Organic Chemistry Flashcards
1
Q
Give the systematic IUPAC name for C2H5OH
A
Ethanol
2
Q
Give the systematic IUPAC name for C2H4
A
Ethene
3
Q
Give the systematic IUPAC name for C2H6
A
Ethane
4
Q
Give the systematic IUPAC name for C2H5Cl
A
Chloroethane
5
Q
Give the systematic IUPAC name for C2H4Br2
A
1,2,dibromoethane
6
Q
When ethene is converted to C2H4Br2, what type of reaction occurs ?
A
Addition
7
Q
When C2H5OH is converted to C2H4, what type of reaction occurs ?
A
Elimination
8
Q
When C2H4 is converted to C2H6, what type of reaction occurs ?
A
Addition
9
Q
When C2H6 is converted to C2H5Cl, what type of reaction occurs ?
A
Substitution
10
Q
Describe the mechanism of the addition conversion between
A
mkk
11
Q
Name the reagent and catalyst required to convert C2H4 to C2H6
A
Hydrogen is the reagent
Nickel is the catalyst.
12
Q
How do you test for C2H4 ?
A
Shake with bromine water solution. The solution goes colourless.
13
Q
C2H5OH can be oxidised under reflux to give a two carbon acid. Name this acid
A
Ethanoic acid.
14
Q
Name the flavouring agent that contains ethnic acid
A
Vinegar
15
Q
Distinguish between the terms aliphatic and aromatic hydrocarbons.
A
Aliphatic hydrocarbons consist of straight chains of carbon atoms while aromatic hydrocarbons contain benzene rings.
16
Q
What is meant by term unsaturated ?
A
This means that there are double carbon to carbon bonds present
17
Q
Name a reagent used to test for unsaturation and state the colour change that occurs when the result is positive.
A
Bromine water.
Brown to colourless.
18
Q
Describe a test to distinguish between CH3CHO and CH3COOH
A
Test for oxidation add feeling’s solution and heat it. IT CHANGES FROM BLUE TO RED
19
Q
When C2H5OH is converted to C3H3CHO, what type of reaction occurs ?
A
Oxidation
20
Q
When C3H3CHO is converted to CH3COOH, what type of reaction occurs ?
A
Oxidation
21
Q
When CH3COOH is converted to CH3COOCH3, what type of reaction occurs ?
A
Substitution
22
Q
Name the reagents used in the conversion of CH3CHO to CH3COOH
A
Sodium Dichromate
Sulphuric Acid
23
Q
What are free radicals ?
A
These are atoms whose molecules have an unpaired electron. It is a very reactive atom.
24
Q
How are chlorine free radicals formed during the reaction between methane and chlorine ?
A
Chlorine molecule broken to give two chlorine free radicals.
25
What name is given to a stage where chain reaction is occurring ?
Propagation
26
Identify a hydrocarbon formed during propagation. Explain why only a trace quantity of it is found.
Ethane.
| Reaction between methyl radicals is unlikely.
27
What is a secondary alcohol?
Two carbon atoms attached to carbon to which the OH is attached.
28
Give the systematic IUPAC name for the 2 possible organic products of the oxidation in which no carbon to carbon bonds are broken of butane-1-ol.
Identify clearly which bonds in button-2-ol are broken in this oxidation.
1-butanal
1-butanoic acid
The OH bond and the CH bond of carbon to which OH is attached.
29
What ester formed from methanol and propanoic acid is found in many fruits ?
methyl propionate
30
In the lab experiment to prepare benzoic acid, state and explain the colour change in the flask during the initial heating.
Purple to brown.
| Mn +7 goes to Mn+4
31
In the lab experiment to prepare benzoic acid, name the organic compound that gave rise to the smell of almonds during the heating phase.
Benzaldehyde
32
In the lab experiment to prepare benzoic acid, give two reasons why the solution was acidified with concentrated HCl.
To convert sodium benzoate to benzoic acid.
To neutralise any alkaline remaining in the solution.
33
In the lab experiment to prepare benzoic acid, how would you test the solution to find out if enough acid has been added ?
Use a pH meter to read the pH. It should be less than 7.
34
In the lab experiment to prepare benzoic acid, what was the purpose of adding the sodium sulfite solution ?
It reduces manganese.
35
In the lab experiment to prepare benzoic acid, why was the flask placed in ice before filtration.
To ensure all benzoic acid crystallises out of solution.
36
In the lab experiment to prepare benzoic acid, how could the crystals have been dried ?
By air drying overnight or by being placed in a desiccator.
37
Describe what happens during secondary sewage treatment.
Breakdown by micro-organisms.
38
Give the systematic IUPAC name for the two isomers of C3H8O.
Propanol
| Propanone.
39
Name the product formed when bromine is added to ethane.
1,2 dibromoethane.
40
Describe the mechanism of the reaction between C2H6 and C2H5Cl
This is the homolysis of the chlorine molecule into free radicals by UV rays.
The chlorine radical reacts with ethane molecule to give HCl and an ethyl radical.
The remaining radicals combine to form molecules.
41
State 3 pieces of experimental evidence for the mechanism of the reaction between C2H6 and C2H5Cl
butane Is formed
42
Describe how you could demonstrate that ethene readily undergoes an addition reaction with bromine water.
Bubble ethene into bromine water. The red bromine solution decolorised.
43
Would you expect benzene to readily undergo an addition reaction with bromine water ? why?
No.
| Benzene is stable
44
What does the term delocalised mean ?
This means the molecule is shared between more than two atoms.
45
How many electrons in a benzene molecule are delocalised.
6
46
How many electrons in a benzene molecule are involved in sigma bonds between carbon atoms.
12
47
What health hazard is associated with benzene
Carcinogenic
48
State and explain the effect of adding a little tetraethyl lead to an equimolar mixture of methane and chlorine exposed to weak sunlight.
The reaction rate increases because tetraethyl lead acts as a catalyst. it initiates the reaction and provides free radicals.
49
What is a primary alcohol ?
This is one carbon atom attached to carbon to which the OH group is attached.
50
Explain why the boiling point of propane is much higher than that of butane.
Propanal has dipole dipole forces while butane has weaker intermolecular forces.
51
Explain why the boiling point of ethanoic acid is much higher than that of propane-1-ol.
Ethanoic acid has more hydrogen bonds than propan-1-ol. Ethanoic acid has 2 polar groups while propan-1-ol has only one polar group.
52
What is the organic product of the reaction of propanal with acidified KMnO4?
Propanoic acid.
53
Write a balanced equation for the reaction that occurs between sodium and propan-1-ol.
2CH3CH2CH2OH + 2Na = 2CH3CH2CH2ONa + H2
54
What is a volatile liquid ?
This is a liquid with a low boiling point. They evaporate easily.
55
Name the polymer formed when chloroethane undergoes addition polymerisation.
Polychloroethane.
56
Write the molecular formula of eugenol.
C10H12O2
57
Name a spectroscopic technique that could hep to confirm the identity of a sample of eugenol.
Mass spectrometry.
58
What is the overall colour change that occurs in the reaction vessel as phenylmethanol is converted to benzoic acid.
Colorless to purple to brown to colourless.
59
Suggest a weak oxidising agent that can be used to distinguish between a sample of propanol and propanone.
Tollens reagent
Benedicts reagent
Fehlings reagent.
60
Name an ester that is a structural isomer of propanoic acid.
methyl ethanoate.
61
Identify the alcohol and the carboxylic acid used in the synthesis of methyl ethanoate.
methanol
ethanoic acid
62
When clove oil is extracted from an emulsion of clove oil and water, state the colour of the emulsion.
A cloudy liquid
63
When clove oil is extracted from an emulsion of clove oil and water, state the name of the solvent used.
Cyclohexane
64
When clove oil is extracted from an emulsion of clove oil and water, in which layer is the clove oil to be found.
The top layer
65
When clove oil is extracted from an emulsion of clove oil and water, outline the procedure to isolate and dry the clove oil.
The lower aqueous layer us collected in the beaker. A drying agent is added. The solution is filtered and the solvent is allowed to evaporate.
66
When clove oil is extracted from an emulsion of clove oil and water, What safety procedure must be carried out during the extraction ?
Open the top of the separating funnel to release the pressure of any vaporised liquid.
67
When clove oil is extracted from an emulsion of clove oil and water, name the main constituents of oil of cloves.
Eugenol.
68
Name the aromatic compound that is used as a preservative that is a carboxylic acid.
Benzoic acid
69
Outline the mechanism for the monochlorination of ethane.
State 3 clear pieces of evidence which supports this mechanism
Free radical substitution
Inititation
Propagation
Termination
Reaction will occur when uv light only is used.
Butane is present in the resulting mixture
The presence of tetraethyl lead as a source of free radicals greatly speeds up reaction.
70
Which of the 2 compounds, C2H6 and CH3CHO reacts with Fehlings solution ?
State the colour change and the organic product of the reaction.
CH3CHO
Blue to Red
Ethanoic acid.
71
What is used to convert ethanol to ethene.
What organic reaction type is involved in the conversion?
How does the geometry around the carbon atoms change in the conversion ?
Sulphuric acid or aluminium oxide
Elimination or Dehydration
They change from tetrahedral to planar.
72
What organic reaction type is involved in the conversion of ethane to chloroethane.
Substitution.
73
What ester is formed when ethanol is heated with methanol acid and a few drops of sulphuric acid acting as a catalyst ?
Ethyl methanoate.
74
What name is given ti the type of reaction that occurs between sodium hydroxide and Ethylmethanoate
Base hydrolysis
| Saponification.
75
Define unsaturated
Consisting of at least one multiple carbon to carbon bond.
76
Describe the mechanism of the reaction between bromine water an ethene.
Give the names of the 3 products that would be formed if the bromine water used in the reaction contained sodium chloride.
Polarisation of Br2
addition of bromonium ion across the double bond
Attack of bromide ion to the bridged intermediate.
1,2- dibromoethane
2-bromoethanol
1-bromo-2-chloroethane.
77
In the lab experiment to prepare benzoic acid, why was an excess solution of potassium manganate (VII) used in this reaction ?
To ensure a complete oxidation of the alcohol to the acid.
78
In the lab experiment to prepare benzoic acid, identify the brown precipitate formed in the reaction.
MnO2
79
In the lab experiment to prepare benzoic acid, how would you test the solution to find out if enough acid has been added ?
Use pH meter to read . It should have a pH less than 7.
80
In the lab experiment to prepare benzoic acid, what reaction occurred when the sodium sulfite was added ?
This reduces manganese (IV) Mn+4 to Mn+2
81
Name 2 additives two increase the octane number of fuel.
Methanol
| ethanol
82
Ethanoic acid reacts with the base sodium carbonate. write out the balanced equation for this
2CH3COOH + Na2CO3 = 2CH3COONa + CO2 + H20
83
Describe how you would test a given hydrocarbon for unsaturation.
Buy adding bromine water to it. Bromine water decolorises unsaturated compounds.
84
Explain wether or not the kekulé structure correctly describes the number of the pi electrons in benzene.
Yes it does because each of the 3 double bone has 2 pi - electrons.
85
Explain wether or not the kekulé structure correctly describes the distribution of the pi electrons in benzene.
Give one piece of experimental evidence to support this.
The electrons in benzene are delocalised whereas in the structure they are localised.
Benzene is chemically stable. It is therefore unreactive.
86
Name the addition polymer formed form C3H6
Polypropene
87
Identify the bonds broken and the bonds formed in the conversion of CH3COCH3 to CH3CHOHCH3
The pi bond between the C and O were broken.
The bonds formed were. the OH bond and the CH bond.
88
An isomer of CH3CHOHCH3 can be synthesised from an aldehyde. Name the isomer and the aldehyde.
1-propanol is the isomer
| Propanal is the aldehyde.
89
In the lab production of ethyne gas, identify the liquid and solid involved.
The liquid is water
| The solid is calcium dicarbide
90
In the lab production of ethyne gas, describe the appearance of the solid used
Black
| Grey
91
In the lab production of ethyne gas, write a balanced equation for the reaction between the sold and liquid producing ethyne.
CaC2 + H2O = C2H2 + CaO
92
State the type of reaction involved in the test for unsaturation.
Addition reaction.
93
Give the common name for ethyne and state one major use of the gas.
Acetylene
| It is used in welding.
94
In which of the 2 solvents, water or methylbenzene is ethyne soluble ? Explain.
It is soluble in methylbenzene. This is because it is covalent and covalent compounds dissolve in organic solvent.
95
Name a common use of propanone.
Nail varnish remover.
