1.
Which of the structures below is an aldehyde?
O
A.
2.
CH 3 CCH3
C.
D. CH 3 COCH3
CH 3 CH 2COH
CHBrCHBr
B. CH2CHBr
C.
CH3CH2Br
D.
CH2BrCH2Br
What is the final product formed when CH3CH2OH is refluxed with acidified potassium
dichromate(VI)?
A.
4.
B.
CH 3CH 2CH
O
O
What product results from the reaction of CH2==CH2 with Br2?
A.
3.
O
CH3CHO
B.
CH2==CH2
C.
CH3COOH
D.
HCOOCH3
Which of the substances below is least soluble in water?
O
O
A.
CH2OHCHOHCH2OH
B.
C H3 C C 3H
C.
CH 3 CH 2 COH
O
D.
CH3 COCH3
5.
6.
Which substance(s) could be formed during the incomplete combustion of a hydrocarbon?
I.
A.
7.
I only
B.
II.
Hydrogen
I and II only
C.
III.
Carbon monoxide
I and III only
D.
II and III only
III.
(CH3)3CH
Which formulas represent butane or its isomer?
I.
A.
8.
Carbon
CH3(CH2)2CH3
I and II only
B.
II.
CH3CH(CH3)CH3
I and III only
C.
II and III only D.
I, II and III
Which compound can exist as optical isomers?
A.
CH3CHBrCH3
B.
CH2BrCHBrCH3
C.
CH2BrCHBrCH2Br
D.
CHBr2CHBrCHBr2
9.
10.
11.
Which statement about the reactions of halogenoalkanes with aqueous sodium hydroxide is
correct?
A.
Primary halogenoalkanes react mainly by an SN1 mechanism.
B.
Chloroalkanes react faster than iodoalkanes.
C.
Tertiary halogenoalkanes react faster than primary halogenoalkanes.
D.
The rate of an SN1 reaction depends on the concentration of aqueous sodium hydroxide.
Which statement about neighbouring members of all homologous series is correct?
A.
They have the same empirical formula.
B.
They differ by a CH2 group.
1
12.
C.
They possess different functional groups.
D.
They differ in their degree of unsaturation.
Which type of compound must contain a minimum of three carbon atoms?
A.
13.
B.
A carboxylic acid
C.
An ester
D. A ketone
What is the IUPAC name for CH3CH2CH(CH3)2?
A.
1,1-dimethylpropane
B.
2-methylbutane
C.
isopentane
D.
ethyldimethylmethane
14.
Which compound can exist as optical isomers?
A.
15.
An aldehyde
H2NCH2COOH
B.
CH2ClCH2Cl
C.
CH3CHBrI
D.
HCOOCH3
D.
CH3CHBr2
Which product is formed by the reaction between CH2CH2 and HBr?
A.
CH3CH2Br
B.
CH2CHBr
C.
BrCHCHBr
16.
17.
Which reaction(s) involve(s) the formation of a positive ion?
I.
A.
18.
19.
20.
I only
CH3CH2CH2Br + OH–
B.
II only C.
II.
(CH3)3CBr + OH–
Both I and II
D.
Neither I nor II
Which compound has the lowest boiling point?
A.
CH3CH2CH(CH3)CH3
B.
(CH3)4C
C.
CH3CH2CH2CH2CH3
D.
CH3CH2OCH2CH3
Which species will show optical activity?
A.
1-chloropentane
B.
3-chloropentane
C.
1-chloro-2-methylpentane
D.
2-chloro-2-methylpentane
What type of reaction does the equation below represent?
CH2=CH2 + Br2 → BrCH2CH2Br
A.
21.
substitution
B.
condensation
C.
reduction
D.
addition
Consider the following compounds.
I.
CH3CH2CH(OH)CH3
II.
CH3CH(CH3)CH2OH
III. (CH3)3COH
The compounds are treated separately with acidified potassium dichromate(VI) solution. Which
will produce a colour change from orange to green?
A.
22.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
Which compound reacts most rapidly by a SN1 mechanism?
2
A.
23.
27.
1-chloropropene B. 1-chlorobutane
1,1-dichloropropane
CH3CH2CHCH2CH3
CH3(CH3)3CH3
CH3CHO
B.
B.
It involves heterolytic fission and Cl radicals.
C.
It involves homolytic fission and Cl– ions.
D.
It involves homolytic fission and Cl radicals.
B. CH3CHBrCH2CH3
C. (CH3)2CHCH2Br
D.
(CH3)3CBr
butan-1-ol
B.
butan-2-ol
C.
butanone
D. butanoic acid
How many structural isomers are possible with the molecular formula C6 H14?
4
B.
5
C. 6
D. 7
Which compound is a member of the aldehyde homologous series?
CH3COCH3
B. CH3CH2CH2OH
C. CH3CH2COOH
D.
CH3CH2CHO
Which compound can exist as optical isomers?
CH3CHBrCH3 B. CH2ClCH(OH)CH2Cl
CH3CCl2CH2OH
C.
CH3CHBrCOOH
D.
Which type of compound can be made in one step from a secondary alcohol?
A.
33.
CH3COOCH2CH3
Which compound is converted to butanal by acidified potassium dichromate(VI) solution?
A.
32.
D.
Which formula is that of a secondary halogenoalkane?
A.
31.
C. CH3(CH2)3CH3 D.
CH3COOCH3 C. CH3CH2COOCH3
It involves heterolytic fission and Cl– ions.
A.
30.
B. (CH3CH2)2CH3
A.
A.
29.
D.
Which statement is correct about the reaction between methane and chlorine?
A. CH3CH2CH2CH2Br
28.
C. 1-bromopropane
What is the organic product of the reaction between ethanol and ethanoic acid?
A.
26.
D.
Which formula is a correct representation of pentane?
A.
25.
C. (CH3)3CBr
Which compound is a member of the same homologous series as 1-chloropropane?
A.
24.
(CH3)3CCl
B. CH3CH2CH2CH2Br
CH3CH2CH2CH2Cl
an aldehyde
B.
an alkane
C. a carboxylic acid
D. a ketone
Which formula represents a tertiary alcohol?
3
A.
CH 3
CH
CH 2
CH 3
CH3
B.
CH
CH 2OH
C.
C
CH 2
CH
CH3
D.
CH 2
CH 3
CH3
CH 3
CH
OH
34.
35.
OH
Which reaction type is typical for halogenoalkanes?
A.
nucleophilic substitution
B.
electrophilic substitution
C.
electrophilic addition
D.
nucleophilic addition
Which substance is not readily oxidized by acidified potassium dichromate (VI) solution?
A.
36.
OH
CH 3
CH 3
CH 3
CH 2
propan-1-ol
B.
propan-2-ol
C.
propanal
D.
propanone
What is the correct name of this compound?
CH3
CH
CH3
CH2
CH 2
CH 3
37.
A. 1,3-dimethylbutane
B. 2,4-dimethylbutane
C. 2-methylbutane
D.
2-methylpentane
Propane, C3H8, undergoes incomplete combustion in a limited amount of air. Which products
are most likely to be formed during this reaction?
A.
Carbon monoxide and water
B.
Carbon monoxide and hydrogen
C.
Carbon dioxide and hydrogen
D.
Carbon dioxide and water
38. What is/are the product(s) of the reaction between ethene and hydrogen bromide?
39.
A.
CH3CH2Br
B.
CH3CH2Br and H2
C.
CH2BrCH2Br
D.
CH3BrCH2 Br and H2
Which are characteristics typical of a free radical?
I.
II.
III.
A.
40.
It has a lone pair of electrons.
It can be formed by the homolytic fission of a covalent bond.
It is uncharged.
I and II only
B.
I and III only
C.
II and III only D.
I, II and III
Which of the following products could be formed from the oxidation of ethanol?
I.
ethanal
II.
ethanoic acid
III.
ethane
4
A.
41.
42.
43.
46.
II and III only D.
B.
Methanol and ethanoic acid
C.
Ethanol and ethanoic acid
D.
Methanol and methanoic acid
I, II and III
Which pair of compounds can be used to prepare CH3COOCH3?
A.
Ethanol and methanoic acid
B.
Methanol and ethanoic acid
C.
Ethanol and ethanoic acid
D.
Methanol and methanoic acid
What is the reaction type when (CH3)3CBr reacts with aqueous sodium hydroxide to form
(CH3)3COH and NaBr?
Addition
B.
Elimination
C.
SN1
D.
D.
:CH3
SN2
Which species is a free radical?
•CH3
B.
+
CH3
C.
–
CH3
Which compound is a tertiary halogenoalkane?
A.
(CH3CH2)2CHBr
B.
CH3(CH2)3CH2Br
C.
(CH3)2CHCH2CH2Br
D.
CH3CH2C(CH3)2Br
Which species reacts most readily with propane?
Br2
B.
Br•
C.
Br–
D.
Br+
Nylon is a condensation polymer made up of hexanedioic acid and 1,6-diaminohexane.
Which type of linkage is present in nylon?
A.
48.
C.
Ethanol and methanoic acid
A.
47.
I and III only
A.
A.
45.
B.
Which pair of compounds can be used to prepare CH3COOCH3?
A.
44.
I and II only
Amide
B.
Ester
C.
Amine D.
Carboxyl
How many chiral carbon atoms are present in a molecule of glucose?
A.
1
B.
2
C.
3
D.
4
5
49.
An organic compound X reacts with excess acidified potassium dichromate(VI) to form
compound Y, which reacts with sodium carbonate to produce CO2(g).
What is a possible formula for compound X?
A.
50.
CH3CH2COOH
B. CH3CH2CH2OH
C. CH3CH(OH)CH3
D.
(CH3)3COH
Which amino acid can exist as optical isomers?
A.
B.
C.
D.
51.
Which statement about successive members of all homologous series is correct?
A.
They have the same empirical formula.
B.
They differ by a CH2 group.
C.
They have the same physical properties.
D.
They differ in their degree of unsaturation.
52.
The following is a three-dimensional representation of an organic molecule.
Which statement is correct?
A.
The correct IUPAC name of the molecule is 2-methylpentane.
B.
All the bond angles will be approximately 90°.
6
53.
C.
One isomer of this molecule is pentane.
D.
The boiling point of this compound would be higher than that of pentane.
Which compound forms when hydrogen bromide is added to but-2-ene?
A.
54.
2-bromobutane
A.
56.
C. 1-bromobutane D.1,2-dibromobutane
Which products can be potentially obtained from crude oil and are economically important?
I.
55.
B. 2,3-dibromobutane
Plastics
I and II only
II. Margarine III. Motor fuel
B. I and III only
C.
II and III only
D.
I, II and III
Propane, C3H8, undergoes incomplete combustion in a limited amount of air. Which products
are most likely to be formed during this reaction?
A.
Carbon monoxide and water
B.
Carbon monoxide and hydrogen
C.
Carbon dioxide and hydrogen
D.
Carbon dioxide and water
What is the product of the following reaction?
Ni
CH3CH2CH2CN + H2 
A.
CH3CH2CH2NH2
B. CH3CH2CH2CH3
C. CH3CH2CH2CH2CH3
57.
D.CH3CH2CH2CH2NH2
What is the correct IUPAC name for the following compound?
CH 3 CHCH 2 CH 2 CN
CH 3
58.
A.
4-methylbutanenitrile
B.
4-methylpentanenitrile
C.
2-methylbutanenitrile
D.
2-methylpentanenitrile
What is the organic product of the reaction between ethanol and ethanoic acid in the presence of
sulfuric acid?
A.
59.
B.
CH3COOCH3 C. CH3CH2COOCH3
D.
CH3COOCH2CH3
Which compound can exist as optical isomers?
A.
60.
CH3CHO
H2NCH2COOH
B.
H3CCONH2
C.
H3CCHBrI
D.
HCOOCH3
Two reactions of an alkene, B, are shown below.
C 4 H 10
A
H2
CH 3
CH 3
Ni
C
C
C
H
C 4 H 9 Br
H
B
(i)
State the name of A and write an equation for its complete combustion. Explain why the
7
incomplete combustion of A is dangerous.
(5)
(ii) Outline a test to distinguish between A and B, stating the result in each case.
(3)
(iii) Write an equation for the conversion of B to C. State the type of reaction taking place and
draw the structure of C.
(3)
61.
(i)
A compound D has the molecular formula C2H4O2 and is obtained from a reaction
between methanoic acid and methanol. Write an equation for this reaction and state the
name of D.
(3)
(ii) A second compound, E, has the same molecular formula as D and has acidic properties.
State the name of compound E.
(1)
62.
The first synthetic thread was made from a polyester. A section of the polyester is drawn below:
–––CH2COO–––CH2COO–––CH2COO–––
(i)
Give the structural formula of the monomer (containing two functional groups) that could
be used to make this polyester and state the names of the two functional groups.
(3)
(ii) State, giving a reason, whether this polyester is made by a condensation reaction or an
addition reaction.
(2)
63.
(a)
Halogenoalkanes undergo nucleophilic substitution reactions. The rates and mechanisms
of these reactions depend on whether the halogenoalkane is primary, secondary or
tertiary. Explain the term nucleophilic substitution.
(2)
(b)
The formula C4H9Br represents more than one compound. Using this formula, draw a
structure (showing all bonds between carbon atoms) to represent a halogenoalkane that is
(i)
primary.
(ii)
secondary.
(iii)
tertiary.
(1)
64.
(i)
Ethanoic acid reacts with ethanol in the presence of concentrated sulfuric acid and heat.
Identify the type of reaction that takes place. Write an equation for the reaction, name the
organic product formed and draw its structure.
(4)
(ii) State and explain the role of sulfuric acid in this reaction.
(2)
(iii) State one major commercial use of the organic product from this type of reaction.
(1)
65.
For the two compounds HCOOCH2CH3 and HCOOCHCH2:
I
II
(i)
State and explain which of the two compounds can react readily with bromine.
(2)
8
(ii)
Compound II can form polymers. State the type of polymerization compound II
undergoes, and draw the structure of the repeating unit of the polymer.
(2)
66.
Identify which of the compounds butane, chloroethane, propanone and propan-1-ol are
(i)
insoluble in water and give your reasoning.
(2)
(ii) water soluble and give your reasoning.
(2)
67.
(a)
(i) Draw the two enantiomers of 2-hydroxypropanoic acid.
(2)
(ii) State how the two enantiomers differ in their chemical and physical properties.
(2)
68.
The compound C2H4 can be used as a starting material for the preparation of many substances.
(a)
Name the compound C2H4 and draw its structural formula.
(2)
(b)
In the scheme below, state the type of reaction and identify the reagent needed for each
reaction.
A
B
C2H4 → CH3CH2OH → CH3COOH
(4)
(c)
C2H4 can be converted into one of the compounds below in a single step reaction.
C2H3Cl
C2H4Cl2
Draw the structural formula for each of these compounds and identify the compound
which can be formed directly from C2H4.
(3)
(d)
One of the two compounds in (c) has an isomer. Draw the structural formula of the
isomer and explain why it can not be formed directly from C2H4.
(2)
(e)
C2H4 can also react to form a polymer. Name this type of polymer and draw the structural
formula of a section of this polymer consisting of three repeating units.
(2)
(f)
Polymers can also be formed in a different type of reaction. Identify this type of reaction
and name two different types of such polymers.
(3)
69.
The polymer with the repeating unit
H
H
O
N
C
C
CH 3
exists as optical isomers.
9
(i)
(ii)
State a test for optical isomers.
Identify the chiral centre in the repeating unit.
(iii) Draw the two enantiomeric forms of the repeating unit.
70.
Bromoethane reacts with ammonia as follows.
CH3CH2Br + NH3 → CH3CH2NH3+ + Br–
CH3CH2NH3+ + NH3 → CH3CH2NH2 + NH4+
The mechanism for this reaction is described as SN2.
(a)
State the meaning of each of the symbols in SN2.
(2)
(b)
State the name of the organic product of the reaction, CH3CH2NH2.
(1)
(c)
Explain, using ―curly arrows‖ to show the movement of electron pairs, the mechanism of
the attack by ammonia on bromoethane, and show the structure of the transition state.
(4)
71.
The plastic PVC, poly(chloroethene), is made from the monomer chloroethene, C2H3Cl, by a
polymerization reaction.
(i)
Draw the structural formula of chloroethene.
(1)
(ii) State the type of polymerization reaction that occurs to make poly(chloroethene) and
identify the structural feature needed in the monomer.
(2)
(iii)
Draw the structure of the repeating unit of poly(chloroethene).
(1)
(iv) Explain why monomers are often gases or volatile liquids, whereas polymers are solids.
72.
Hexanedioic acid and 1,6-diaminohexane react together to form a synthetic polymer. There are
many natural polymers, some of the most familiar being proteins formed from 2-amino acids.
(i)
Give the structural formula of each monomer in the synthetic polymer.
(2)
(ii)
State the type of polymerization reaction that occurs between these two monomers and
identify the structural feature needed in the monomers.
(2)
(iii) Draw the structure of and state the type of linkage formed in this polymer, and identify
the other product of this polymerization reaction. (3)
(iv) The structures of some 2-amino acids are shown in Table 20 of the Data Booklet. Using
alanine as an example, explain what is meant by the term optical activity, identify the
structural feature that needs to be present and illustrate your answer with suitable
diagrams of both isomers.
(3)
(v)
Identify a 2-amino acid from Table 20 which does not show optical activity. (1)
(vi) Polyesters are formed in a similar polymerization reaction to proteins. Their monomers
are esters. State one use of esters and identify the two compounds that react together to
10
form the ester ethyl methanoate.
73.
(3)
The hydrolysis of 2-iodo-2-methylpropane by 0.10 mol dm–3 KOH(aq) to form
2-methylpropan-2-ol is an example of nucleophilic substitution.
Give equations to illustrate the SN1 mechanism for this reaction. (Total 2 marks)
74.
One of the alcohols containing four carbon atoms exists as optical isomers.
Give the structural formula and name of this alcohol and explain why it exists as optical
isomers. Outline how these two isomers could be distinguished.
75.
The molecular formula C4H9Br represents four structural isomers, all of which can undergo
nucleophilic substitution reactions with aqueous sodium hydroxide. An equation to represent all
these reactions is
C4H9Br + NaOH  C4H9OH + NaBr
(a)
Explain what is meant by the term nucleophilic substitution.
(2)
(b) The main mechanism for a tertiary halogenoalkane is SN1. Give the equations for this
substitution reaction of the tertiary isomer of C4H9Br. Show the structures of the organic
reactant and product and use curly arrows to show the movement of electron pairs.
(4)
(c)
The main mechanism for a primary halogenoalkane is SN2. Give the mechanistic equation
for this substitution reaction of the straight-chain primary isomer of C4H9Br, showing the
structures of the organic reactant and product, and using curly arrows to show the
movement of electron pairs.
(4)
(d)
Give a structural formula for the secondary isomer and for the other primary isomer. State
the name of each isomer.
(4)
77.
Many organic compounds can exist as isomers. Draw and name an isomer of ethanoic acid,
CH3COOH.
78.
Write equations to show the mechanisms of the following reactions. In each case, show the
structure of the intermediate and organic product, and use curly arrows to show the movement
of electron pairs.
(i)
the reaction between KOH and CH3CH2CH2CH2Cl.
3)
(ii)
the reaction between KOH and (CH3)3CCl.
(2)
79.
Some alcohols are oxidized by heating with acidified potassium dichromate(VI). If oxidation
does occur, identify the possible oxidation products formed by each of the alcohols below.
Indicate if no oxidation occurs.
Butan-1-ol
Butan-2-ol
2-methylpropan-2-ol
11
80.
Chlorine and ethane react together to form chloroethane.
(a)
State the condition needed for the reaction to occur.
(1)
(b)
Write equations to represent initiation, propagation and termination steps in the reaction.
81.
CH3COCH3 is the first member of the ketone homologous series. Draw the full structural
formula of the next member of this homologous series and predict how its melting point
compares with that of CH3COCH3.
(Total 2 marks)
82.
Explain why butan-2-ol, CH3CH(OH)CH2CH3, exists as enantiomers, and describe how pure
samples of the enantiomers can be distinguished experimentally.
83.
Polyesters are formed in a condensation reaction. The structure of the repeat unit of a polyester
is
C
O
(i)
C H
C
O
CH
CH
O
O
Draw the structures of the two monomers that react to form this polyester.
(2)
(ii)
Identify the essential feature of the monomers in (i) that enable them to form a
condensation polymer.
(1)
85.
(i)
Write an equation for the reaction between but-2-ene and bromine, showing the structure
of the organic product.
(2)
(ii)
State the type of reaction occurring.
87.
CH3COCH3 can be prepared in the laboratory from an alcohol. State the name of this alcohol,
the type of reaction occurring and the reagents and conditions needed for the reaction.
88.
2-bromobutane can be converted into butan-2-ol by a nucleophilic substitution reaction. This
reaction occurs by two different mechanisms.
(i)
Give the structure of the transition state formed in the SN2 mechanism.
(2)
(ii)
Write equations for the SN1 mechanism.
(2)
91.
Ethene is an unsaturated hydrocarbon used as a starting material for many organic chemicals.
(a)
Draw the structural formula of ethene and state the meaning of the term unsaturated
hydrocarbon.
(2)
(b) State an equation for the conversion of ethene to ethanol and identify the type of reaction.
(2)
(c)
Describe the complete oxidation of ethanol and name the product. Include the conditions,
reagents required and any colour changes.
12
(4)
(d)
State an equation for the reaction between ethanol and the product of complete oxidation
in (c). Include any other reagent required for this reaction. Name the organic product and
state one possible use of this product.
(4)
92.
(i)
State the meaning of the term isomers.
(1)
(ii)
Draw the functional group isomers of C3H6O.
(2)
(iii)
State the meaning of the term optical isomers. Draw the alcohol with the molecular
formula C4H10O which exhibits optical isomerism and identify the chiral carbon atom.
(3)
93.
Ethene is an unsaturated hydrocarbon used as a starting material for many organic chemicals.
(a)
State the meaning of the term unsaturated hydrocarbon.
(b)
State an equation for the conversion of ethene to ethanol and identify the type of reaction.
(c)
Describe the complete oxidation of ethanol. Include the conditions, reagents required and
any colour changes. Name the organic product X.
(d) State an equation for the reaction between ethanol and compound X. Include any other
reagent required. Name the organic compound Z and state one use of this product.
94.
(i)
State the meaning of the term isomers.
(1)
(ii)
Draw the functional group isomers of C3H6O.
(2)
(iii)
State the meaning of the term optical isomers. Draw the alcohol with the molecular
formula C4H10O which exhibits optical isomerism and identify the chiral carbon atom.
(3)
(iv)
Other than the optical isomers in (iii), draw the other three alcohol isomers of molecular
formula C4H10O and identify the isomer that does not undergo oxidation.
(2)
95.
The equation for a reaction of ethane is
CH3CH3 + Cl2  CH3CH2Cl + HCl
The mechanism of this reaction involves initiation, propagation and termination steps. Describe
this reaction, including equations for each step and the role of ultraviolet light.
96.
97.
(i)
Draw the structural formula of the ester propyl ethanoate.(1)
(ii)
Deduce the name and draw the structural formula of the alcohol and carboxylic acid that
react to form this ester.
(i)
Draw the structural formula of propan-2-ol.
(ii)
Identify the alcohol as primary, secondary, or tertiary.
13
(iii) Identify the organic product formed by the oxidation of this alcohol using acidified
potassium dichromate(VI) solution.
98.
Secondary halogenoalkanes can undergo nucleophilic substitution reactions by both SN1 and
SN2 mechanisms. The mechanism showing the formation of the transition state in the reaction
between 2-bromobutane and potassium hydroxide can be represented as follows.
CH 2 CH 3
H
(a)
C
Br
CH3
:OH –
CH 2 CH 3
H
HO
C
Br
CH
Identify the type of mechanism shown.
(1)
(b)
State and explain how the following changes would alter the rate of the reaction by this
mechanism.
(i)
using water instead of potassium hydroxide.
(2)
(ii)
using bromoethane instead of 2-bromobuture.
(2)
99.
The following is a computer-generated representation of the molecule, methyl
2-hydroxy benzoate, better known as oil of wintergreen.
(i)
Deduce the empirical formula of methyl 2-hydroxy benzoate and draw the full structural
formula, including any multiple bonds that may be present.
The computer-generated representation shown does not distinguish between single and
multiple bonds.
(2)
(ii) In this representation, two of the carbon-oxygen bond lengths shown are 0.1424 nm and
0.1373 nm. Explain why these are different and predict the carbon-oxygen bond length in
carbon dioxide.
(2)
(iii) Name all the functional groups present in the molecule.
14
(2)
100. (i)
State and explain the trend in the boiling points of the first six alkanes involving
straight-chains.
(2)
(ii)
Write an equation for the reaction between methane and chlorine to form chloromethane.
Explain this reaction in terms of a free-radical mechanism.
(5)
101. (i)
Identify the formulas of the organic products, A–E, formed in the reactions, I–IV:


I.
H
H
CH3(CH2)8OH + K2Cr2O7 
 A 
 B
II.
(CH3)3CBr + NaOH 
 C
III.
H
(CH3)2CHOH + K2Cr2O7 
 D
IV.
H2C=CH2 + Br2 
 E

(5)
(ii) H2C=CH2 can react to form a polymer. Name this type of polymer and draw the
structural formula of a section of this polymer consisting of three repeating units.
(2)
102. The compound, 2-bromobutane, CH3CHBrCH2CH3, can react with sodium hydroxide to form
compounds F, G and H.
Compound F, C4H10O, exists as a pair of optical isomers. Compounds G and H, C4H8, are
structural isomers, and compound H exists as a pair of geometrical isomers.
(i)
Draw the structures of the two optical isomers of F.
(2)
(ii) Outline the use of a polarimeter in distinguishing between the optical isomers.
(2)
(iii)
Draw diagrams to show the shapes of the two geometrical isomers of H.
(2)
(iv) Draw the mechanism, using curly arrows to represent the movement of electron pairs, to
show the formation of G.
(3)
103. A compound, J, has the molecular formula C2H4O2 and is obtained from a reaction between
methanoic acid and methanol. Write an equation for this reaction and state the name of
compound J.
104. A student prepared a sample of compound Y from benzene as follows:
C6H6 → C6H5CH2CH3 → C6H5CHClCH3
X
Y
(a)
(i)
The first step was the conversion of benzene to compound X, using chloroethane as
the reagent and aluminum chloride as a catalyst. Write the equation for the reaction
and give equations for the mechanism.
(ii)
Name the type of mechanism that occurs in the second step when X is converted
15
to Y.
(1)
(b) (i)
(ii)
Draw two structures for compound Y, showing the relationship between them.
Explain the term plane-polarized light and describe how the optical isomers of Y
could be distinguished using a polarimeter.
(4)
(iii) Explain why the sample of Y produced by the student did not show optical activity.
(c)
Samples of compound Y and chlorobenzene are warmed separately with aqueous sodium
hydroxide. State, with a reason, whether compound Y or chlorobenzene would react more
slowly.
(2)
105. The structure of benzene can be represented in two ways.
structure A
(a)
structure B
Use information from Table 9 of the Data Booklet to explain why structure B is used
instead of structure A.
(2)
(b) The enthalpy changes for the hydrogenation of cyclohexene and benzene are as follows.
C6H10 + H2 → C6H12
Hο = –120 kJ mol–1
C6H6 + 3H2 → C6H12
Hο = –210 kJ mol–1
Explain how this information can be used to support the statement that structure B is
more stable than structure A.
106. The pKb values of some amines are shown in Table 16 of the Data Booklet. Write an equation
for the reaction of ethylamine with water. State and explain how the basicity of ethylamine
compares to that of ammonia.
107. The compound methylbenzene, C6H5CH3, was reacted with chlorine under two different
conditions.
In the presence of aluminium chloride two organic products, F and G, were formed, both with
the molecular formula C7H7Cl.
Under the other set of conditions three organic products, J, K and L, were formed, with
molecular formulas of C7H7Cl, C7H6Cl2 and C7H5Cl3, respectively.
(a)
Deduce the structures of F and G.
(2)
(b) State the type of mechanism that occurs in the formation of F and G.
(1)
(c)
Write equations, using curly arrows to represent the movement of electron pairs, to show
the mechanism of the reaction in which either F or G is formed. Use Cl+ to represent the
16
attacking species.
(d)
(e)
Deduce the structures of compounds J, K and L.
State the type of mechanism that occurs in the formation of J, K and L.
(1)
(f)
Write an equation to show the initiation step that occurs before either J, K or L can be
formed, and state the condition needed.
(2)
(g)
(h)
(i)
Write equations to show two propagation steps in the mechanism for the formation of
compound K.
Write an equation to show a termination step in which compound L is formed.
Predict, giving a reason, whether methylbenzene or compound L undergoes nitration
more readily.
108. The compound 2-bromobutane, CH3CHBrCH2CH3, can react with sodium hydroxide to form
compounds M, N and O.
Compound M, C4H10O, exists as a pair of optically active isomers. Compounds N and O, C4H8,
are structural isomers, and compound O exists as a pair of geometrical isomers.
(a)
Draw diagrams to show the relationship between the two isomers of M.
(2)
(b)
Draw diagrams to show the shapes of the two isomers of O.
(2)
(c)
Write equations, using curly arrows to represent the movement of electron pairs, to show
the mechanism of the reaction in which N is formed.
(3)
109. (a)
The reaction of warm aqueous KOH with 1-bromobutane occurs by an SN2 mechanism.
Draw the mechanism for this reaction, including the structural formulas
of 1-bromobutane, the transition state and the organic product.
(4)
(b)
State and explain how the rate of the above reaction is affected when the concentration of
the KOH is doubled.
(c)
State and explain how the rate of reaction of 1-chlorobutane in the above SN2 reaction
compares with that of 1-bromobutane.
(2)
110. Methylbenzene, C6H5CH3, reacts with Cl2 to form different products depending on the
conditions used. For the gas-phase reaction of C6H5CH3 and Cl2 in ultraviolet light,
(a)
draw a structural formula for the product C7H7Cl.
(b)
provide a stepwise mechanism, clearly labelling each step.
(c)
explain the role of the ultraviolet light.
(1)
111. When hydrogen cyanide reacts with an aldehyde or a ketone the product molecule has one more
carbon atom.
17
(a)
Give a mechanism for the reaction of hydrogen cyanide with propanone.
(b)
Write an equation for the acid hydrolysis of this product. State the two functional groups
in the organic product.
(2)
112. Ethene, propene and but-2-ene are members of the alkene homologous series.
(a)
Describe three features of members of a homologous series.
(3)
(b) State and explain which compound has the highest boiling point.
(3)
(c)
Draw the structural formula and give the name of an alkene containing five carbon atoms.
(2)
(d) Write an equation for the reaction between but-2-ene and hydrogen bromide, showing the
structure of the organic product. State the type of reaction occurring.
(3)
(e)
Propene can be converted to propanoic acid in three steps:
step1
propene
step 2
propan-1-ol
step 3
propanal
propanoic acid
State the type of reaction occurring in steps 2 and 3 and the reagents needed. Describe
how the conditions of the reaction can be altered to obtain the maximum amount of
propanal, and in a separate experiment, to obtain the maximum amount of propanoic acid.
(5)
(f)
Identify the strongest type of intermolecular force present in each of the compounds
propan-1-ol, propanal and propanoic acid. List these compounds in decreasing order of
boiling point.
(4)
113. (a)
Compounds of formula C4H7Cl exhibits both geometrical and optical isomerism.
(i)
Explain why C4H7Cl shows geometrical isomerism.
(1)
(ii)
Draw the cis and trans isomers of C4H7Cl.
(iii)
Draw the structural formula of C4H7Cl that shows only optical isomerism. Show
the chiral carbon atom with ― * ‖.
(2)
b)
Explain why 1,2-dichlorocyclopropane has cis and trans isomers. Draw the structural
formulas of the two isomers.
(3)
114. On being reacted separately with HBr, 2-methylbut-1-ene and 2-methylbut-2-ene produce the
same major product but different minor products.
(a)
Draw the structural formula of the major product and explain why it is formed in terms of
the stability and structure of the organic intermediate.
(4)
(b) Draw the structural formulas of the two minor products.
(2)
18
115. (a)
Explain why aminoethane (ethylamine) is more basic than ammonia.
(2)
(b)
Explain why 2,4,6-trinitrophenol is more acidic than phenol.
(2)
116. (a)
State two characteristics of a homologous series.
(2)
(b) Describe a chemical test to distinguish between alkanes and alkenes, giving the result in
each case.
(3)
117. (a)
Identify the reagents used in the nitration of benzene.
(b) Write an equation or equations to show the formation of the species NO2+ from these
reagents.
(c)
Give the mechanism for the nitration of benzene. Use curly arrows to represent the
movement of electron pairs.
(d) Predict the structures of the products of the (mono) nitration of methylbenzene
methylbenzene (two products)
nitrobenzene (one product)
(3)
(e)
Explain why the nitration of methylbenzene is faster than the nitration of benzene.
(2)
(f)
Identify the reagent and catalyst used to convert benzene into methylbenzene.
(2)
118. (a)
There are geometrical isomers of the cyclic compound C4H6Cl2. Draw the structural
formula of two isomers and explain why these two isomers exist.
cis-isomer
trans-isomer
(3)
(b) (i)
Draw the structural formulas of two isomers of but-2-ene-1,4-dioic acid.
(2)
(ii)
State and explain which isomer will have a lower melting point.
(2)
(iii) Describe how the two isomers can be distinguished by a chemical test.
(c)
Consider the following compounds:
1-chloropentane, 2-chloropentane, 3-chloropentane
(i)
Identify the compound which exhibits optical isomerism and draw the structures of
the two isomers.
ii)
Describe how these two isomers can be distinguished experimentally. (1)
119. Compounds with the molecular formula C3H4Cl2 exist as several structural isomers, some of
which are cyclic. Some of these structural isomers exist as geometric isomers.
(a)
Explain why geometrical isomerism is possible in the non-cyclic isomers.
19
(b) Draw the structure of a non-cyclic structural isomer that does not exist as geometric
isomers, and explain why geometrical isomerism is not possible in this compound.
(c)
1,3-Dichloropropene exists as geometric isomers. Draw and label the structures of its cis
and trans isomers.
(2)
(d)
Draw structures to show the two geometric isomers of 1,2-dichlorocyclopropane.
(2)
120. Methylbenzene and chlorine react together in a 1:1 ratio in the presence of iron(III) chloride.
(a)
State the type of mechanism of this reaction and write an equation to show how iron(III)
chloride generates the attacking species.
(2)
(b)
Use equations to explain the mechanism of this reaction, representing the movement of
electron pairs by curly arrows.
(4)
121. The following transition state is formed during the reaction of a halogenoalkane with aqueous
sodium hydroxide:
CH3
H 3C
HO
C
Br
H
(a)
Deduce the structure of the halogenoalkane. Classify it as primary, secondary or tertiary,
giving a reason for your choice.
(2)
(b)
The mechanism of this reaction is described as SN2. Explain what is meant by the
symbols in SN2. Predict a rate expression for this reaction.
(3)
(c)
The same halogenoalkane reacts with sodium hydroxide by an SN1 mechanism. Deduce
the structure of the intermediate formed in this reaction.
(1)
122. This question is about structural isomers and stereoisomers with the molecular formula
C4H6Cl2.
(a)
The compound 1,3-dichlorobut-1-ene can be used to illustrate two types of
stereoisomerism. For each type of stereoisomerism, draw two structures to show the
relationship between the two.
two geometrical isomers
two optical isomers
(4)
(b) Explain the term racemic mixture.
(1)
(c)
Outline how the two optical isomers of 1,3-dichlorobut-1-ene can be distinguished from
20
each other and from a racemic mixture.
(3)
(d) 1,3-dichlorocyclobutane exists as geometrical isomers. Draw the 3-dimensional structures
of these isomers.
(2)
123. But-1-ene undergoes an electrophilic addition reaction with iodine chloride, ICl. The
major product of this reaction is 2-chloro-1-iodobutane.
(a)
Show the mechanism of this reaction, using curly arrows to represent the movement of
electron pairs.
(b)
Deduce the name of the minor product of this reaction and explain why only a small
amount of it is formed.
(4)
124. (a)
List two characteristics of a homologous series.
(1)
(b) Ethanol and ethanoic acid can be distinguished by their melting points. State and explain
which of the two compounds will have a higher melting point.
(2)
(c)
Draw the three isomers containing the alcohol functional group of formula C4H9OH.
125. The molecular formula, C3H4Cl2 represents several isomeric compounds. Some isomers are
cyclic and some are unsaturated.
(a)
Draw the structures of two cyclic compounds that are structural isomers and state the
names of both isomers.
(2)
b)
Two of the non-cyclic compounds have geometrical isomers. Draw the structures of these
compounds and their geometrical isomers.
(2)
126. When hydrogen cyanide reacts with an aldehyde or a ketone the product molecule has one more
carbon atom.
(a)
Write an equation to show the addition of hydrogen cyanide to propanone.
b)
Describe, using curly arrows, a mechanism for the reaction of hydrogen cyanide with
propanone.
(c)
Write an equation for the acid hydrolysis of this product. State the two functional groups
in the organic product.
(2)
127. The structure of benzene can be represented in two ways.
structure A
(a)
structure B
Use information from Table 9 of the Data Booklet to explain why structure B is used in
21
preference to structure A.
(2)
(b) The enthalpy changes for the hydrogenation of cyclohexene and benzene are as follows.
(i)
C6H10 + H2 → C6H12
∆Hο = –120 kJ mol–1
C6H6 + 3H2 →C6H12
∆Hο = –210 kJ mol–1
Explain how this information can be used to support the statement that structure B
is more stable than structure A.
(2)
(ii) State what the circle in structure B represents.
(1)
128. Cyclohexanone can react with 2,4-dinitrophenylhydrazine in aqueous solution.
(a)
State the type of reaction that takes place.
(1)
(b) Complete the equation for this reaction using structural formulas for the products.
H
H2 N
N
O
NO 2
+
NO 2
(2)
(c)
State why the product from this particular reaction can be used to confirm that the
reactant was cyclohexanone and not any other carbonyl compound.
(1)
129. Explain how the presence of the –NO2 group on a benzene ring affects the rate of further
substitution.
22
130. A 131.
D 132. C133. D 134. C 135. C 136. D 137. B 138. B139. C 140. B141. D
142. B 143.
C 144. A 145. A 146. B147. B 148. C149. D150. A151. C152. B 153. C
154. D155.D156.B157.A158.B159.D160.C 161.D 162.C 163.A 164.D 165.D 166.A 167.A
168. C 169.A170.B 171.B 172.C 173.A 174.D 175.B 176.A 177.D 178.B 179.B180.B
181. C 182.A 183.B 184.A 185.D 186.B 187.D 188.C189.
(i) butane;
C4H10(g) + 132 O2(g)  4CO2(g) + 5H2O(l);
(ignore state symbols, accept balancing using 13O2 )
[1] for all formulas and [1] for balancing equation.
CO produced;
CO is poisonous/combines with hemoglobin/OWTTE;
or
C;
which causes respiratory problems;
(ii)
5
add Br2 (water);
valid test needed to score further marks.
A – no effect;
B – would decolorise Br2 (do not accept discolour);
(iii)
3
CH3CH==CHCH3 + HBr  CH3CHBrCH2CH3;
[1] for HBr in balanced equation, [1] for structure of product.
3
addition;
190. (i)
(ii)
191. (i)
(ii)
192. (a)
(b)
CH3OH + HCOOH  HCOOCH3 + H2O
[1] for both reactants and [1] for both products (accept
C2H4O2) methyl methanoate;
3
ethanoic acid;
1
CH2OH COOH
alcohol (accept hydroxy(l));
carboxylic acid;
Last two marks dependent on correct monomer or reasonable
attempt at identifying the monomer.
3
condensation;
eliminates H2O/a small molecule is eliminated;
2
change/replacement of atom/group (in molecule);
by species with a non-bonding/lone pair of electrons/attracted to electron
deficient part of molecule (OWTTE)/Lewis base;
2
(i)
CH 3
CH 2
CH 2
CH 2 Br / CH 2
CH
CH 3
(ii)
CH3–––CH2–––CHBr–––CH3
CH 2 Br
1
1
(iii)
23
CH 3
CH 3
C
Br
CH 3
Position of Br must be clearly shown
In (i), (ii) and (iii), all C—C bonds must be shown. Do not
penalize missing H atoms.
193. (i)
1
esterification/condensation;
CH3COOH + C2H5OH
CH3COO C2H5 + H2O
Accept product: ethyl ethanoate/ethyl acetate;
structure:
O
O
accept ;
C
CH 3
4
C2H5
O
C
CH 3
O
C2H5
Do not accept CH3COOC2H4.
(ii) catalyst;
lowers Ea (by providing an alternate pathway);
2
(iii) flavouring agents/in plasticisers/in solvents/in perfumes/making
aspirin
194. (i)
(ii)
II reacts with Br2
II is an alkene/has unsaturated R group/C
only saturated R groups;
CH
2
CH 2
)
(
CH 2
O
C
CHO
)
O
accept
2
C4H10 : non-polar, only van der Waals’ forces that cannot replace/
interact with H–bonding in water;
C2H5Cl : only slightly polar/not capable of H–bonding with water;
2
(CH3)2CO: highly polar/forms H–bonding with water;
C3H7OH : forms H–bonding with water (as H is bonded to O);
2
H 3C
H
+
O
C
CN
H
[1]
H+
CH 3
–
NC
C
O–
H
OR :CN –
[1]
[1]
Mark for intermediate.
196. (a)
CH
O
H
(ii)
C present, I contains
addition polymerization;
(
195. (i)
1
CH 3
NC
C
OH
H
[1]
Do not penalise if CN is the
wrong way round.
4
24
(b)
(i)
CH3
CH3
C
C
OH
HOOC
HO
H
H
COOH
[1]
[1]
Allow [1] if the structures are correct but it is not clear that
they are mirror images.
(ii) (identical) except with other optically active compounds;
(identical) except that they rotate the plane of plane-polarised
light in opposite directions;
197. (a)
ethene;
2
2
H
H
C
(b)
2
/ CH2
C
CH2
H
H
A addition/hydration;
H2O/water/steam;
B oxidation;
acidified K2Cr2O7
Accept acidified KMnO4.
4
(c)
H
H
C
C
H
/ CH2
CHCl
Cl
Cl H
H
C
C
H
H
Cl / CH 2 ClCH 2 Cl ;
The compound formed directly may be circled or indicated by some
other means. Accept any other structure showing a Cl atom on each C atom.
3
(d)
H
(e)
(f)
H
Cl
C
C
H
H
Cl / CH3 CHCl 2 ;
addition across a double bond occurs at both C atoms/OWTTE;
If 1,1-dichloroethane is given in (c) accept 1,2-dichloroethane
as the isomer as ECF but Award [1] max;
2
addition polymer;
2
H
H
H
H
H
H
C
C
C
C
C
C
H H H H
condensation polymer;
H
H
/
( CH2
allow
CH2 )3 ;
( CH2 ) 3
25
198. (i)
polyesters;
polyamides;
3
optical isomers rotate the plane of polarized light
(in opposite directions);
1
(ii)
1
H
H
O
N
C* C
;
CH 3
The chiral centre may be indicated by an asterisk, circle,
highlight, etc.
(iii)
H
C
NH
H
CO
C
CH 3
CH 3
CO
NH
Award [1] for one 3-D structure and [1] for showing that the second
structure is a mirror image of the first one.
2
199. (a)
substitution;
nucleophilic;
bimolecular/two species in rate-determing or slowest step;
Do not accept second order.
Three correct [2] , two correct [1] , one correct [0].
2 max
(b)
(c)
aminoethane/ethylamine;
1
curly arrow from N of NH3 to C joined to Br;
curly arrow from C—Br bond to Br;
central C of transition state joined to CH3, H, H, Br and NH3;
transition state with no charge and with --- bonds to NH3 and Br;
Ignore products.
H
200. (i)
H
(ii)
(iii)
(iv)
201. (i)
H
C
CH2CHCl/CH2 = CHCl/
C
;
H
C
C
H
Cl
1
Cl
addition (polymerization);
(carbon-carbon) double bond/unsaturation/OWTTE;
H
4
;
monomers have smaller molecules/surface area than polymers;
with weaker intermolecular/Van der Waals’ forces;
Accept opposite argument for polymers.
2
1
2
COOH (CH2)4COOH;
26
NH2(CH2)6NH2;
Accept more detailed formulas.
Award [1] for correct functional groups for both compounds
but wrong formulas.
(ii)
condensation (polymerization);
two functional groups on each monomer/OWTTE;
2
2
(iii)
O
H
C
N
accept —CONH—
peptide/amide;
water/H2O;
3
(iv) rotate the plane of (plane-)polarized light; asymmetric carbon atom
/chiral centre;
H
H
C
H2 N
3
COOH
HOOC
CH 3
C
CH 3
NH 2
(v)
glycine/Gly/H2NCH2COOH;
1
(vi)
flavouring agents/plasticizers/solvents/perfumes; ethanol;
methanoic acid;
3
202. (CH3)3CI  (CH3)3C+ + I;
(CH3)C+ + OH  (CH3)3COH;
Do not allow SN 2 reaction.
2
203. CH3CH(OH)CH2CH3;
Accept more detailed formula.
butan-2-ol;
Accept 2-butanol.
ECF for correct name of another C4 alcohol.
contains a chiral/asymmetric carbon atom/four different groups around one
carbon atom;
(plane of) plane-polarized light rotated in opposite directions;
204. (a)
replacement of atom/group (in a molecule)/OWTTE;
Do not accept substitution.
by a species with a lone pair of electrons/species attracted to an
electron-deficient carbon atom;
4
2
(b) correct structure of (CH3)3CBr;
curly arrow showing CBr bond fission;
correct structure of (CH3)3C+;
curly arrow showing attack by OH on correct C atom;
correct structure of (CH3)3COH;
Award [1] each for any four.
(c)
4
correct structure of CH3CH2CH2CH2Br;
curly arrow showing CBr bond fission;
27
correct structure of transition state showing charge and all bonds;
curly arrow showing attack by OH on correct C atom;
correct structure of CH3CH2CH2CH2OH;
Award [1] each for any four.
4
(d) secondary
CH3CHBrCH2CH3;
2-bromobutane;
other primary
(CH3)2CHCH2Br;
1-bromo-2-methylpropane;
205. (a)
Nucleophillic addition reaction;
5
CH 3
CH 3
H 3C
H
4
+
–
NC
O
C
CN
H
OR :CN –
[1]
O–
C
[1]
H+
NC
C
H
H
[1]
[1]
Intermediate.
OH
Product
(b)
1
CH 3
H
OH ;
C
COOH
206. methyl methanoate;
HCOOCH3;
Accept other correct alternative.
207. (i)
(SN2 mechanism)
3
Cl
CH 2
CH 2
CH 2
CH 3
;
–
HO
curly arrow must start from O or negative charge
Cl
HO
CH 2
CH2
CH 2
CH 3
;
Intermediate structure showing overall negative charge and
partial bonds.
Accept negative charge to be indicated as delocalised between
the HO-CH2-Cl.
28
 HO  CH2CH2CH2CH3 + Cl;
(ii)
(SN1 mechanism)
2
CH 3
CH 3
C
CH3
CH 3
Cl
+ Cl -
C
;
CH 3
CH 3
formation of carbocation / loss of Cl -
CH 3
CH 3
CH 3
+ OH -
C
CH 3
C
OH
;
CH 3
CH 3
carbocation + OH -
208. butan-1-ol:
butanal;
butanoic acid;
butan-2-ol:
butanone;
2 methylpropan-2-ol:
no oxidation;
Also accept correct structures. Where both name and structure
given structure must be correct and name largely correct.
209. (a)
(b)
UV light/sunlight (present);
1
Throughout accept radical with or without •
initiation reaction(s):
Cl2  2Cl•;
1
propagation reactions:
Cl• + CH3CH3  CH3CH2• + HCl;
CH3CH2• + Cl2  CH3CH2Cl + Cl•;
2
termination reactions:
CH3CH2• + Cl•  CH3CH2Cl;
2Cl•  Cl2;
2CH3CH2•  CH3CH2CH2CH3;
Award [1] for any termination reaction.
If initiation, propagation, termination not labelled or
incorrectly labelled award [3] max.
1
210.
H
higher;
H
H
C
C
C
C
H
H
O
H
H
H;
29
211. (the molecule contains a) chiral/asymmetric carbon atom/carbon atom with four
different groups;
polarized light passed through;
(plane of polarization) rotated in opposite/different directions;
212. (i)
(ii)
213. (a)
HOCH2CH2OH;
HOOCC6H4COOH;
2
reactants have two functional groups/OWTTE;
1
symmetrical/planar/hexagonal structure;
delocalisation of electrons/resonance hybrid;
C-C bond length same/C-C bond strength the same;
angle 120;
carbon is sp2 hybridized;
Award [1] each for any four points.
(b) 360 kJ mol1;
(c)
214. (i)
(ii)
4
1
benzene is more stable because of delocalisation/does not contain three
double bonds;
1
C4H8 + Br2  C4H8Br2;
Equation scores [1].
CH3CHBrCHBrCH3;
Accept more detailed formula.
2
addition;
1
215. 360 (kJ mol1);
benzene more stable than structure with (three) double bonds/benzene
contains delocalized electrons;
Do not accept delocalized bonds.
2
216. propan-2-ol;
Accept 2-propanol.
oxidation/redox;
(potassium/sodium) dichromate(VI)/potassium manganate(VII);
Accept just dichromate, permanganate, KMnO4 , Mn O4 , K2Cr2O7, Cr2 O72 .
(sulfuric) acid;
heat under reflux;
217. (i)
CH2 CH3
HO
C
H
Br
CH3
all five groups around C correct;
negative charge and dotted lines to OH and Br correct;
Do not award 2nd mark if bond from OH (i.e. OH-----).
(ii)
2
CH3CH2CH(CH3)Br  CH3CH2CH(CH3)+ + Br;
CH3CH2CH(CH3)+ + OH  CH3CH2CH(CH3)OH;
Accept C4H9 instead of CH3CH2CH(CH3) throughout.
2
30
218. (i)
react with 2,4-dinitrophenylhydrazine solution;
determine the melting points of the product;
2
(ii)
NO2
H2N
HN
;
NO2
NO2
CH3CH 2CH 2
C
N
;
HN
H3C
NO2
2
219.
CH3
CN
:CN –
O–

CH3 CH2CH2
C+

CH3CH2 CH2
C
CN
H+
O–
CH3CH2CH2
CH3
Award [1] for each curly arrow and [1] for the final product.
curly arrow from C of cyanide ion to C of carbonyl group;
curly arrow from C=O bond to O;
curly arrow from O to H+;
C
OH
CH3
4
220. (a)
H
H
C
C
;
H
H
Allow CH2=CH2.
a hydrocarbon that contains at least one C=C (or CC)/carbon-carbon
double bond (or triple bond)/carbon to carbon multiple bond;
Do not accept just ―double bond‖.
(b) C2H4 + H2O  C2H5OH;
addition/hydration reaction;
(c)
2
2
heat under reflux;
EITHER
potassium dichromate(VI)/K2Cr2O7/Cr2O72–and acidified/H+;
orange to green;
OR
potassium permanganate/manganate(VII)/KMnO4/MnO4– and
31
acidified/H+;
purple to colourless;
Penalize wrong oxidation state, but not missing oxidation state.
ethanoic acid;
(d)
221. (i)
4
CH3COOH + C2H5OH  CH3COOCH2CH3 + H2O;
Accept CH3COOC2H5
sulfuric acid/H2SO4/(ortho)phosphoric acid/H3PO4;
ethyl ethanoate;
solvent/flavouring/perfumes/plasticizers;.
4
same molecular formula but different structural formula/
arrangement of atom within a molecule/OWTTE;
1
(ii)
2
H
CH 3 COCH 3
H
O
C
C
H
C
H
H
CH 3CH 2CHO
H
;
H
H
C
C
H
H
C
;
O
H
H
Accept unsaturated alcohol and cyclic alcohol as alternative
answers. If more than two correct isomers given  no penalty 
but a third incorrect structure cancels a correct one. i.e. two
correct, one incorrect equals [1].
(iii)
isomers that can rotate plane polarized light in opposite directions;
Do not accept bend, reflect plane-polarized light.
H
H
H
H
H
C
H
C
C
C* H
H
H
O
H
H
H
H
H
C
C
C
H
H
OH H
* C
H
H
H
C 2H 5
C*
CH 3
other correct structure;
OH
Penalize missing bonds/hydrogens.
correct identification of chiral carbon (*);
222. (a)
a hydrocarbon that contains at least one C=C (or CC)/carbon-carbon
double bond (or triple bond)/carbon to carbon multiple bond;
Do not accept just ―double bond‖.
3
1
32
(b)
(c)
C2H4 + H2O  C2H5OH;
addition/hydration reaction;
2
heat under reflux;
EITHER
potassium dichromate(VI)/K2Cr2O7 / Cr2O72– and acidified/H+;
orange to green;
OR
potassium permanganate/manganate(VII)/KMnO4 / MnO4– and acidified/H+;
purple to colourless;
Penalize wrong oxidation state, but not missing oxidation state.
ethanoic acid;
4
(d) CH3COOH + C2H5OH
CH3COOCH2CH3 + H2O;
accept equations including H+.
Reversible arrow not required for the mark.
223. (i)
sulfuric acid/H2SO4/(ortho)phosphoric acid/H3PO4;
Z – ethyl ethanoate;
solvent/flavouring/perfumes/plasticizers;
4
same molecular formula but different structural formulae/arrangement
of atoms within a molecule/OWTTE;
1
H
CH 3 COCH 3
H
C
O
C
H;
C
H
H
CH 3 CH 2CHO
(ii)
H
H
H
C
C
H
H
H
H
C
;
O
2
Accept unsaturated alcohol and cyclic alcohol as alternative
answers.
If more than two correct isomers given  no penalty  but a
third incorrect structure cancels a correct one. i.e. two correct,
one incorrect equals [1].
(iii) isomers that can rotate plane polarized light in opposite directions;
Accept two molecules/compounds, which are mirror images of
each other.
Do not accept bend, reflect plane-polarized
33
H
H
H
H
H
C
H
C
C
C* H
H
H
O
H
H
H
H
H
C
C
C* C
H
H
OH H
H
H
H
C*
C 2H5
light.
CH 3
other correct structure;
OH
correct identification of chiral carbon (*);
3
(iv)
H
H
H
H
H
C
C
C
C
H
H
H
H
H
CH 3 H
C
C
C
H
H
H
H
OH
OH
H
H
C
H
H
H
H
C
C
C
H
OH H
H ;
Award [1] mark for 3 structures
H
H
C
H
2-methylpropan -2-ol /
H
H
H
C
C
C
H
OH H
H ;
2
Penalize [1] mark for the omission of H in (i) to (iv).
224. ultraviolet light causes ClCl bond to split;
Cl2  2Cl•;
Cl• + CH3CH3  CH3CH2• + HCl;
CH3CH2• + Cl2  CH3CH2Cl + Cl•
CH3CH2• + Cl•  CH3CH2Cl/other correct termination step;
Penalize missing  symbol once only.
If different alkane used, then deduct [1].
No penalty for not labelling steps, but deduct [1] if any wrongly
labelled.
5
225. (i)
34
O
CH 3
C
CH 2CH 2 CH 3 / CH 3COOCH 2CH 2CH 3 ;
O
1
(ii)
propan-1-ol/1-propanol;
CH3CH2CH2OH;
Accept full structural formula showing all bonds and atoms but
no mark if H atoms missing
ethanoic acid/acetic acid;
CH3COOH;
Accept full structural formula penalize missing Hs only once
ECF from incorrect ester in (i) above
4
226. (i)
H
CH 3
C
CH3
/ CH 3 CH(OH)CH 3 ;
OH
1
Allow bond to HO rather than OH or halfway between the two
(ii)
secondary;
1
(iii)
CH3COCH3/propanone/acetone;
Allow ECF from a different alcohol drawn in (i)
1
SN2 / bimolecular;
1
227. (a)
(b) (i)
(ii)
228. (i)
reaction slower;
neutral/uncharged/less polar/electrons donated less easily in H2O;
2
reaction faster;
less bulky group/reduced steric hindrance;
2
(Empirical formula =) C8H8O3;
H
H
O
O
H C
C
H
O
H
;
H
H
H
Allow double bonds on arene in alternate positions, or allow
delocalized representation (of pi electrons).
(ii) the bond at 0.1373 nm is a double bond and the bond at 0.1424 nm is a
single bond;
in CO2(g) both bonds are double bonds and would have a value
around 0.137 nm;
(iii)
Ester;
Arene/benzene ring;
Alcohol;
Award 2 for any three correct, award [1] for any two correct.
2
2
2
35
Do not accept alkane as a type of functional group in this
molecule.
229. (i)
(ii)
boiling point increases as the number of carbons increases/OWTTE;
Greater Mr and hence greater van der Waals’/London/dispersion forces present; 2
CH4 + Cl2 hv
/ UV
light

 CH3Cl + HCl;
Do not award mark if hv/uv light is not given.
Initiation step:
Cl2 hv
/ UV
light

 2Cl•;
Do not award mark if hv/uv light is not given.
Penalize once only.
Propagation step:
CH4 + Cl• → CH3• + HCl;
CH3• + Cl2 → CH3Cl + Cl•;
Termination step:
Cl• + Cl•  Cl2 or Cl• + CH3•  CH3Cl or CH3• + CH3• → CH3CH3;
Allow fish-hook half-arrow representations i.e. use of
.
Penalize use of full curly arrows once only.
Penalize missing dots on radicals once only.
230. (i)
A. = CH3(CH2)7CHO;
B. = CH3(CH2)7COOH/CH3(CH2)7CO2H;
C. = (CH3)3COH;
D. = (CH3)2CO;
E. = BrCH2CH2Br;
Allow correct structural formulas.
5
5
(ii) addition;
/-(CH2-CH2)3-/-(CH2)6-;
2
231. (i)
OH
OH
C
CH3 CH2
H
CH3
H
CH3
C
CH2 CH 3
2
Award [2] for both tetrahedral structures, or [1] if tetrahedral
structure is not clear.
(ii) plane polarized light;
rotation in opposite/different directions;
2
(iii)
36
CH 3
CH 3
C
C
H
H
CH 3
H
C
C
;
CH 3
H
(iv)
;
2
curly arrow showing attack by –OH on end H;
curly arrow showing C–Br bond fission;
curly arrow showing formation of double bond;
H2O and Br– shown as products;
Award [1] each for any three.
If but-2-ene formed, award [2 max].
3 max
232. CH3OH + HCOOH  HCOOCH3 + H2O
Award [1] for both reactants and [1] for both products (accept
C2H4O2).
methyl methanoate;
233. (a)
3
C6H6 + CH3CH2Cl  C6H5CH2CH3 + HCl;
CH3CH2Cl + AlCl3  CH3CH2+ + AlCl4–;
(i)
+
CH 2 CH 3
5
CH 2 CH 3
CH 2 CH 3
H
+
+
[1] for arrow
[1] for intermediate
CH 2 CH 3
CH 2 CH 3
+
H
CH 2 CH 3
H
+ H+
+
[1] for arrow
(ii) free radical substitution;
(b)
(i)
1
one correct structure;
second structure clearly a mirror image;
e.g.
Cl
C6 H 5
C6 H 5
C
C
H
CH 3
H
CH 3
Cl
2
(ii) light in which all waves/vibrations are in one plane;
plane-polarized light passed through each isomer (solution);
plane of polarization rotates;
37
(iii)
(c)
234. (a)
(b)
in opposite directions for each isomer;
4
equal amounts of each isomer were formed/racemic mixture formed;
optical activities/rotations cancelled out;
2
chlorobenzene;
nucleophile/OH– repelled by delocalized electrons/carbon atom being
attacked is less electron-deficient/carbon-chlorine bond is stronger;
all C—C bonds in benzene or structure B are 0.139 (nm) (long) or the
same length; structure A would have C—C bond lengths of 0.154 and
0.134 (nm)/benzene does not have C—C bond lengths of 0.154
or 0.134 (nm)/different bond lengths;
If no reference to carbon-carbon bonds, award [1 mark].
value for cyclohexene/–120 is for (hydrogenation of) one C ==C bond;
structure A/Kekulé structure would have value of (about) –360 (kJ mol–1);
150/difference between –360 and –210 represents greater stability of
benzene/structure B;
2
2
3
235. CH3CH2NH2 + H2O → CH3CH2NH3+ + OH–;
Accept → .
(ethylamine) more basic/higher basicity;
because of presence of electron-releasing (ethyl or alkyl) group;
N more electron-rich/attracts H+ (or from H from H2O) more easily;
236. (a)
4
(F)
CH 3
Cl
;
(G)
CH 3
;
2
Cl
Order not important
(b)
(c)
(d)
electrophilic substitution;
1
curly arrow from delocalized electrons to Cl+;
structure of intermediate showing Cl attached to ring, + charge and
the remaining four electrons in benzene ring;
curly arrow showing C–H bond fission and electrons moving into
benzene ring;
3
(J)
(K)
C6H5CH2Cl;
C6H5CHCl2;
38
(L)
(e)
(f)
C6H5CCl3;
Accept versions using hexagon to represent benzene ring.
3
free-radical substitution;
1
Cl2 → 2Cl•;
sunlight/UV light;
Accept heat.
2
C6H5CH2Cl + Cl• → C6H5CHCl• + HCl;
(g)
(h)
C6H5CHCl• + Cl2 → C6H5CHCl2 + Cl•;
2
C6H5CCl2• + Cl• → C6H5CCl3;
1
(i)
methylbenzene is more reactive;
methyl group in methylbenzene is activating/electron-releasing;
and makes the ring more reactive towards electrophiles/NO2+;
237. (a)
3
2
OH
OH
C
H
;
CH 3 CH 2
C
;
H
CH 2 CH 3
CH 3
CH 3
Award [2] for both tetrahedral structures, or
[1] if tetrahedral structure not clear.
(b)
2
CH 3
CH 3
C
C
H
H
CH 3
H
C
C
H
(c)
;
;
CH 3
curly arrow showing attack by – OH on end H;
curly arrow showing C–Br bond fission;
curly arrow showing formation of double bond;
H2O and Br– shown as products;
Award [1] each for any three.
If but-2-ene formed, award [2 max].
3 max
238. (a)
[1]
H
CH 3CH 2 CH 2 C
[1]
H
H
Br
+
–
OH
OH
CH 3CH 2 CH 2 C
H
[1]
Br
CH 3CH 2 CH 2 CH 2 OH
[1]
(+Br – )
suitable diagram with structure of 1-bromobutane;
39
(b)
(c)
two correctly positioned curly arrows;
(second one must start from O or – sign)
transition state structure with partial bonds to OH and Br and a
negative charge;
Correct structure of butan-1-ol;
4
the rate of the reaction doubles;
the rate is proportional to [OH–]/OH– appears in the rate-determining
step/first order with respect to OH–;
2
(1-chlorobutane reaction rate) is slower;
CCl bond is stronger/harder to break.
2
239. (a)
1
H
C
Cl
H
(b)
(c)
Cl2 → 2Cl•
initiation;
Cl• + C6H5CH3 → C6H5CH2• + HCl
propagation;
C6H5CH2• + Cl2 → C6H5CH2Cl + Cl•
propagation;
any correct termination equation
termination
Award [1] for each correct equation.
Award [1] for correct naming throughout.
Ignore ―curly arrows‖.
5
breaks Cl—Cl bond homolytically/produce free radicals;
1
240. (a)
:CN –
[1]
[1]
H3 C
[1]

C
+

O
H+ / H
CN
CN
CN
–
H3 C
H3 C
C
O
H3 C
CH 3
Suitable diagram with
curly arrow showing attack by CN– on carbonyl Cδ+;
curly arrow showing pi bond breaking;
curly arrow from O to H+/H—CN;
structure of product (CH3)2C(OH)CN;
Accept more detailed formula.
(b)
241. (a)
(CH3)2C(CN)OH + H+ + H2O → (CH3)2C(COOH)OH + NH4+;
carboxylic acid and alcohol;
Accept hydroxy(l) instead of alcohol.
same general formula/CnH2n;
formulas of successive members differ by CH2;
similar chemical properties/same functional group;
gradation/gradual change in physical properties;
Award [1] each for any three.
C
CH 3
OH
[1]
4
2
3
(b) but-2-ene;
Accept 2-butene.
40
strongest intermolecular/van der Waals’ forces;
largest (molecular) mass/size/surface area/area of contact;
(c)
CH2CHCH2CH2CH3/CH3CHCHCH2CH3/any correct branched structure;
Accept more detailed formula.
pent-1-ene/pent-2-ene;
Name must match formula.
Accept 1-pentene/2-pentene.
(d)
(e)
(f)
242. (a)
3
2
C4H8 + HBr  CH3CH2CHBrCH3;
Award [1] for all molecular formulas correct and [1] for
correct product structure.
Award [1] for completely correct equation starting with
but-1-ene.
addition;
3
oxidation/redox;
(potassium) dichromate(VI)/ Cr2 O 72 ;
(sulfuric) acid;
distilling off propanal as it is formed;
heating under reflux (to obtain propanoic acid);
5
(propan-1-ol) hydrogen bonding;
(propanal) dipole-dipole attractions;
(propanoic acid) hydrogen bonding;
propanoic acid > propan-1-ol > propanal;
4
(i)
1
no rotation possible due to double bond/ bond;
Accept restricted or hindered rotation.
(ii)
2
H
H
C
Cis
;
C
CH 2Cl
CH 3
H
CH 3
C
trans
C
;
CH 2Cl
H
OR
H
H
C
;
C
CH2CH 3
Cl
Cis
H
Cl
CH 2CH 3
H
trans
;
C
C
OR
CH 3
CH3
C
Cis
C
Cl
H
CH 3
H
C
trans
CH 3
C
Cl
41
(iii)
H
H
C
H
C
;
*C
H
CH 3
Cl
2
Award [1] for the structure and [1] for showing * on the correct
carbon atom.
(b) restricted rotation because CC bond is now part of a cyclic system;
3
CH 2
H
Cl
C
;
C
H
Cl
trans
CH 2
H
H
C
;
C
Cl
Cl
Cis
243. (a)
CH 3
CH 3
C
CH 2
CH 3 ;
Br
tertiary carbocation;
more stable;
due to 3 electron releasing alkyl groups/positive inductive effect;
4
(b)
CH 3
CH2
CH
CH2
CH3 ;
CH
CH 3 ;
Br
CH3
CH3
CH
Br
244. (a)
2
alkyl group is electron releasing/positive inductive effect;
42
electron density on N atom greater;
2
(b) NO2 group is electron withdrawing/negative inductive effect;
negative charge delocalised on the ring;
245. (a)
(b)
2
same general formula;
successive members differ by CH2;
Do not allow elements or just ―they‖.
similar chemical properties;
Allow same/constant.
gradual change in physical properties;
Do not allow change periodically.
same functional group;
Award [1] each for any two.
2
add bromine (water);
alkanes  no change/stays or turns brown;
Allow red-brown or any combination of brown, orange or
yellow.
alkenes  bromine (water) decolorizes;
Do not allow clear or discoloured.
or
add (acidified) KMnO4;
alkanes  no change;
alkenes  KMnO4 decolorizes/brown/black;
246. (a)
3
concentrated HNO3;
concentrated H2SO4;
No penalty for omitting one ―concentrated‖.
Award [1] for both reagents correct but no ―concentrated‖.
2
(b) HNO3 + H2SO4  H2NO3+ + HSO4 and H2NO3+  H2O + NO2+;
Or
HNO3 + H2SO4  H2O + NO2+ +HSO4/HNO3 + 2H2SO4  H3O+ + NO 2
+ 2HSO4;
1
(c)
NO
NO 2

NO 
H
+
;
H
+
Award mark for curly arrow shown correctly.
NO 2
NO
H
+
H
NO2
+
+H ;
+
2
Award mark for curly arrow shown correctly.
(d)
43
CH 3
CH 3
NO 2
and
;
NO 2
Accept correct names.
Award [1] for each.
NO 2
;
NO 2
3
Accept 1,3-dinitrobenzene.
(e)
(f)
247. (a)
CH3 is electron-releasing/has positive inductive effect;
increase attraction between ring and NO2+/OWTTE;
2
chloromethane/CH3Cl;
Accept CH3Br or CH3I.
aluminium chloride/AlCl3/Fe/FeCl3;
2
restricted rotation because CC bond is now part of a cyclic system;
3
H
H
H
H
H
Cl
H
;
H
Cl
H
H
Cl
H
Cl
;
H
H
Award [1] for each correct 3D structure.
If correct structure, but not 3D, or wrongly labelled award [1]
only.
Accept 1,3-disubstituted cyclo compound, or any other correct
isomer.
(b) (i)
2
COOH
HOOC
C
H
(ii)
C
C
;
H
COOH
H
HOOC
C
;
H
cis isomer (has lower melting point than the trans-isomer);
intramolecular hydrogen bonds/weaker intermolecular forces
/less close packing;
2
44
(iii)
(c)
(gentle) heating of a sample of each isomer;
cis isomer readily releases water vapour (forming a cyclic anhydride);
(i)
2
2-chloropentane;
C3H7
C3H7
C
C
;
C1
H
H
C1
CH3
;
CH 3
3
Award [1] for each correct 3D structure.
If correct structures, but not 3D, award [1] only.
(ii)
248. (a)
rotation of the plane polarized light in opposite directions;
restricted/no rotation around double bond/pi bond;
1
1
(b) Accept either of these structures
Cl
H
C
H
C
C
CH 3
Cl
Cl
H
C
;
CH 2Cl
two identical atoms on one side of double bond/interchanging CH3
and H/Cl and CH2Cl makes no difference;
2
(c)
H
H
C
C
Cl
CH 2Cl
H
CH 2 Cl
C
Cl
cis;
C
trans;
H
Award [0] if structure of another isomer drawn.
Award [1] if both structures correct but unlabelled or wrongly
labelled.
Award [1] for each correctly drawn and labelled structure.
(d)
45
Cl
C
H
Cl
H
C
C
;
H
H
H
Cl
C
H
H
C
C
;
Cl
H
2
Award [0] if structure of another isomer drawn.
249. (a)
electrophilic substitution;
FeCl3 + Cl2  FeCl4 + Cl+;
2
(b) (mechanism showing)
curly arrow from circle in benzene ring to attacking Cl+/curly arrow
from one of the three double bonds in the Kekule structure;
intermediate showing 23  56 of circle and + charge;
curly arrow from CH bond into benzene ring;
correct organic product and H+;
Deduct [1] if benzene used instead of methylbenzene.
Deduct [1] if meta-isomer product formed.
CH3
CH3
4
CH3
H
Cl
Cl
+
+
250. (a)
Cl
+
H+
(CH3)2CHBr/more detailed formula;
secondary/2 because two alkyl groups attached to C with Br;
2
(b) nucleophilic substitution;
bimolecular/molecularity of two/two species in rate-determining step;
Accept second order.
(c)
rate = k [(CH3)2CHBr][OH];
No penalty for incorrect halogenoalkane formula.
3
(CH3)2CH+/more detailed formula;
1
251. (a)
46
H
Cl
C
CHClCH3
Cl
C
C
H
C
H
H
CHClCH 3
one correct structural formula;
two distinct isomeric structures shown;
ClHCHC
CH 3
CH 3
C
C
H
CHCHCl
H
Cl
Cl
one correct structural formula shown as 3-D;
two distinct isomeric structures shown;
4
(b) it contains equal amounts/moles of the two optical isomers/enantiomers/
d (dextro/dextrorotatory) and l(levo/levorotatory);
(c)
polarimeter/plane-polarized light;
plane (of polarization) rotated in opposite directions;
no rotation for racemic mixture;
1
3
(d)
H
H
Cl
H
H
H
H
Cl
H
H
Cl
H
Cl
H
H
H
one correct structural formula;
two distinct isomeric structures shown;
2
(mechanism showing)
arrow from C=C double bond towards I;
arrow from I-Cl bond to Cl;
carbocation showing I on first carbon and + charge on second carbon;
arrow from Cl to carbon with + charge and structure of product;
4
(b) 1-chloro-2-iodobutane/2-iodo-1-chlorobutane;
formed via a primary carbocation;
which is less stable than the secondary carbocation;
fewer electron-releasing alkyl groups/positive charge spread out less;
4
252. (a)
253. (a)
one general formula/same general formula;
differ by CH2;
similar chemical properties;
gradual change in physical properties;
Award [1] for any two of the above characteristics.
1
(b) ethanol lower/ethanoic acid higher;
due to larger mass of ethanoic acid/stronger van der Waals’/
London/dispersion forces;
due to stronger hydrogen bonding/2 hydrogen bonds per molecule;
Accept either answer for second mark.
2
47
(c)
2
Allow condensed structural formulas such as
CH3CH2CH2CH2OH.
Award [2] for all three correct isomers, [1] for any two correct
isomers.
254. (a)
Cl
Cl
and 1,1 dichlorocyclopropane;
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
(cis- or trans-) 1,2 dichlorocyclopropane;
Award point for the correct name corresponding to the related
isomer.
Accept diagrams that do not display 3 dimensional structure.
Award [1 max] for correct structures only, without the
corresponding names.
2
(b)
Cl
Cl
CH 3
Cl
and
H
Cl
Cl
H
CH 2 Cl
Cl
CH 3
H
and
H
255. (a)
H
H
(CH3)2CO + HCN  (CH3)2C(OH)CN;
CH 2 Cl
2
1
(b)
48
:CN –
H3C
H+
CN
H3C
C
CN
:
+
–
C O
O
–
H3C
H3C
CH 3
Suitable diagram with
curly arrow showing attack by :CN– on carbonyl Cδ+;
curly arrow showing pi bond breaking;
curly arrow from :O to H+;
structure of product
Accept more detailed formula.
(c)
256. (a)
(b)
C
CH 3
(CH3)2C(OH)CN + H+ + 2H2O  (CH3)2C(OH)COOH + NH4+;
carboxylic acid and alcohol;
Accept hydroxy(l) instead of alcohol.
all C—C bonds in benzene or structure B are 0.139 (nm) (long)/the
same length;
structure A would have C—C bond lengths of 0.154 and 0.134 (nm)/
benzene does not have C—C bond lengths of 0.154 or 0.134 (nm)/
different bond lengths;
If no reference to carbon-carbon bonds, award [1].
(i)
structure A would have value of (about) –360 (kJ mol–1);
150 (kJ mol–1)/difference between –360 and –210 represents
greater stability of benzene/structure B;
(ii) delocalized electrons;
257. (a)
OH
4
2
2
2
1
addition-elimination/condensation;
1
(b)
H
N
N
NO2
+ H 2 O;
NO2
Award [1] for correct structural formula of the organic product
and [1] for water.
(c) the (crystalline) solid has a characteristic melting point;
258. –NO2 is deactivating;
due to its overall electron withdrawing capacity;
which destabilises the carbocation intermediate;
and causes it to form more slowly;
2
1
4
49