What are possible names of a molecule with molecular formula C₄H₁₀O?

        I.     1-Methoxypropane

        II.     2-Methylpropan-2-ol

        III.     Butanal

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

A

What is the order of increasing boiling point?

A.     C₄H₁₀ < CH₃COOH < CH₃CH₂CHO < CH₃CH₂CH₂OH

B.     C₄H₁₀ < CH₃CH₂CHO < CH₃CH₂CH₂OH < CH₃COOH

C.     CH₃COOH < CH₃CH₂CH₂OH< CH₃CH₂CHO < C₄H₁₀

D.     C₄H₁₀ < CH₃CH₂CH₂OH < CH₃CH₂CHO < CH₃COOH

B

Which alcohols are oxidized by acidified potassium dichromate(VI) solution when heated?

A. I and II only 

B. I and III only 

C. II and III only 

D. I, II and III

A

Which monomer is used to form the polymer with the following repeating unit?

A. CH₃CH=CHCH₃ 

B. CH₃CH₂CH=CH₂ 

C. CH₃CH₂CH₂CH₃ 

D. (CH₃)₂C=CH₂

A

Which of these reactions proceeds by a free radical mechanism in the presence of UV light?

A.     C₆H₆ + Cl₂ → C₆H₅Cl + HCl

B.     C₆H₆ + 3H₂ → C₆H₁₂

C.     CH₂CH₂ + HBr → CH₃CH₂Br

D.     CH₃CH₃ + Cl₂ → CH₃CH₂Cl + HCl

D

What is the mechanism for the reaction of propene with iodine in the dark?

A.     electrophilic addition

B.     electrophilic substitution

C.     free radical substitution

D.     nucleophilic substitution

A

Which reagents and conditions are best for converting propan-1-ol into propanoic acid?

A.  Reflux with acidified potassium dichromate (VI)

B.  Reflux with aqueous sodium hydroxide

C.  Distil with acidified potassium dichromate (VI)

D.  Distil with aqueous sodium hydroxide

A

Which compounds belong to the same homologous series?

A.     CHCCH₂CH₃, CHCCH₂CH₂CH₃

B.     CH₃CH₂CH₂CH₂OH, CH₃CH₂OCH₂CH₃

C.     CH₂CHCH₃, CH₃CH₂CH₂CH₃

D.     CH₃COCH₃, CH₃CH₂OCH₃

A

Which functional groups are present in serine?

A.  nitro, carbonyl and carboxyl

B.  amino, hydroxyl and carbonyl

C.  nitro, carboxyl and hydroxyl

D.  amino, carboxyl and hydroxyl

D

What is produced when chlorobutane is treated with aqueous sodium hydroxide solution?

A.  butane

B.  butanoic acid

C.  butanal

D.  butan-1-ol

D

Which reaction mechanisms are typical for alcohols and halogenoalkanes?

D

Only 25% of the candidates deduced the reaction mechanisms that are typical for alcohols and halogenoalkanes. Candidates were expected to deduce that the reactions would be substitutions since both compounds are saturated.

How many dichlorinated butane isomers can be formed by the halogenation of CH₃CH₂CH₂CH₃ with excess Cl₂ in the presence of UV light?

A.  4

B.  6

C.  8

D.  10

B

Candidates had to work out the possible number of isomers of dichlorobutane and the majority only thought of 4 of the 6 possible isomers. 32% of the candidates obtained the correct answer.

Which describes the reaction between a halogen and ethane?

A

What type of reaction occurs when C₆H₁₃Br becomes C₆H₁₃OH?

A.  Nucleophilic substitution

B.  Electrophilic substitution

C.  Radical substitution

D.  Addition

A

What is the name of this compound, using IUPAC rules?

A.     1,1-dimethylpropanoic acid

B.     3,3-dimethylpropanoic acid

C.     2-methylbutanoic acid

D.     3-methylbutanoic acid

D

What is the name of the compound with this molecular structure applying IUPAC rules?

A.     1-methylpropanoic acid

B.     2-methylpropanoic acid

C.     2-methylbutanoic acid

D.     3-methylbutanoic acid

C

What is the IUPAC name of the following molecule?

A. 2-bromo-3-ethylbutane

B. 3-methyl-4-bromopentane

C. 2-ethyl-3-bromobutane

D. 2-bromo-3-methylpentane

D

57 % of candidates could correctly apply IUPAC nomenclature.

Which functional group is surrounded in the molecule?

A. hydroxyl

B. carboxyl

C. carbonyl

D. ether

C

One G2 comment stated “the functional group by definition is an aldehyde, however, students must assume that the H should be considered as an 'R group in order to call it a carbonyl”. However, aldehyde was not an alternative answer, with the main misconception considering the C=O as a carboxyl rather than carbonyl.

Which structure represents a repeating unit of a polymer formed from propene?

A.  –CH₂–CH(CH₃)–

B.  –CH₂–CH₂–CH₂–

C.  –CH(CH₃)–CH(CH₃)–

D.  –CH₂–CH₂–

A

44% of the candidates identified the repeating unit of the polymer formed from propene. The most commonly chosen distractor was a straight chain.

Which compound has the lowest boiling point?

A. CH₃CH₂CH₂CH₂CH₂CH₃

B. CH₃CH₂CH₂CH₂CH₃

C. CH₃CH(CH₃)CH₂CH₃

D. CH₃C(CH₃)₂CH₃

D

Surprisingly, this was one of the challenging questions on the paper. Only 57 % of the candidates chose dimethylpropane as the compound having the lowest boiling point. The most commonly chosen distractor was pentane (B) which did not take into account the effect of branching on the strength of London dispersion forces.

What is the mechanism of the reaction between alkenes and halogens in the absence of light?

A. radical substitution

B. electrophilic substitution

C. electrophilic addition

D. nucleophilic substitution

C

Only 33 % of candidates could identify the mechanism type with a large confusion between electrophilic addition and substitution.

Which type of reaction occurs when methanol and propanoic acid react together in the presence of a catalyst?

A. Addition

B. Condensation

C. Redox

D. Neutralization 

B

Which type of reaction occurs between an alcohol and a carboxylic acid?

A. Addition

B. Oxidation

C. Esterification

D. Polymerization

C

Which molecule has a tertiary nitrogen?

A.     (CH₃)₂NH

B.     (C₂H₅)₄N⁺I⁻

C.     C₃H₇N(CH₃)₂

D.     C₆H₅NH₂

C

Which compound could be formed when CH₃CH₂CH₂OH is heated with acidified potassium dichromate(VI)?

        I.     CH₃CH₂CHO

        II.     CH₃CH₂COOH

        III.     CH₃COCH₃

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

A

What is the major product of the reaction between HCl and but-2-ene?

A. 1,2-dichlorobutane

B. 2,3-dichlorobutane

C. 1-chlorobutane

D. 2-chlorobutane

D

How many structural isomers of C₆H₁₄ exist?

A. 4

B. 5

C. 6

D. 7

B

What is the general formula of alkynes?

A.  C_nH_2n+2

B.  C_nH_2n

C.  C_nH2_n−2

D.  C_nH_n

C

Which series is in order of increasing boiling point?

A.  CH₂CH₂CH₃OH    CH₃COCH₃         CH₃CH₂CH₃

B.  CH₃CH₂CH₃         CH₃COCH₃          CH₂CH₂CH₃OH

C.  CH₃COCH₃          CH₂CH₂CH₃OH    CH₃CH₂CH₃

D.  CH₃CH₂CH₃         CH₂CH₂CH₃OH    CH₃COCH₃

B

Which conditions are used to convert ethanol to ethanal?

A.     Excess oxidizing agent and reflux

B.     Excess oxidizing agent and distillation

C.     Excess ethanol and reflux

D.     Excess ethanol and distillation

D

The structure of a drug used to treat symptoms of Alzheimer’s disease is shown below. Which functional groups are present in this molecule?

A. Hydroxyl and ester 

B. Hydroxide and ether 

C. Hydroxyl and ether 

D. Hydroxide and ester

C

Which compound cannot undergo addition polymerization?

C

Which alcohol would produce a carboxylic acid when heated with acidified potassium dichromate(VI)?

A. propan-2-ol

B. butan-1-ol

C. 2-methylpropan-2-ol

D. pentan-3-ol

B

The largest gap between high scoring and low scoring candidates was on this question about oxidation of alcohols.

Which compounds react to form CH₃CH₂CH₂COOCH(CH₃)₂?

A.   propanoic acid and propan-2-ol

B.   propanoic acid and butan-2-ol

C.   butanoic acid and propan-1-ol

D.   butanoic acid and propan-2-ol

D

Which is correct for benzene?

A.   It readily undergoes addition reactions and decolourises bromine water.

B.   It contains alternate single and double carbon–carbon bonds and is planar.

C.   Its ¹H NMR spectrum shows six signals and it readily undergoes substitution reactions.

D.   Its ¹H NMR spectrum shows one signal and it forms a single C₆H₅Br isomer.

D

Which compounds cause the colour of acidified potassium manganate(VII) solution to change from purple to colourless?

I.    CH₃CH₂CH₂CH₂OH

II.   (CH₃)₃CCH₂OH

III.  CH₃CH₂CH(OH)CH₃

A.   I and II only

B.   I and III only

C.   II and III only

D.   I, II and III

D

Which of the following can be both formed from bromoethane and converted directly into ethanal?

CH₃CH₂Br → X
X → CH₃CHO

A. CH₃CH₂OH

B. CH₃OCH₃

C. CH₃COOH

D. H₂C=CHBr

A

The question involving a sequence of organic reactions discriminated well between high scoring and low scoring candidates. 68 % chose the correct compound.

Methane reacts with chlorine in sunlight.

CH₄ (g) + Cl₂ (g) → CH₃Cl (g) + HCl (g)

Which type of reaction occurs?

A. free-radical substitution

B. electrophilic substitution

C. nucleophilic substitution

D. electrophilic addition

A

74 % of the candidates chose free-radical substitution as the type of reaction occurring between methane and chlorine in sunlight.

Which functional group is present in paracetamol?

A.     Carboxyl

B.     Amino

C.     Nitrile

D.     Hydroxyl

D

What is the name of this compound, applying IUPAC rules?

A.  4-methylhex-2-ene

B.  4-ethylpent-2-ene

C.  2-ethylpent-3-ene

D.  3-methylhex-4-ene

A

Which compound can be oxidized when heated with an acidified solution of potassium dichromate(VI)?

A. CH₃C(O)CH₂CH₃

B. CH₃CH₂CH(OH)CH₃

C. (CH₃)₃COH

D. CH₃(CH₂)₂COOH

B

Which compound contains a secondary carbon atom?

A.     CH₃CH(Cl)CH(CH₃)₂

B.     (CH₃)₂CHCH₂Cl

C.     (CH₃)₃CCl

D.     CH₃CH₂Cl

A

What is the IUPAC name of the molecule shown?

A.  2,4-dimethylhexane

B.  3,5-dimethylhexane

C.  2-methyl-4-ethylpentane

D.  2-ethyl-4-methylpentane

A

What is the product of the reaction between hex-3-ene and steam?

A.     Hexan-1-ol

B.     Hexan-2-ol

C.     Hexan-3-ol

D.     Hexan-4-ol

C

Which compound is not in the same homologous series as the others?

A.  C₅H₁₂

B.  C₆H₁₂

C.  C₇H₁₆

D.  C₈H₁₈

B

Which is a homologous series?

A.  C₂H₄, C₃H₅, C₄H₆

B.  C₂H₂, C₃H₄, C₄H₆

C.  C₂H₂, C₂H₄, C₂H₆

D.  C₂H₂, C₄H₄, C₆H₆

B

45% of the candidates identified the members of the same homologous series (ethyne, propyne and butyne). The most commonly chosen distractor included the compounds C₂H₂, C₄H₄ and C₆H₆. The question had good discrimination between high-scoring and low-scoring candidates.

Which is a propagation step in the free-radical substitution mechanism of ethane with chlorine?

A.  C$\text{l}$₂ → 2 •C$\text{l}$

B.  •C₂H₅ + C$\text{l}$₂ → C₂H₅C$\text{l}$ + •C$\text{l}$

C.  •C₂H₅ + •C$\text{l}$ → C₂H₅C$\text{l}$

D.  C₂H₆ + •C$\text{l}$ → C₂H₅C$\text{l}$ + •H

B

Which are structural isomers?

       I.     CH₃CH₂OH and CH₃OCH₃

       II.     HOCH₂CH₃ and CH₃CH₂OH

       III.     CH₃COOH and HCOOCH₃

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

B

What is the name of this substance using IUPAC rules?

A.  2-ethyl-1-methylbutan-1-ol

B.  1-methyl-2-ethylbutan-1-ol

C.  3-ethylpentan-2-ol

D.  3-ethylpentan-4-ol

C

Which monomer would produce the polymer shown?

A.  ${\text{CF}}_{\text{3}}{\text{CCl}}_{\text{2}}\text{F}$

B.  ${\text{CF}}_{\text{3}}\text{CClHF}$

C.  ${\text{CF}}_{\text{2}}\text{CClF}$

D.  ${\text{CF}}_{\text{2}}{\text{CF}}_{\text{2}}$

C

What is the IUPAC name of this molecule?

A.  1,1,2,4-tetramethylpent-1-ene

B.  2,4,5-trimethylhex-4-ene

C.  2,4,5,5-tetramethylpent-4-ene

D.  2,3,5-trimethylhex-2-ene

D

It was good to see that 2/3 of candidates could pick a preferred IUPAC name from a skeletal structure.

Which is in the same homologous series as CH₃OCH₃?

A.  CH₃COCH₃

B.  CH₃COOCH₃

C.  CH₃CH₂CH₂OH

D.  CH₃CH₂CH₂OCH₃

D

Which monomer forms the polymer shown?

A.  ${\text{CH(Cl)=CH(CH}}_{\text{3}}\text{)}$

B.  ${\text{CH}}_{\text{2}}{\text{=C(Cl)CH}}_{\text{3}}$

C.  ${\text{(CH}}_{\text{3}}{\text{)}}_{\text{2}}\text{CHCl}$

D.  ${\text{CH}}_{\text{2}}\text{=CHCl}$

A

Which spectra would show the difference between propan-2-ol, CH₃CH(OH)CH₃, and propanal, CH₃CH₂CHO?

I.   mass
II.  infrared
III. ¹H NMR

A.  I and II only

B.  I and III only

C.  II and III only

D.  I, II and III

D

What are the functional groups in the aspirin molecule?

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

C

What is the order of increasing boiling point for the isomers of C₅H₁₂?

A.   CH₃CH₂CH₂CH₂CH₃ < CH₃CH(CH₃)CH₂CH₃ < CH₃C(CH₃)₃

B.   CH₃C(CH₃)₃ < CH₃CH(CH₃)CH₂CH₃ < CH₃CH₂CH₂CH₂CH₃

C.   CH₃C(CH₃)₃ < CH₃CH₂CH₂CH₂CH₃ < CH₃CH(CH₃)CH₂CH₃

D.   CH₃CH(CH₃)CH₂CH₃ < CH₃C(CH₃)₃ < CH₃CH₂CH₂CH₂CH₃

B

What is the name of this compound, using IUPAC rules?

A. 3-methylbutan-3-ol

B. 2-ethylpropan-2-ol

C. 2-methylbutan-2-ol

D. 3-methylbutan-2-ol

C

Which will react with a halogen by an electrophilic substitution mechanism?

A

Which pair of compounds are structural isomers?

A.  Propane and propene

B.  Propanal and propanone

C.  Propan-1-ol and propanal

D.  Propyl propanoate and propanoic acid

B

Which combination best describes what is happening to chloromethane, CH₃Cl, in the equation below?

CH₃Cl (g) + H₂(g) $\rightleftharpoons$ CH₄(g) + HCl (g)

A.  Oxidation and addition

B.  Oxidation and substitution

C.  Reduction and addition

D.  Reduction and substitution

D

57% of the candidates were able to identify the type of reaction (oxidation or reduction & addition or substitution) correctly.

Which compounds are members of the same homologous series?

A.  propanal, propanone, propanoic acid

B.  propane, propene, propyne

C.  hexan-1-ol, hexan-2-ol, hexan-3-ol

D.  ethanol, propan-1-ol, butan-1-ol

D

What is formed in a propagation step of the substitution reaction between bromine and ethane?

A.  CH₃CH₂•

B.  CH₃CH₂CH₂CH₃

C.  H•

D.  Br⁻

A

Which mechanism does benzene most readily undergo?

A.  Nucleophilic substitution

B.  Electrophilic substitution

C.  Electrophilic addition

D.  Free radical substitution

B

Vast majority of candidates understood benzene undergoes substitution rather than addition, with some thinking of it as nucleophilic rather than electrophilic substitution.

Which functional groups are present in this molecule?

A.  carbonyl, ether, nitrile

B.  carbonyl, ester, nitrile

C.  carboxyl, ether, amine

D.  carboxyl, ester, amine

A

This question on identifying functional groups was the most discriminating question on the paper. 58% correctly identified all three groups but it was answered much better by higher scoring candidates.

Which molecule will decolorize bromine water in the dark?

A.  cyclohexane

B.  hexane

C.  hex-1-ene

D.  hexan-1-ol

C

Two-thirds of candidates knew that hex-1-ene would decolourize bromine water in the dark.