CIE AS Chemistry

Topic Questions

ASChemistryCIETopic Questions4. Analysis4.1 Analytical Techniques

Syllabus Edition

First teaching 2020

Last exams 2024

|

4.1 Analytical Techniques

DownloadView
Easy
Medium
Hard
Easy
Medium
Hard
11 mark

Which of the following corresponds to the base peak in a mass spectrum?

  • The peak corresponding to the ion with lowest m/e.

  • The peak corresponding to the molecular ion.

  • The peak corresponding to any ion formed by the fragmentation of the molecule.

  • The peak corresponding to the most abundant ion.

Choose your answer

Did this page help you?

21 mark

The diagram shows the structure of ricinoleic acid.

4-1-e-2

Which fragment would produce the tallest peak in the mass spectrum of ricinoleic acid at m/e = 55?

  • CH2CO2+

  • CH═CHCHOH+

  • C4H7+

  • COOH+

Choose your answer

Did this page help you?

31 mark

In a mass spectrometer, the ions are separated.

Which of the following species will be deflected to the greatest extent?

  • 37Na+

  • 35Na+

  • 37Na

  • 35Na2+

Choose your answer

Did this page help you?

41 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.

Choose your answer

Did this page help you?

51 mark

A sample of silicon contains the following isotopes

Isotope

Percentage abundance

28Si

81.21

29Si

14.10

30Si

4.69

What is the relative atomic mass of silicon in this sample, to 1dp?

  • 29.8

  • 29.0

  • 28.2

  • 28.0

Choose your answer

Did this page help you?

61 mark

Chlorine exists as two isotopes with mass numbers 35 and 37. A sample of chlorine contains 75.3% of chlorine-35 atoms.

What is the relative atomic mass of chlorine in this sample, to 2dp?

  • 35.16

  • 36.00

  • 35.49

  • 35.00

Choose your answer

Did this page help you?

71 mark

A sample of neon contains the following isotopes

Isotope

Percentage abundance

20Ne

90.92

21Ne

0.26

22Ne

8.82

What is the relative atomic mass of neon in this sample, to 2dp?

  • 21.00

  • 20.18

  • 20.09

  • 20.00

Choose your answer

Did this page help you?

81 mark

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

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

 

Ion

m/e

A

N(35Cl)3+

119

B

N(35Cl)237Cl+

121

C

N35Cl(37Cl)2+

123

D

N(37Cl)2+

125

Choose your answer

Did this page help you?

91 mark

The mass spectrum of silicon is shown below.

4-1-e-9

What is the best estimate for the relative atomic mass of silicon in this sample?

  • 29.0

  • 28.8

  • 28.3

  • 28.0

Choose your answer

Did this page help you?

101 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

Choose your answer

Did this page help you?

11 mark

Data from the mass spectrum of a sample of pure iron is shown in the table below.

m/e

Relative peak height

28

0.1

54

6.3

56

100.0

57

2.4

58

0.3

Which species is most likely to cause the peak at m/e = 28?

  • 84Sr3+

  • 28Si+

  • 56Fe2+

  • 28Fe+

Choose your answer

Did this page help you?

21 mark

Two stable isotopes of bromine have relative masses of 79 and 81. 

Which is the correct pattern of peaks in the mass spectrum of molecular bromine?

  • b0gDg7dh_4-1-h-2a

  • 4-1-h-2b

  • 4-1-h-2c

  • 4-1-h-2d

Choose your answer

Did this page help you?

31 mark

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

4-1-h-3a

4-1-h-3b

4-1-h-3c

Which of the following features of the three compounds A, B and C shows the molecular formula is C4H10O?

  • 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

Choose your answer

Did this page help you?

41 mark

The infrared spectrum below shows an unknown compound.

4-1-h-4

 

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?

  • 4-1-h-4a

  • 4-1-h-4b

  • 4-1-h-4c

  • 4-1-h-4d

Choose your answer

Did this page help you?

51 mark

The diagram shows an infrared spectrum of a compound.

4-1-h-5

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

Choose your answer

Did this page help you?

61 mark

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

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

  • 4-1-h-6a

  • 4-1-h-6b

  • 4-1-h-6c

  • 4-1-h-6d

Choose your answer

Did this page help you?

71 mark

Chlorine exists as two isotopes 35Cl and 37Cl in the ratio 3:1.

Which of the following statements about the molecular ion peaks in the mass spectrum of Cl2 is correct?

  • Peaks at m/e = 70 and 72 in the ratio 3:1

  • Peaks at m/e = 70, 72 and 74 in the ratio 9:3:1

  • Peaks at m/e = 70, 72 and 74 in the ratio 9:6:1

  • Peaks at m/e = 70 and 74 in the ratio 3:1

Choose your answer

Did this page help you?

81 mark

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

Which of the following statements is incorrect?

  • n = 5

  • The compound could contain bromine

  • X and F are monotopic

  • The compound is a fluoride of iodine

Choose your answer

Did this page help you?

91 mark

In the mass spectrum of trifluoroacetic acid, CF3CO2H, intense peaks are observed at m/e = 69 and 45 (base peak) in addition to other peaks. 

The peak at m/e = 69 is accompanied by a peak at m/e = 70, which is about 1.1% the intensity of the peak at m/e = 69. 

Which of the following statements is not supported by this information?

  • C−C bond cleavage occurs

  • Fluorine is monotopic

  • [HO2C]+ is a fragment ion

  • CF3CO2H fragments by sequential loss of F atoms

Choose your answer

Did this page help you?

101 mark

A sample is analysed by mass spectrometry and infrared spectroscopy. The following incomplete 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

Which of the following compounds is demonstrated by this data?

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

  • 4-1-h-10a

  • 4-1-h-10b

  • 4-1-h-10c

  • 4-1-h-10d

Choose your answer

Did this page help you?

11 mark

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

  • (CH3)2CHCH2OH

  • CH3CH(OH)CH2CH2CH3

  • CH3CH2CH2CH2OH

  • CH3CH2CH(OH)CH3

Choose your answer

Did this page help you?

21 mark

Which of the compounds below is not likely to have a fragment ion at m/e = 43 in its mass spectrum?

  • 4-1-m-2a

  • 4-1-m-2b

  • 4-1-m-2c

  • 4-1-m-2d

Choose your answer

Did this page help you?

31 mark

Assuming that chlorine has only two isotopes and hydrogen and carbon as one, how many molecular ion peaks will be shown in the mass spectrum of C4H6Cl4?

  • 5

  • 4

  • 3

  • 2

Choose your answer

Did this page help you?

41 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.

Choose your answer

Did this page help you?

51 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

Choose your answer

Did this page help you?

61 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

Choose your answer

Did this page help you?

71 mark

The infrared spectrum of a compound is shown below.

4-1-m-7

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

Choose your answer

Did this page help you?

81 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

Choose your answer

Did this page help you?

91 mark

Chlorine has two isotopes, 35Cl and 37Cl. 

What is the number of molecular ion peaks in the mass spectrum of a sample of Cl2?

  • 5

  • 4

  • 3

  • 2

Choose your answer

Did this page help you?

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.

Choose your answer

Did this page help you?