rain)
- carbon particles (produced from incomplete combustion. Can be breathed in and cause coughing, headaches, heart diseases, etc)
75
What is a catalytic converter?
metals (platinum, rhodium and palladium) spread over honey comb-like mesh
- increases SA for reactions
- removes pollutants (eg. CO, unburned hydrocarbons, etc) when exhaust gases pass over it
76
Why is a honeycomb structure used in a catalytic convertor?
- increases SA (has more active sites)
| - allows gases to pass through
77
What alternative fuels are there to fossil fuels?
biofuels (during photosynthesis crops take in CO2 and produce sugars/oils which can be burned as fuels -when burned they have no effect on CO2 in atmosphere ∴ carbon neutral)
- bioethanol (ethanol from fermentation of sugar from crops)
- biodiesel (made by refining renewable fats/oils)
- biogas (made by breaking down organic waste matter)
78
What is the test for double bonds?
bromine water
| -changes from orange to colourless
79
Why are alkenes highly reactive?
-they have a double bond
80
alkene + oxygen ->
| complete combustion
carbon dioxide + water
81
What is the difference between the complete combustion of a straight chain alkene and a cycloalkene?
straight chains burn cleanly
| cycloalkenes burn with a sooty flame
82
alkene + potassium manganite ->
diol
| double bond is oxidised, only occurs in acidic conditions, potassium manganite turns colourless
83
alkene + halogen ->
dihalogenoalkane
84
alkene + hydrogen halide ->
halogenoalkane
| electrophilic additon, carbocation intermediate formed
85
What is an electrophile?
a species with a positive charge which is attracted to areas of high electron density
86
What is a carbocation?
an organic molecule containing a carbon atom which is deficient in one electron so has a positive charge
87
alkene + steam ->
alcohol
| acid catalyst
88
alkene + hydrogen ->
alkane
| nickel catalyst + 150° or palladium catalyst + room temp
89
Which carbocation is most stable?
tertiary carbocation
| -because it has 3 methyl groups that can donate electron density inwards to stabilise positive charge
90
What does Markovnikof's rule state?
the hydrogen atom initially adding onto the organic molecule will add to the carbon of the double bond that already has the most hydrogens
-this forms a more stable carbocation and hence the major product
91
What can be done with waste polymers?
- recycled (melted + remoulded)
- incinerated (burned to release energy -toxic gases can be released in the process)
- reused as feedstock in cracking
- buried in landfill
92
What solutions are there to polymer disposal?
- limit waste products
- develop biodegradable polymers (expensive)
- minimise energy use (eg. use catalysts)
- use less other materials
- use more renewable materials
93
What are the properties of halogenoalkanes?
- bps higher than alkanes but lower than alcohols (can from London forces and PD interactions)
- generally insoluble in water (no H-bonds except fluoroalkanes)
- readily react with nucleophiles (in nucleophilic substitution, nucleophiles attack their 𝛿+ carbon)
94
What is a nucleophile?
a negative ion/molecule with a lone pair of electrons that attacks areas of positive charge
95
halogenoalkane + aqueous potassium hydroxide ->
alcohol (+halide ion)
| nucleophilic substitution where OH- (from water) acts as nucleophile and attacks 𝛿+ carbon
96
halogenoalkane + alcoholic potassium hydroxide ->
alkene (+water +halide ion)
| elimination where OH- acts as a base and takes H from halogenoalkane
97
halogenoalkane + aqueous silver nitrate ->
alcohol
(reacts with water, substitution)
precipitate forms from silver nitrate (white = AgCl, cream = AgBr, yellow = AgI)
98
halogenoalkane + potassium cyanide ->
nitrile
| reflux, CN- acts as nucleophile
99
halogenoalkane + ammonia ->
amine
| heated in sealed vessel, concentrated ammonia in excess
100
Do chloro, bromo or iodo alkanes react the fastest?
iodoalkanes have the fastest rate
-iodine is the largest atom so forms longer (weaker) bonds which require less energy to break
chloroalkanes have the slowest rate
-chlorine is the smallest atom so forms shorter (stronger) bonds which require more energy to break
101
Do primary, secondary or tertiary halogenoalkanes react the fastest?
tertiary halogenoalkanes have the fastest rate
-form a more stable carbocation
primary halogenoalkanes have the slowest rate
-form unstable carbocation so waits to be attacked by water molecule rather than forming a carbocation -this takes longer
102
What are the properties of alcohols?
- high bps (can H-bond)
- shorter chain alcohols are soluble in water (can H-bond with water) whereas long chain alcohols are insoluble in water (long hydrophobic tails disrupt potential H-bonds)
- reactive (act as nucleophiles due to their lone pair of electrons on the oxygen)
103
alcohol + oxygen ->
| combustion
carbon dioxide + water
104
alcohol + pentachloride ->
chloroalkane (+POCl3 +HCl)
105
alcohol + sulfuric acid + potassium bromide ->
bromoalkane (+ water)
| acid and potassium bromide produces hydrogen bromide, which then reacts with the alcohol
106
alcohol + red phosphorus + iodine ->
iodoalkane (+HPO3)
(reflux, phosphorus and iodine produce phosphorus(III)iodide which then reacts with the alcohol, iodoalkane can be distilled off)
107
alcohol + phosphoric acid ->
| (H3PO4)
alkene + water
| elimination, phosphoric acid acts as a catalyst
108
What oxidising agent is used to oxidise alcohols?
```
potassium dichromate (VI)
(K2Cr2O7)
```
109
What is produced when a primary alcohol is oxidised?
```
aldehyde (partial oxidation)
carboxylic acid (full oxidation)
```
110
What happens in the partial oxidation of a primary alcohol?
- distillation
- potassium dichromate and H+ present
- aldehyde and water formed
111
How can you test for an aldehyde?
add Benedict's/Fehling's solution
+ve result: colour change from blue to brick red
-Cu2+ ions are reduced to CuO (a red ppt)
112
What happens in the full oxidation of a primary alcohol?
- reflux (vertical condenser with open top)
- potassium dichromate and H+ present
- carboxylic acid and water produced
113
How can you test for a carboxylic acid?
add calcium/sodium carbonate
| +ve result: fizzing and bubbling
114
What is produced when a secondary alcohol is oxidised?
ketone
115
What happens in the oxidation of a secondary alcohol?
- reflux
- potassium dichromate used as oxidising agent
- ketone produced
116
Why can tertiary alcohols not be oxidised?
it can not form any oxygen double bonds (because there are methyl and hydroxy groups attached to carbon)
117
What is a separating funnel used for and how is it used?
to separate an organic product and water (and any soluble impurities)
- product and water are shaken in funnel
- organic layer and aqueous layer (containing impurities) don't mix (are immiscible) so separate into 2 layers
- the layers can be run off separately
118
What can anhydrous salts be used for and how are they used?
to remove traces of water
- salt is used as a drying agent by binding to water molecules to become hydrated
- mixture can be filtered afterwards to remove salt
119
How do anti-bumping granules prevent bumping?
- distribute heat more evenly
| - provide a surface for bubbles to form
