Organic Chemistry Flashcards
1
Q
What is a homologous series?
A
group of compounds that can all be represented by the same general formula
2
Q
What do molecules in a homologous series contain?
A
the same functional group
3
Q
What is a functional group?
A
a group of atoms that determine how a compound usually reacts
4
Q
What are the first six stems in a carbon chain?
A
meth eth prop but pent hex
5
Q
what is the prefix for alkanes?
A
ane
6
Q
What is the prefix for alkenes?
A
ene
7
Q
What is the prefix for alcohols?
A
ol
8
Q
What is the prefix for carboxylic acid?
A
oic acid
9
Q
What is the prefix for esters?
A
alkyl
anoate
10
Q
What is an isomer?
A
two molecules with the same molecular formula but the atoms are arranged differently - different structural formula
11
Q
What do isomers have incomen?
A
similar chemical properties
12
Q
What do isomers have differently?
A
physical properties - boiling point
13
Q
What can some isomers have?
A
different functional group - different physical and chemical properties
14
Q
What is crude oil?
A
a mixture of substances which can be separated by fractional distillation
15
Q
What is crude oil seperated in?
A
fractioning column
16
Q
Where is the shortest number of carbon chains in the fractioning column?
A
at the top
17
Q
Where is the hottest place in a fractioning column?
A
bottom
18
Q
What 6 fractions do you get in a fractioning column?
A
- refinery gases
- gasoline
- kerosene
- diesel
- fuel oil
- bitumen
19
Q
Explain how a fractioning column works?
A
- oil heated until most of it has turned to gas, enters column
- when the substances reach part of column where temp is lower then their boiling point they condense
- bubble caps stop the separated liquids from running back down and remixing.
20
Q
What might each fraction contain?
A
saturated or unsaturated hydrocarbons
21
Q
What is a saturated hydrocarbon?
A
only contains single bonds
22
Q
What is an unsaturated hydro carbon?
A
have double or triple bonds between carbon atoms
23
Q
What is cracking?
A
splitting up long chain hydrocarbons
24
Q
Describe long hydrocarbons?
A
high boiling points and viscous
25
Describe shorter hydrocarbons?
lower boiling point and much thinner + paler
26
Which is in more demand ( shorter of longer hydrocarbons)
short-chain
27
What is done to meet short chain demand?
long chain molecules are split using cracking
28
What is cracking a form of?
thermal decomposition
29
describe cracking?
- vaporised hydrocarbon are passed over a powdered catalyst
- 600-700 degrees Celsius
- silica or alumina are used as catalyst
30
What happens when you burn a fuel?
releases energy to form heat
31
Why do hydrocarbons make great fuels?
because combustion reactions that happen when you burn them in oxygen give out lots of energy
32
Give the word equation for when a hydrocarbon burns in plentiful supply of oxygen? ( complete combustion)
hydrocarbon + oxygen -> carbon dioxide + water
33
What happens if there is not enough oxygen for complete combustion to occur?
incomplete combustion
34
What does incomplete combustion make?
carbon dioxide + water + carbon monoxide + carbon
35
What is the problem with carbon monoxide?
combines with red blood cells and stops blood doing its job of carrying oxygen around the body
36
What is acid rain caused by?
sulfer dioxide and nitrogen oxides
37
what happens when fractions from crude oils are burned as fuels?
- sulfer dioxide and nitrogen oxides may be produced
38
What does sulfer dioxide come from?
sulfer impurities in the hydrocarbon fuels
39
What are nitrogen oxides from?
when temp is so high nitrogen reacts with air
40
What happens when sulfer dioxide and nitrogen oxides mix together with water vapour in the clouds?
- form dilute sulphuric acid and nitric acid
41
What is the problem with acid rain?
causes lakes to become acidic and many plants and animals die as a result
42
What are alkanes?
saturated hydrocarbons
43
What is the alkanes general formula?
CnH2n+2
44
What are the first 5 alkanes?
```
methane
ethane
propane
butane
pentane
```
45
What does an alkane + oxygen ->?
carbon dioxide + water
46
What do halogens react with alkanes to form?
haloalkanes
47
What do chlorine + bromine react with alkanes in the presence of?
UV light
48
methane + bromine ->?
bromomethane + hydrogen bromide
49
What do alkenes have?
double bond between two of the carbon atoms in their chain
50
What are alkenes?
unsaturated molecules because they can make more bonds
51
What are the first three alkenes?
ethene, propene, butene
52
What is the general formula of alkenes?
CnH2n
53
What do halogens form when they react with alkenes?
haloalkanes
54
ethene + bromine ->
dibromoethane
55
What is the reaction called when a alkene + halogen react together?
addition reaction because the carbon to carbon double bond is split and a halogen atom is added to each of the carbons
56
Explain how to test for carbon to carbon double bonds?
- shake an alkene with orange bromine water, becomes colourless
- stay orange with alkane
57
What is the functional group of alcohols?
OH
58
What is the general formula of alcohols?
CnH2n+1OH
59
What can alcohols be oxidised to form?
carboxylic acids
60
What do you need to oxidise alcohols?
potassium dichromate in dilute sulphuric acid
61
ethanol (with pressense of potassium dichromate/ sulfuric acid) ->
ethanoic acid
62
What does microbial oxidation form?
carboxylic acids from alcohols
63
What are some microorganisms able to use some alcohols as? what is made as a by product
- energy store
| - carboxylic acid
64
What happens to alcohols when they are burned?
oxidised - complete combustion
65
ethanol + oxygen ->
carbon dioxide + water
66
What can ethanol be produced from?
ethene and steam
| fermentation
67
Explain how ethanol can be produced by steam and ethene?
- ethene is produced from crude oil
- ethene will react with steam - addition reaction
- temperature needs to be 300 degrees celcius
- 60-70 atmospheres of pressure
- phosphoric acid as catalyst
68
What is the advantage of ethanol form steam and ethene?
- cheap process
| - not much wasted
69
What is the disadvantage of ethanol form steam and ethene?
crude oil is non renewable, will become expensive
70
What is the alcohol in beer and wine made from?
fermentation
71
What is the raw material for fermentation?
sugar
72
What is the sugar in fermentation converted into?
ethanol using yeast
73
Describe the conditions fermentation?
- yeast cells contain enzymes which are natural catalysts
- 30 degrees Celsius so enzymes don't denature
- anaerobic conditions
74
What are the advantages of fermentation?
- renewable source
- suger is grown as a major crop around world
- yeast is easy to grow
75
What are the disadvantages of fermentation?
- ethanol isn't very concentrated - has to be distilled
| - needs to be purified
76
What is the functional group of carboxylic acids?
COOH
77
What are the first 4 names of the carboxylic acids?
methanoic acid
ethanoic acid
propanoic acid
butanoic acid
78
What can carboxylic acids react to form?
salts - ending in annotate
79
What will carboxylic acids in aqueous solutions form when reacted with metal carbonates?
salt, water, carbon dioxide
80
aqueous carboxylic acid + metal ->
salt + hydrogen
81
Ethnoic acid + sodium carbonate =
sodium ethanoate + water + CO2
82
ethnic acid + magnesium =
magnesium ethanoate + hydrogen
83
What do carboxylic acids react with alcohols to form esters in the presence of?
an acid catalyst
84
What does vinegar contain?
carboxylic acid
85
How can ethnic acid be made?
oxidising ethanol
86
ethanol + oxygen =
ethanoic acid + water
87
Ethanoic acid can be dissolved in water to form?
vinegar
88
alcohol + carboxylic acid ->
ester + water
89
What is the functional group of esters?
COO
90
ethanol + ethanoic acid -> ?
ethyl ethanoate + water
91
Explain how to make esters in a lab?
- add few drops of concentrated sulfuric acid to boiling tube
- add 10 drops of ethnic acid
- add equal volume of ethanol
- place boiling tube in beaker of water on a tripod
- heat until boiling
- after 1 min allow tube to cool
- pour mixture into test tube of sodium carbonate solution and mix
- layer of ester should form on top
92
What are esters used in?
perfumes because of pleasant smells
| food flavourings
93
What can polymers be made into?
condensation polymerisation
94
What do condensation polymerisation usually involve?
two differant types of monomer
95
What happens when monomers react together?
bonds form between them, making polymer chains
96
WHat does each polymer have to contain?
has to contain at least two functional groups, one on each end of molecule
97
What can each functional group react with?
functional group of another monomer, creating long chains of alternating monomers, for each new bond that forms, a small molecule is lost
