Topic 11
Organic Chemistry
11.1
Alkanes, Alkenes, Isomerism and other Functional Groups
SL/HL
1.Which of the following pairs represent members of an homologous series?
A.
C2H4 and C2H6
B.
C2H5Cl and C2H4Cl2
C.
CH3OCH3 and CH3CH2OH
D.
C3H7COOH and C4H9COOH
2. Which names are correct for the following isomers of C6H14?
2-methylpentane
2ethyl-2-methylpropane
2,3-dimethylbutane
A.
I only
B.
I and II only
C.
I and III only
D.
I,II and III
;
3. How many different structural isomers have the formula C4H9C1?
A.
2
B.
3
C.
4
D.
5
4. How many different isomers have the formula C4H10 ?
A.
1
B.
2
C.
3
D.
4
5. Which formula represents an amide?
A.
CH3CH2NH2
B.
CH3CH2N(CH3)2
C.
H2NCH2CO2H
D.
CH3CONH2
6.Which of the following is an amine?
A.
CH3CH2NH2
B.
CH3CONH2
C.
-[CH2CONHCH2CO]n_
D.
CH3CH2C ≡ N
7. Give an equation for the complete combustion of methane, CH 4. Identify two products
formed by the incomplete combustion of methane and identify one harmful effect caused by one
of the products.
(i)
List three characteristics of an homologous series, and explain the term functional group.
(ii) Draw the four structures of alcohols of formula C 4H9OH
8. The plastic PVC, poly(chloroethene), is made from the monomer chloroethene, C2H3C1, by a
polymerization reaction.
(i)
Draw the structural formula of chloroethene.
(ii)
State the type of polymerization reaction that occurs to make poly(chloroethene) and
identify the structural feature needed in the monomer.
(iii)
Draw the structure of the repeating unit of poly (chloroethene).
(iv)
Explain why monomers are often gases or volatile liquids, whereas polymers are solids.
[1]
[2]
[1]
[2]
Topic 11
Organic Chemistry
11.2
Physical Properties of Functional Groups
SL/HL
1. When the compounds below are listed in order of decreasing boiling point (highest to lowest) what is the
correct order?
1.
2.
fluoroethane
ethanol
ethane
2.
3.
A.
4,3,1,2
B.
4,3,2,1
C.
3,4,1,2
D.
2,1,3,4
Which substance dissolves in water to give a neutral solution?
A.
CH3COOH
B.
CH3COONa
C.
CH3CH2NH2
D.
CH3CONH2
Which of the following is expected to be a gas at 25° C?
3.
4.
acid
ethanoic
4.
Which compound is the most soluble in water?
A.
B
C.
D.
Methane
Propane
Propan-1-ol
Pentan-1-ol
5. Which one of the following compounds is optically active?
A.
CH3CH2CH2CH2NH2
B.
CH3CH2CHCH3
NH
C.
CH3CH2NCH2CH3
H
D.
CH3CH2NCH3
CH3
6.Which of the following compounds is optically active?
A.
HO - CH2 - COOH
B.
H3C - CH - COOH
OH
C.
H3C - CH - COOH
CH3
D.
CH3
H3C - C - COOH
Cl
7.Which compound can exist as optical isomers?
A.
H2NCH2COOH
B.
CH2C1CH2C1
C.
CH3CHBrI
D.
HCOOCH3
8. 0.1 mol dm-3 aqueous solutions of these organic compounds were prepared. When these
solutions are arranged in order of increasing pH (lowest pH first), what is the correct order?
I.
CH3CH2CH2OH
II.
CH3CH2CH2NH2
III.
CH3CH2COOH
A.
I<II<III
B.
III<I<II
C.
II<III<I
D.
III<II<I
9. Statement (S): Solubility of alkanols in water decreases with increase in Mr.
Explanation (E): The relative proportion of the hydrocarbon part in alkanol increases with increasing Mr.
A.
Both S and E are true.
B.
Both S and E are false.
C.
false.
S is true but E is
D.
S is false but E is true.
10. (a) State and explain the trend in boiling points of the first 10 members of the alkene series.
[3]
(b) Explain why the boiling points of ethanol and ethanoic acid are considerably higher than the
boiling point of ethanal.
[3]
11. Explain why alkanoic acids are more acidic than alkanols.
12.
[2]
Discuss the factors which affect the boiling points of covalently bonded compounds by
reference to the following pairs of organic substances, whose boiling points are given:
• ethane (184 K) and butane (273 K);
• ethane ( 184 K) and bromoethane (311 K);
• bromoethane (311 K) and ethanol (352 K).
[6]
Topic 11
Organic Chemistry
Addition Reactions of Alkenes and Oxidation of Alcohols
1.
11.3
SL/HL
Which chemical is most likely to be a starting material for a common polymer?
A.
CH3CH2CH3
B.
CH3CH2OH
C.
CH3CHCH2
D.
What will be formed when CH2 = CH2 reacts with Br2 in the dark?
A.
CH2Br —CH2Br
B.
CH3—CHBr2
C.
CH 2 =CHBr + HBr
D.
CHBr = CHBr + H2
3. What is the final product formed when ethanol, CH3CH2OH is reacted with acidified potassium dichromate(VI)?
A.
ethanal
B.
ethane
C.
ethanoic acid
D.
ethene
4. Which compound will undergo oxidation when treated with acidified potassium dichromate(VI)?
A.
CH3CH2CHO
B.
CH3COCH3
C.
CH3COOH
D.
(CH3)3COH
5. Polyunsaturated oils contain many C = C bonds and react with hydrogen to yield fats.
Using the simplified structure of an oil provided below, give the formula of the product
formed by reacting this oil with excess hydrogen, and identify this type of reaction.
[2]
6.
Under certain conditions ethene can be converted to ethanol.
(i)
Give a chemical test to identify ethene and state what would be observed.
(ii)
Give a balanced equation for the reaction to form ethanol from ethene.
(iii)
State the conditions necessary for the reaction in (ii).
[4]
7. Propan-1-ol, in the presence of a small amount of oxidising agent, forms compound X, and
when refluxed with an excess of oxidising agent, forms compound Y.
(i)
Identify a suitable oxidising agent and state the colour change.
[2]
(ii)
Draw the structural formulas of both compound X and compound Y.
[2]
Topic 11
Organic Chemistry
11.4
Condensation Reactions and Condensation Polymerisation
SL/HL
1. What is the name of the compound CH3CH2CH2COOCH3 ?
A.
Butyl methanoate
B.
Methyl butanoate
C.
Methyl propanoate
D.
Pentanone
2.
From which two chemicals could this compound be synthesised?
A.
butanoic acid and pentan-1-ol
B.
butanoic acid and butan-1-ol
C.
butanal and pentan-1-ol
D.
pentanoic acid and butan-1-ol
CH3OH + CH3CH2COOH → CH3CH2COOCH3 + H2O
3.
The forward reaction represented by the equation above is
A.
addition.
B.
esterification.
C.
hydrolysis.
D.
neutralisation.
4. Consider the following reaction:
heat
CH3COOH + NH3→ CH3COONH4 → CH3CONH2
What will be the final product if aminoethane (ethylamine) is used instead of NH3 ?
A.
CH3CONHCH2CH3
B.
CH3CONHCH3
C.
CH3CONH 2
D.
CH3CONH2CH2CH3
j
5. When ethanol is warmed with ethanoic acid in the presence of an acid catalyst a new product is
formed.
(a)
Write the balanced equation for the reaction that takes place using the structural
formulas of the organic reactants and products.
[3]
(b) State how the organic product may be distinguished from the reactants and to which
homologous series it belongs.
[2]
(c) State two reasons why concentrated sulfuric acid is used.
[2]
(d) State and explain how the solubility of the product in water compares with the
solubililty of the two reactants in water.
[2]
6. (i) Draw the structural formula of methyl methanoate. State the conditions and the starting
materials for the preparation of methyl methanoate in the laboratory. Write a balanced
chemical equation for the reaction.
[5]
(ii) Draw the structural formula of an isomer of methyl methanoate. State two physical
properties and one chemical property that would be different for the two compounds.
State how each of these properties differ for the two compounds.
[5]
7 (a)
(b)
the
Name the two functional groups attached to the benzene ring in the following compound:
(i)
The above compound undergoes polymerisation.
[2]
Write the structural formula of
organic product formed when two molecules of this compound react with one another.
[2]
(ii)
What name is given to the links between the rings in the polymer formed from this
compound?
[I]
(iii)
Give the name or formula of the other substance that is formed in the polymerisation
reaction.
(iv)
What type of polymerisation reaction is this?
[1]
[1]
Topic 11
Organic Chemistry
Core Material
1.
11.5
SL/HL
Explain why methanol has a much higher boiling point than ethane (Mr = 30).
2. (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 and draw its structure.
(ii)
3
State and explain the role of sulfuric acid in this reaction.
[2]
[4]
[2]
Ethanol may be converted to ethanoic acid.
(i)
Identify the reagent needed and state the type of reaction.
[2]
(ii)
State the colour change observed during the reaction.
[1]
4. (i) Explain the term condensation and state the structural features of the monomers
required to form condensation polymers. How does addition polymerisation differ
from condensation polymerisation?
(ii) Terylene is a polymer produced from the polymerisation of the two monomers
ethane- 1,2-diol and benzene-1,4-dicarboxylic acid. State what type of polymer
Terylene is and draw the structural formula of its repeating unit.
5. For each of the following conversions:
(i)
ethene → poly(ethene)
(ii)
ethanol → ethyl ethanoate
(iii)
any 2-aminoacid → a tripeptide
identify the type of reaction, the reagent(s) needed, the condition(s) needed and the structural
formula of the product.
[12]
[3]
[3]
Topic 11
Chemistry
Organic
11.6
HLONLY
Determination of structure
1. The low resolution 1H-NMR spectrum shown above could be given by
A.
CH3OH.
B.
CH3CH2OH.
C.
HCHO.
D.
HCOOH.
2. Which of the compounds below will show a single peak in its 1H-NMR spectrum?
A.
I only
B.
III only
C.
I and II only
D.
I,II and III
3.
A compound shows the following spectroscopic results:
mass spectrum;
Peaks at 15 and 46 (no peak at 29)
ir spectrum;
No peak attributable to -OH
From this information the structure of the compound is most likely
A. CH3OCH3
B.
HCOOC 2 H 5
C.
C2H5OH
D.
HCOOH
4. The mass spectrum of CH3COOC2H5 is not expected to show a major ion peak at which m/e ratio?
A.
88
B.
32
C.
29
D.
15
5. The infrared spectrum of a compound shows a broad absorption band at 3325 cm-1 and another band at
1060 cm-1, but no absorption around 1700 cm-1. Which type of compound is it most likely to be?
A Amine
B.
Alkanol
C.
Alkanone
D.
Alkanoic acid
6. How many different hydrogen signals would be present in the 1H-NMR spectrum of
2-chloropropane, CH 3 CHClCH 3 ?
A.
One
B.
Two
C.
Three
D.
Seven
7. How many lines would be expected in the proton NMR spectrum of benzene, C6H6 ?
A.
1
B.
2
C.
6
D.
42
8.How many different environments for hydrogen atoms are present in the 1H-NMR spectrum of the
following compound?
(CH3)2CHCH2CH3
A.
3
B.
4
C.
5
D.
9
9. How many lines are present in the 1H-NMR spectrum of C(CH3)4 ?
A.
1
B.
3
C.
4
D.
12
I
10.
X is an organic compound composed of carbon, hydrogen and oxygen, containing 48.63 % carbon
and 8.18% hydrogen by mass.
(a)
Calculate the empirical formula of X.
(b)
The mass spectrum for X is shown below.
(c)
[4]
(i)
Deduce, giving a reason, the molecular formula of X.
[2]
(ii)
Identify the formulas of the fragment ions with m/z values of 45 and 29.
[2]
The infrared spectrum of X is shown below.
Using the above spectrum,
(i)
(ii)
(d)
(e)
(f)
explain why X is not a carboxylic acid.
identify, giving reasons, three bonds that are present in X
[I]
[3]
Deduce the most likely structural formula of X based on your answers to (b) and (c). State
the name of X and give one use of compounds belonging to this homologous series.
[3]
State and explain the number of peaks compound X will show in its low resolution 1H-NMR
spectrum,
[2]
State me names of two compounds which could react together to produce X. Identify the type
of reaction and give an equation for the reaction.
[4]
Topic 11
Organic Chemistry
11.7
Higher Level Reactions of Alkanes, Alkenes and Alcohols HL ONLY
1. Which is a correct description of a free radical?
A.
It is a negatively charged species formed by the homolytic fission of a covalent bond
B.
It is a neutral species formed by the heterolytic fission of a covalent bond
C.
It has an unpaired electron and is formed by the heterolytic fission of a covalent bond
D.
It has an unpaired electron and is formed by the homolytic fission of a covalent bond
2. Which compound reacts by electrophilic substitution?
A. 1-Bromobutane
B. Cyclohexane
C. Methylbenzene
D. Propanone
3
Which of the compounds below is/are more likely to undergo substitution, rather than addition,
reactions? I.
II.
(CH3)3CC1
III.
C6H6
A. I only
B. II only
C. I and III only
D. II and III only
CH3CHCH2
4. In which of the following ways does benzene, C6H6, react?
I.
Combustion
II.
Hydrogenation
III.
Substitution
A.
I only
B.
I and II only
C.
I and III only
D.
I,II and III
5. Which alkene can be formed by the dehydration of pentan-2-ol?
A. CH2CHCH(CH3)2
B. CH2C(CH3)CH2CH3
C. CH3CHCHCH3
D. CH2CH(CH2)2CH3
6. An organic liquid L has a relative molecular mass of 46. On heating with concentrated H2SO4 at
170 °C, a colourless gas is evolved which decolourises Br2 (aq). What is the organic liquid L?
A.
CH3CH2OH
B.
CH3OCH3
C.
CH3CH=CH2
D.
CH3OH
7. Which will be the main product when ethanol reacts with excess concentrated
phosphoric acid?
A.
Ethene
B.
Methoxymethane
C.
Ethanoic acid
D.
Ethanal
8.
Alkanes are often described as having low reactivity, although they do react with halogens.
(i)
Explain why alkanes are unreactive.
[2]
(ii) The first step in the reaction of propane with bromine can be represented by the equation.
Br2→ 2Br∙
State the type of species formed in this step and name the type of bond fission.
[2]
9. This question is concerned with compounds having the molecular formula C3H8O. (Refer to the
Chemistry Data Booklet to help answer this question.)
(a)
Draw the full structural formulas of the three possible isomers and give the name of each.
[6]
(b)
Predict how each of these isomers would behave when reacted with limited (i.e. not in
excess) acidified potassium dichromate(VI) solution and describe any observation that
could be made. Write the structures of any organic products formed and give their names.
[8]
The infra-red spectrum of one of the three possible isomers shows an absorption band at
1000-1300 cm-1, but no absorption bands above 3000 cm-1. State to which of these three isomers
this spectrum can be assigned and give your reasoning.
[3]
(c)
(d)
Two of these isomers give the following NMR spectra:
Spectrum A with peak areas in the ratio 3:2:2:1
Spectrum B with peak areas in the ratio 6:1:1
Assign each of these spectra to one of the isomers you have drawn and outline your
reasoning.
(e)
[4]
Two of these isomers can be dehydrated to give the same product. Identify the two isomers
and give the structure of the product. Give an equation for a characteristic reaction of the
product.
[4]
Topic 11
Organic Chemistry
11.8
Nucleophillic Substitution Reactions of Halogenoalkanes HLONLY
1.
The alkaline hydrolysis of primary halogenoalkanes usually follows an SN 2 mechanism. For which
compound would the rate of hydrolysis be fastest?
A. CH3CH2CH2F
2.
B.
CH3CH2CH2C1
C.
CH3CH2CH2Br
D.
CH3CH2CH2I
Which one of the chloroalkanes below will hydrolyse most
rapidly? A.
CH3CH2CH2CH2C1
3. Which molecule does not act as a nucleophile in a reaction with a halogenoalkane?
A. Ethane
B. Ethanol
C. Ethylamine
D. Water
4. What is the correct order of reaction types in the following sequence?
I
II
III
A.
substitution
oxidation
esterification
B.
addition
substitution
substitution
C.
oxidation
substitution
addition
D.
substitution
oxidation
substitution
5.
What is the major product when an halogenoalkane (alkyl halide) is reacted with a large
excess of ammonia?
A.
An amine
B.
An amide
C.
A tetraalkyl ammonium halide
D.
An alkene
6. The reaction between 1-bromopropane and warm dilute sodium hydroxide solution is described as an
SN 2 nucleophilic substitution reaction.
(i)
Explain each of the terms in SN 2.
[3]
(ii)
Write an equation and a mechanism for the reaction.
[5]
7.(i) 1-bromopropane is described as a primary halogenoalkane and 2-bromopropane is
described as a secondary halogenoalkane. Explain these terms with reference to the
two examples given.
[2]
(ii)
Give the structural formula of a tertiary halogenoalkane.
[1]
(iii)
State the type of substitution reaction undergone by tertiary halogenoalkanes.
[1]
Draw the structures of 2-chloropropanoic acid and 2-hydroxypropanoic acid.
[2]
8.(i)
(ii)
2-chloropropanoic acid can be converted to 2-hydroxypropanoic acid by nucleophilic
substitution. Define the term nucleophile and state the nucleophile required for this
reaction.
(iii) 2-chloropropanoic acid and 2-hydroxypropanoic acid can both show optical activity.
Identify the feature which both molecules possess that accounts for this property.
When 2-hydroxypropanoic acid is formed from 2-chloropropanoic acid, the product
shows no optical activity. Deduce the type of nucleophilic substitution that takes place
and explain your answer.
[2]
[4]
Topic 11
Organic Chemistry
Higher Level Material
11.9
HL ONLY
This question is about four compounds A, B, C and D. B, C and D can be made from A by the
following reactions. A, B and C are liquid at room temperature, and each compound's molecular
formula is shown.
Sodium was added to each liquid compound. Gas bubbles formed slowly in A but rapidly in C. The
infrared spectra of the compounds showed characteristic absorptions at the following
wavenumbers (cm-1):
A:
B:
C:
D:
3400
1720
1720 and 3100
1650
(a)
Explain, by referring to the Data Booklet, how the infrared absorptions listed above can be
used to identify the functional groups present in each of the compounds A, B, C and D.
[4]
Use the information above to identify each of the compounds A, B, C and D, giving the
name and structural formula of each one.
[4]
(b)
(c)
(i)
(ii)
(d)
(e)
State the type of reaction occurring when A is converted to B and C, and state a
suitable reagent and conditions for the reaction.
[3]
Explain why B is much harder to obtain than C in this reaction.
[1]
State the type of reaction occurring when A is converted to D, and name a catalyst that is
used. What other product is formed as well as D?
[3]
Identify the gas formed when A and C react with sodium and write an equation for each of
the reactions occurring. Name the other product of the reaction between sodium and C.
[4]
(f)
Arrange the compounds A, B and C in increasing order of boiling point (lowest boiling point
first). Explain your choice.
[4]
(g)
None of the compounds A, B, C and D exist as optical isomers. State the structural feature
which is present in a compound that exists as optical isomers. Draw the structural formula of
the isomer of A that exists as optical isomers,
[2]
Topic 11
Organic Chemistry
Extension
11.10
HL ONLY
(a) Compound A is a bromoalkane. When compound A reacts with warm
dilute sodium hydroxide solution an organic compound B is formed
which has a relative molar mass of 74.12 and contains 64.81 % carbon,
13.60 % hydrogen and 21.59 % oxygen by mass. Compound B can be
oxidised by an acidified solution of potassium dichromate(VI) to give
compound C which contains the same number of carbon atoms as
compound B and which shows an absorption peak at 1720 cm-1 in the
infra-red spectrum.
(i)
Calculate the empirical and molecular formula of compound B.
(ii)
Give four different possible structural formulas for isomers of
compound B which are consistent with the information that it has
been formed from the reaction of a bromoalkane with NaOH (aq).
[4 marks]
Which of the four isomers given in (ii) above is not consistent
with the fact that compound B can be oxidised by an acidified
solution of K2Cr2O7 to give compound C? Explain your answer.
[2 marks]
Give the structures of the organic products which would be
formed when the remaining three structural isomers of compound
B are fully oxidised by acidified K2Cr2O7.
[3 marks]
What is responsible for the sharp absorption peak at 1720 cm-1 ?
[1 mark]
(iii)
(iv)
(v)
(b)
1
[3 mark]
It is shown that compound B exhibits optical activity.
(i)
(ii)
(iii)
Explain what is meant by optical activity and show clearly the two
optical isomers of compound B.
[4 marks]
Give the structural formulas and names of compound A and
compound C.
[4 marks]
Name the mechanism which describes the reaction between
compound A and dilute sodium hydroxide solution.
[1 mark]
(iv) Give the balanced equation for the reaction of compound B with
ethanoic acid in the presence of sulfuric acid and name the
functional group present in the organic product
[3 marks]