Syllabus Edition

First teaching 2023

First exams 2025

|

Functional Groups: Classification of Organic Compounds (HL IB Chemistry)

Exam Questions

7 hours115 questions
11 mark

Which of the following shows the correct order of boiling points for pentane, butane and propane?

  • CH3CH2CH3 > CH3CH2CH2CH3 > CH3CH2CH2CH2CH3

  • CH3CH2CH2CH2CH3 > CH3CH2CH2CH3 > CH3CH2CH3

  • CH3CH2CH2CH3 > CH3CH2CH2CH2CH3 > CH3CH2CH3 

  • CH3CH2CH3 > CH3CH2CH2CH2CH3 > CH3CH2CH2CH3  

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21 mark

Which of the following statements about propanal, CH3CH2CHO, and propanone, CH3COCH3 is not correct? 

The compounds have:

  • molecular ion peaks at different mass to charge ratios

  • different fragmentation patterns in the mass spectrum

  • absorption in the infrared spectrum due to the carbonyl group

  • a different fingerprint region in the infrared spectrum

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31 mark

Nitrogen trichloride has the formula NCl3. A sample was found to contain only 14N, and chlorine atoms with mass numbers 35 and 37. 

Which of the following is an incorrect ion and mass/charge ratio responsible for the molecular ion peaks found in the mass spectrum of nitrogen trichloride? 

 

ion

m/e

A

N(35Cl)3+

119

B

N(35Cl)237Cl+

121

C

N35Cl(37Cl)2+

123

D

N(37Cl)2+

125

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    41 mark

    Which of the following cannot be obtained from an infrared spectrum?

    • the molecular mass

    • the presence of C=O bonds

    • the presence of O-H bonds

    • the identity of a compound through comparison with other spectra

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    51 mark

    What information can be determined from the infrared spectrum of a molecule?

    • The number of hydrogens

    • The number of hydrogen environments

    • The type of bonds present

    • The relative molecular mass

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    61 mark

    Which of the following bonds will produce strong absorptions in the infrared part of the electromagnetic spectrum? 

      1.    C-N
      2.    O=O
      3.    C=O
    • I and II only  

    • I and III only  

    • II and III only 

    • I, II and III

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    71 mark

    Which of the following is true about the fingerprint region in the IR spectrum of alcohols?

    • The fingerprint region is where single bonds can be identified in the IR spectrum  

    • The fingerprint region is unique to every molecule  

    • The fingerprint region does not provide useful information about molecules 

    • A functional group can be identified from the fingerprint region

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    81 mark

    Which of the following statements is correct about spectroscopic techniques for organic molecules?

    • Information about bond vibrations can be deduced from mass spectroscopy 

    • The values of carbon–hydrogen bond lengths can be found from 1H NMR spectroscopy 

    • The number of hydrogen atoms can be determined from infrared spectroscopy

    • Information about molecular structure can be found from mass spectroscopy

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    91 mark

    In the 1H NMR spectrum of 3-methylbutan-1-ol what is the ratio of the peak areas under each signal?

    • 6 : 1 : 2 : 2 : 1

    • 3 : 3 : 1 : 5 : 1

    • 6 : 1 : 5 : 1

    • 3 : 3 : 1 : 2 : 3

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    101 mark

    Which of the following types of spectroscopic identification will involve bond fission in organic molecules?

    • Nuclear magnetic spectroscopy  

    • Infrared spectroscopy 

    • Mass spectrometry 

    • X-ray crystallography

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    111 mark

    Which pairs of homologous series do not have the same C:H ratio in their general formulae?

    • aldehydes and ketones

    • alkanes and alkenes

    • carboxylic acids and esters

    • alkenes and aldehydes

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    121 mark

    Which of the following molecules are hydrocarbons?

    10-1-q2-ib-chemisrey-mcq

    • All

    • 1 and 2

    • 1, 2 and 3

    • 2, 3 and 4

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    131 mark

    What is the correct formula for 1-fluoro-3-methylbut-2-ene?

              A           

                         Molecular                          

             CH2FCH2C(CH3)CH3

    B

    Empirical

    C5H9F

    C

    Displayed

    10-1-q3-ib-chemisrey-mcq

    D

    Skeletal

     

    10-1-e-q3-ib-chemistry-mcq    

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      141 mark

      Considering only structural isomers, what is the number of alcohols of each type with the formula C5H12O?

                   

               primary        

             secondary      

            tertiary    

      A

      B

      C

      D

      3

      4

      4

      5

      3

      2

      3

      2

      2

      2

      1

      1

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        151 mark

        Which of the following is the displayed formula for ethylamine?

        10-1-q5-ib-chemisrey-mcq

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          161 mark

          Identify which of the hydrocarbons shown below does not belong in the same homologous series as the other compounds

          • C5H12

          • C6H12

          • C7H16

          • C8H18

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          171 mark

          Identify the functional group that is ringed in the molecule shown below:

          10-1-q7-ib-chemisrey-mcq

          • hydroxyl

          • carboxyl

          • ether

          • carbonyl

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          181 mark

          What is the IUPAC name of the following molecule?10-1-q8-ib-chemisrey-mcq

          •  2-chloro-3-ethylbutane

          • 3-methyl-4-chloropentane

          • 2-ethyl-3-chlorobutane

          • 2-chloro-3-methylpentane

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          191 mark

          What is the IUPAC name of the following molecule?10-1-q9-ib-chemisrey-mcq

          • 3,3-dimethylpropanoic acid

          • 1,1-dimethylpropanoic acid

          • 3-methylbutanoic acid

          • 2-methylbutanoic acid

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          201 mark

          Which of the halogenoalkanes shown contains a secondary carbon atom?

          • (CH3)2CHCH2Cl

          • CH3(CH2)3CH2Cl

          • (CH3)3CCl

          • CH3CHClCH2CH3

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          21
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          1 mark

          Which molecule contains a chiral carbon?

          • 1-chloro-2-methylbutane

          • 2-methylpropane

          • Butane

          • 2-chloropropane

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          22
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          1 mark

          What is name of this compound applying IUPAC rules?

          1f99b13b-fc61-4666-855a-a545bf627b9a

          • Trans-pent-2-ene

          • Trans-but-2-ene

          • But-1-ene

          • Cis-but-2-ene

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          23
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          1 mark

          Which statement about isomerism is correct?

          • A racemic mixture is optically active 

          • Pent-1-ene exhibits stereoisomerism 

          • 1-bromopropane has two optical isomers 

          • 2-amino-3-methylpentane is a diastereomer

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          24
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          1 mark

          Which pair are cis and trans isomers?

          • aIKHR5cw_20-3-a-ib-mcq

          • 20-3-b---ib-mcq

          • 20-3-c---ib-mcq

          • 20-3-d---ib-mcq

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          11 mark

          Xylitol is an artificial sweetener used in toothpastes and chewing gum to improve their taste without impairing dental hygiene.10-2-m-q1-ib-chemistry-mcqs

          Which functional groups could be produced if Xylitol is oxidised under suitable conditions?

           

          1

                        alkene

          2

                        aldehyde

          3

                        carboxylic acid

          4

                        ketone

          • 1 only

          • 2 only

          • 2, 3 and 4

          • 2 and 4

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          21 mark

          Which alcohol is not likely to have a fragment at m/e at 43 in its mass spectrum?

          • (CH3)2CHCH2OH

          • CH3CH(OH)CH2CH2CH3

          • CH3CH2CH2CH2OH

          • CH3CH2CH(OH)CH3

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          31 mark

          Which of the compounds shown below is likely to have a fragment at m/e = 45 in its mass spectrum?

          11-1-mcq-q2-medium-ib-chemistry

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            41 mark

            Chlorine has two isotopes 35Cl and 37Cl.  Assuming in the molecule C4H6Cl4 there is only one hydrogen and one carbon isotope, how many molecular ion peaks will be seen in its mass spectrum?

            • 5

            • 4

            • 3

            • 2

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            51 mark

            Bromine exists as two isotopes 79Br and 81Br, which are found in almost equal abundance. 

            Which of the following statements is correct?

            • 79Br is more reactive than 81Br

            • The mass spectrum of C3H7Br has two molecular ion peaks at 122 and 124

            • The atomic radius of 79Br is less than the atomic radius of 81Br

            • The first ionisation energy of 79Br is less than the first ionisation energy of 81Br

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            61 mark

            Which alcohol is likely to have a fragment ion at m/e = 31 in its mass spectrum?

            • CH3)2CHCH2OH

            • CH3CH(OH)CH2CH2CH3

            • CH3CH2CH2C(OH)(CH3)2

            • CH3CH2CH(OH)CH3

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            71 mark

            Which pair of compounds would you expect to both have a singly charged peak at m/e = 29 in the mass spectrum? 

            • propan-1-ol and propanal

            • propanal and propanone

            • propan-2-ol and propanal

            • propan-1-ol and propan-2-ol

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            81 mark

            The infrared spectrum of a compound is shown below.

            d6mgC1_0_11-1-mcq-q7-medium-ib-chemistry

            Use the infrared absorptions, in wavenumbers, to identify the compound 

            bond

            wavenumber range/ cm-1

            O−H (alcohol)

            3750 – 3200

            C−H (alkane)

            2962 – 2853

            C−H (aldehyde)

            2900 – 2820 and 2775 – 2700

            C═O (aldehyde or ketone)

            1740 - 1680

             

            Which compound is shown by the infrared spectrum?

            • propan-1-ol

            • propan-2-ol

            • propanal

            • propanone

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            91 mark

            Which of the ketones listed would not be expected to have a peak in its mass spectrum at m/e = 57?

            • hexan-3-one, CH3CH2CH2COCH2CH3

            • pentan-3-one, CH3CH2COCH2CH3

            • 3-methylbutanone, (CH3)2CHCOCH3

            • butanone, CH3CH2COCH3

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            101 mark

            Which of the following statements about the mass spectrum of CH3Br is correct?

            • There is one peak for the molecular ion with an m/e value of 44.

            • There is one peak for the molecular ion with an m/e value of 95.

            • The last two peaks have abundances in the ratio 3:1 and occur at m/e values of 94 and 96.

            • The last two peaks are of equal size and occur at m/e values of 94 and 96.

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            111 mark

            Below is a 1H NMR spectrum for an unknown organic compound. The relative areas under the peaks are labelled

            11-1-mcq-q10-medium-ib-chemistry

            Which of the following compounds could give this spectrum?

            • propan-1-ol, CH3CH2CH2OH

            • propan-2-ol, CH3CH(OH)CH3

            • methyoxyethane, CH3OCH2CH3

            • pentan-2-one, CH3CH2CH2COCH3

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            121 mark

            How many structural isomers are there of tribromopropane, C3H5Br3?

            • 4

            • 5

            • 6

            • 7

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            131 mark

            How many isomeric esters have the molecular formula C5H10O2?

            • 4

            • 5

            • 9

            • 7

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            141 mark

            Which features about the members of a homologous series are correct?

            1.  all members have the same general formul
            2.  the members have similar chemical properties
            3.  the members show a gradual change in physical properties
            • I and II only

            • I and III only

            • II and III only

            • I, II and III

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            151 mark

            Octane is a component of petrol or gasoline. Which of the following molecules could be an isomer of octane?

            • CH3CH2CHCHCHCH2(CH3)2

            • (CH3)2CHCH(CH2)2(CH3)2

            • CH3(CH2)5CH3

            • CH3CHCHCH(CH2)2(CH3)2

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            161 mark

            Give the name of the following molecule10-1-m-q5-mcqs-ib-chemistry

            • 2,4,4,4-trimethylethylbutane

            • 3,3,5-trimethylhexane

            • 2,4,4-trimethylhexane

            • 1,1,3,3-tetramethylpentane

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            171 mark

            How many branched-chain isomers are there which have the molecular formula C5H12?

            • 2

            • 3

            • 4

            • 5

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            181 mark

            Study the diagram below and determine which of the three statements are correct

            10-1-m-q8-mcqs-ib-chemistry

            1.   A suitable name is hex-4-ene
            2.   The empirical formula is CH2
            3.    It is an isomer of cyclohexane
            • I and II only

            • I and III only

            • II and III only

            • I, II and III

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            191 mark

            Which of the molecules shown below contains an aldehyde functional group?

            • CH3CH2CH2OOCH3 

            • CH3CH2CH2COCH3

            • CH3CH2OCH2CH3

            • CH3CH2CH2CH2CHO

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            201 mark

            Which of the halogenoalkanes shown below contains a tertiary carbon atom?

            • CH3CH2CH2Cl

            • CH3CH2CH(CH3)Br

            • C(CH3)3Cl

            • CH3CHBrCH2CH3

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            211 mark

            What would be the name of the following compound using IUPAC rules?

            10-1-m-q10-mcqs-ib-chemistry

            • pentane

            • ethylpropane

            • 2-methylbutane

            • 3-methylbutane

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            221 mark

            Which two molecules are cis-trans isomers of each other?

            q1_16-2_ib_hl_medium_mcq

            • X and Z

            • X and Y

            • W and Y

            • W and Z

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            231 mark

            What is this molecule called?
            q2_20-3_ib_hl_medium_mcq

            • Z-2-bromo-1-chloro-2-fluoroethene

            • E-2-bromo-1-chloro-2-fluoroethene

            • Z-1-bromo-2-chloro-1-fluoroethene

            • E-1-bromo-2-chloro-1-fluoroethene

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            241 mark

            Which molecule has optical isomers?

            • 2-bromobutane

            • 1,3-dibromopropane

            • 2-chloro-2-methylpropane

            • 3-bromopentane

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            251 mark

            What is the name of this molecule?
            q4_20-3_ib_hl_medium_mcq

            • cis-3-methyl-3-hexene

            • trans-4-methyl-4-hexene

            • cis-3-methyl-2-hexene

            • trans-3-methyl-2-hexene

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            261 mark

            Which is true about stereoisomerism?

            • But-1-ene has E/Z isomers

            • Butan-2-ol has two enantiomers

            • But-1-ene and but-2-ene are cis-trans isomers

            • Butan-1-ol and butan-2-ol are optical isomers

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            11 mark

            The mass spectra of three compounds A, B and C are shown below.

            11-1-mcq-q1-fig-1-hard-ib-chemistry

            11-1-mcq-q1-fig-2-hard-ib-chemistry

            11-1-mcq-q1-fig-3-hard-ib-chemistry

            What evidence from the spectra of the three compounds A, B and C, suggests they could be isomers?

            • all show a molecular ion peak at 74

            • all show a molecular ion peak at 13

            • all show a molecular ion peak at 73

            • all show a molecular ion peak at 33

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            21 mark

            The infrared spectrum below shows an unknown compound.

            11-1-mcq-q2-hard-ib-chemistry

            bond

            wavenumber range/ cm-1

            C−O; hydroxyl, ester

            1040 – 1300

            C═C; aromatic compound, alkene

            1500 - 1680

            C═O amide

            carbonyl, carboxyl

            ester

            1640 – 1690

            1670 – 1740

            1710 - 1750

            C≡N; nitrile

            2200 – 2250

            C−H; alkane

            2850 – 2950

            N−H; amine, amide

            3300 – 3500

            O−H; carboxyl

            hydroxyl

            2500 – 3000

            3200 - 3600

            Which compound could have produced the infrared spectrum?

            11-1-mcq-q2-ma-hard-ib-chemistry

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              31 mark

              The diagram shows an infrared spectrum of a compound.

              11-1-mcq-q3-hard-ib-chemistry

              bond

              wavenumber range/ cm-1

              C−O; hydroxyl, ester

              1040 – 1300

              C═C; aromatic compound, alkene

              1500 - 1680

              C═O amide

              carbonyl, carboxyl

              ester

              1640 – 1690

              1670 – 1740

              1710 - 1750

              C≡N; nitrile

              2200 – 2250

              C−H; alkane

              2850 – 2950

              N−H; amine, amide

              3300 – 3500

              O−H; carboxyl

              hydroxyl

              2500 – 3000

              3200 - 3600

              Which compound would give this spectrum?

              • butanoic acid

              • butanal

              • butan-1-ol

              • 1-bromobutane

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              41 mark

              Which of the following infrared spectra could show a carboxylic acid?

              11-1-mcq-q4-fig-1-hard-ib-chemistry

              11-1-mcq-q4-fig-2-hard-ib-chemistry

              11-1-mcq-q4-fig-3-hard-ib-chemistry

              11-1-mcq-q4-fig-4-hard-ib-chemistry

              Bond

              Wavenumber range/ cm-1

              C−O; hydroxyl, ester

              1040 – 1300

              C═C; aromatic compound, alkene

              1500 - 1680

              C═O amide

              carbonyl, carboxyl

              ester

              1640 – 1690

              1670 – 1740

              1710 - 1750

              C≡N; nitrile

              2200 – 2250

              C−H; alkane

              2850 – 2950

              N−H; amine, amide

              3300 – 3500

              O−H; carboxyl

              hydroxyl

              2500 – 3000

              3200 - 3600

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                51 mark

                A compound XFn is a fluoride of another halogen, X, and it is known that n > 1. The highest m/e peak in the mass spectrum of XFn is assigned to the parent ion and comes as a single peak at m/e = 222. 

                Which of the following statements is incorrect?

                • n = 5

                • the compound could contain bromine

                • there are no isotopes of X or F

                • the compound is a fluoride of iodine

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                61 mark

                An organic compound is analysed by mass spectrometry and infrared spectroscopy. The following data is obtained.

                 

                mass spectrometry

                infrared spectroscopy

                molecular ion peak at m/e = 128

                sharp peak at 1720 cm-1

                fragment ion peak at m/e = 15

                no broad peak around 3200 cm-1

                 

                Bond

                Wavenumber range/ cm-1

                C−O; hydroxyl, ester

                1040 – 1300

                C═C; aromatic compound, alkene

                1500 - 1680

                C═O amide

                carbonyl, carboxyl

                ester

                1640 – 1690

                1670 – 1740

                1710 - 1750

                C≡N; nitrile

                2200 – 2250

                C−H; alkane

                2850 – 2950

                N−H; amine, amide

                3300 – 3500

                O−H; carboxyl

                hydroxyl

                2500 – 3000

                3200 - 3600

                 

                Which of the following compounds could be consistent with the data given?

                11-1-mcq-q6-hard-ib-chemistry

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                  71 mark

                  What does the 1H NMR spectrum below tell you about a molecule?

                  11-1-mcq-q7-hard-ib-chemistry

                  • There is only one isotope of hydrogen present in the molecule

                  • The molecule is a hydrocarbon

                  • There is only one hydrogen atom in the molecule

                  • There is only one hydrogen environment in the molecule

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                  81 mark

                  How many peaks would you expect to see in a 1H NMR spectrum of methylbenzene?

                  11-1-mcq-q8-hard-ib-chemistry

                  • 3

                  • 4

                  • 5

                  • 6

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                  91 mark

                  How many isomers, including structural and stereoisomers, with the formula C5H10 have structures that involve π bonding?

                  • 3

                  • 4

                  • 5

                  • 6

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                  101 mark

                  Study the formulae shown below and determine which molecules are isomers of each other

                  I.
                  CH3(CH2)3CH2CH3
                  II.
                  (CH3)2CHCH2CH3
                  III.
                  CH3CH(CH3)CH2CH2CH3
                  • I and II only

                  • I and III only

                  • II and III only

                  • I, II and III

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                  111 mark

                  What is the correct condensed structural formula for 2,2-dibromo-4-methylhexane?

                  • CH3CBr2CH(CH3)CH2CH2CH3

                  • CH3CHBrCBr(CH3)CH2CH2CH3

                  • CH3CBr2CH2CH(CH3)CH2CH3

                  • CH3CHBrCH(CH3)CHBrCH2CH3

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                  121 mark

                  What is the correct IUPAC name for the molecule shown?

                  10-1-h-q4-mcqs-ib-chemistry

                  • ethoxyethane

                  • methoxyethane

                  • propanone

                  • propanal

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                  131 mark

                  Which of the molecules shown below is not an isomer of pentan-2-ol?

                  • pentan-1-ol

                  • 2-methylbutan-2-ol

                  • 2-methylpentan-2-ol

                  • pentan-3-ol

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                  141 mark

                  Which of the following pairs are functional group isomers?

                  I.
                  CH3CH(OH)CH2CH2CH3 and CH3CH2CH(OH)CH2CH3
                  II.
                  CH3CH2CH2COOH and HCOOCH2CH2CH3
                  III.
                  CH3CH2CH2OH and CH3OCH2CH3
                  • I and II only

                  • I and III only

                  • II and III only

                  • I, II and III

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                  151 mark

                  What is the correct name of the following molecule using IUPAC rules?

                  10-1-h-q8-mcqs-ib-chemistry

                  • propyl methanoate

                  • methyl propanoate

                  • methoxypropane

                  • butoxymethanal

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                  161 mark

                  What types of isomerism can the following molecule show?

                  10-1-h-q9-mcqs-ib-chemistry

                  I.
                  Branch-chain
                  II.
                  Positional 
                  III.
                  Functional group
                  • I and II only

                  • I and III only

                  • II and III only

                  • I, II and III

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                  17
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                  1 mark

                  How many dimethyl cyclopentane isomers are disubstituted and have the cyclopentane structure? 

                  • 3

                  • 4

                  • 5

                  • 6

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                  18
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                  1 mark

                  Which structure is the correct cis trans isomer of trans-1,2-dibromocyclobutane? 

                  • 071e94cd-60a9-4a2d-ae93-5b18d9c18acb

                     

                  • IB 20.3 MCQ H Option B

                     

                  • IB 20.3 MCQ H Option C

                     

                  • 69b446c6-efd4-42a0-b85c-f2145b750414

                     

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                  19
                  Sme Calculator
                  1 mark

                  Which molecule has a chiral centre? 

                  • CH3OCH2CH3

                  • CH3CH2CHO

                  • CH3CH(NH2)CH3

                  • CH3CH(OH)CH2CH3

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                  20
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                  1 mark

                  Arthrinin-F is a compound isolated from fungus.

                  1-1

                  What is the correct number of chiral carbons in the structure?

                  • 2

                  • 3

                  • 4

                  • 5

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