NATIONAL QUALIFICATIONS CURRICULUM SUPPORT
Chemistry
Consumer Chemistry
Predicting Physical Properties of
Molecules from Functional Groups
[HIGHER]
2 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
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© Learning and Teaching Scotland 2010
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CONSUMER CHEMISTRY (H, CHEMISTRY) 3
© Learning and Teaching Scotland 2010
Contents
Introduction 4
Questions 5
Answers 19
INTRODUCTION
4 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Introduction
This resource supports the Consumer Chemistry unit of the revised Higher
Chemistry. The resource has the following purposes:
1. to allow students to become familiar with identifying functional groups
within everyday molecules, some of which have complex structures
2. to enable students to relate intermolecular forces to the functional
groups present
3. to enable students to explain the physical properties of molecules based
on the functional groups present.
QUESTIONS
CONSUMER CHEMISTRY (H, CHEMISTRY) 5
© Learning and Teaching Scotland 2010
Questions
Question 1
Benzaldehyde is an aromatic compound with an almond-like smell, which is
used in flavourings and perfumes.
Circle and name the functional group on the benzaldehyde molecule below.
C
H
O
Benzaldehyde
QUESTIONS
6 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 2
Cholesterol is an important molecule present in the human body. However,
high levels of a certain type of cholesterol in the blood are linked with
illnesses such as heart disease and strokes.
CH2
CH
CH2
CH2
C
C
CH CH2
CH
CH
CH2CH2
C
CH
CH2
CH2
CH
HO
CH3 CH3
CH
CH3
CH2 CH2 CH2 CH2
Cholesterol
CH3
CH3
(a) Identify the two circled functional groups on the cholesterol molecule .
(b) Explain why this compound has a high boiling point.
QUESTIONS
CONSUMER CHEMISTRY (H, CHEMISTRY) 7
© Learning and Teaching Scotland 2010
Question 3
β-carotene is a member of a family of chemicals called the carotenoids. It is responsible for the orange colour in many fruits
and vegetables, including carrots.
CH2
CH2
CH2 C
C
C
CH3
CH3
CH3
CH CH C
CH3
CH CH CH C
CH3
CH CH CH CH C
CH3
CH CH CH C
CH3
CH CH C
C CH2
CH2
CH2C
CH3
CH3
CH3
-carotene
(a) Which functional group is present throughout the structure of β-carotene?
(b) Is the carbon-to-carbon double bond polar or non-polar?
(c) Which type of intermolecular forces will exist between β -carotene molecules?
QUESTIONS
8 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 4
The vanilla bean produces a compound called vanillin , which is used as a
flavouring additive in sweet foods such as ice cream.
C
H
O
OH
O CH3
Vanillin
(a) Identify two functional groups present in vanillin.
(b) What is the strongest type of intermolecular force present between
molecules of vanillin?
QUESTIONS
CONSUMER CHEMISTRY (H, CHEMISTRY) 9
© Learning and Teaching Scotland 2010
Question 5
The compounds shown below are active ingredients in over -the-counter
drugs. Aspirin is used as an analgesic (to relieve pain) and as an antipyretic
(to reduce elevated body temperatures). Ibuprofen is used as an anti -
inflammatory agent (to counteract swelling or inflammation of the joints, skin
and eyes).
C
OHO
O
C
CH3
O
Aspirin(acetylsalicylic acid)
CH2CH
CH3
C
O
OH
CHCH3
CH3
Ibuprofen
(a) Which functional group is present in both drug molecules?
(b) Which functional group is present in aspirin but not in ibuprofen?
QUESTIONS
10 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 6
The two compounds shown below have similar molecular mass.
HO N C
O
CH3
Paracetamol
H
C
CH2
CH
CH2
CH
CO
CH3
C
CH2 CH3
Carvone
Molecular mass = 151 amu Molecular mass = 150 amu
(amu = atomic mass units)
(a) Identify two different types of functional group present in paracetamol.
(b) Identify two different types of functional group present in carvone.
(c) In terms of intermolecular forces, explain why the melting point of
paracetamol (168°C) is significantly higher than that of carvone (25°C).
QUESTIONS
CONSUMER CHEMISTRY (H, CHEMISTRY) 11
© Learning and Teaching Scotland 2010
Question 7
Capsaicin and zingerone are natural strong-smelling compounds found in
chilli pepper and ginger, respectively.
CH2 CH2 C
O
CH3
OCH3Zingerone
HO
OCH3
CH2 N C
O
CH2 CH2 CH2 CH2 CH CH CH
CH3
CH3
Capsaicin
HO
H
(a) Identify the two circled functional groups in zingerone.
(b) Identify the three circled functional groups in capsaicin.
QUESTIONS
12 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 8
Oil of wintergreen is an essential oil that is used in aromatherapy massage
blends for the joints and muscles. Methyl salicylate is the active ingredient of
oil of wintergreen.
OH
C
O
O
CH3
methyl salicylate
(a) Identify the two circled functional groups present in methyl salicylate.
(b) Explain whether the hydroxyl group contains a polar or a non -polar
bond.
QUESTIONS
CONSUMER CHEMISTRY (H, CHEMISTRY) 13
© Learning and Teaching Scotland 2010
Question 9
Lycopene (C40H56) is the red pigment found in tomatoes and other red fruits and vegetables.
CH CH CH C
CH3
CH CH CH C
CH3
CH CH CH CH C
CH3
CH CH CH C
CH3
CH CH CH
Lycopene
C
CH3
CH2 CH2C
CH3
CH2CH2CHC
CH3
H3C CH C
CH3
CH3
Astaxanthin (C40H52O4) is a pink pigment found in salmon, trout, lobster and shrimp.
C
CH
CH2 C
C
C
CH3
CH3
CH CH C
CH3
CH CH CH C
CH3
CH CH CH CH C
CH3
CH CH CH C
CH3
CH CH C
C C
CH
CH2C
CH3
CH3
CH3
Astaxanthin O
OHHO
O CH3
(a) Which functional group is found repeatedly throughout the structure of lycopene?
(b) Name two additional functional groups that are found in the structure of astaxanthin.
(c) Explain why astaxanthin (215°C) has a higher boiling point than lycopene (172°C).
QUESTIONS
14 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 10
Tetracycline is an antibiotic that is widely used as an alternative treatment for
patients who are allergic to penicillin. It prevents the growth of invading
bacteria, allowing the body’s own immune system to fight off infection.
C
C
CH
C
C
CH2
CH
C
C
C
C
CH
OH O
HO CH3
OH
OH
O
OH
C
O
N
N
CH3CH3
Tetracycline
H
H
Identify four different types of functional group on the tetracycline structure.
QUESTIONS
CONSUMER CHEMISTRY (H, CHEMISTRY) 15
© Learning and Teaching Scotland 2010
Question 11
L-tyrosine is an important building block in the formation of almost all
proteins in the body.
CH
NH2
C
O
OH
HO CH2
L-tyrosine
Identify three functional groups present in its structure.
QUESTIONS
16 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 12
Alanine (2-aminopropanoic acid) is found in meat, fish, seafood and dairy
products.
CH
CH3
C
O
OH
N
alanine
H
H
Which functional groups are present in an alanine molecule?
A. Aldehyde, amine and hydroxyl
B. Ketone, amine and hydroxyl
C. Carboxyl and amine
D. Amino acid and hydroxyl
QUESTIONS
CONSUMER CHEMISTRY (H, CHEMISTRY) 17
© Learning and Teaching Scotland 2010
Question 13
Aspirin and ibuprofen are common over-the-counter drugs.
C
OHO
O
C
CH3
O
Aspirin(acetylsalicylic acid)
CH2CH
CH3
C
O
OH
CHCH3
CH3
Ibuprofen
Identify the term that can be applied to aspirin but not to ibuprofen.
A. Aldehyde
B. Ketone
C. Carboxylic acid
D. Ester
QUESTIONS
18 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 14
Cyclohexyne is used in insect repellents.
cyclohexyne
C
C
C
C
C
C
H H
H
H H
H
H
H
Which of the following would be the best solvent for dissolving cycloh exyne?
A. Hexane
B. Hexanal
C. Hexanol
D. Hexanone
ANSWERS
CONSUMER CHEMISTRY (H, CHEMISTRY) 19
© Learning and Teaching Scotland 2010
Answers
Question 1
Benzaldehyde is an aromatic compound with an almond-like smell, which is
used in flavourings and perfumes.
Circle and name the functional group on the benzaldehyde molecule below.
C
H
O
Benzaldehyde
Carbonyl group
ANSWERS
20 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 2
Cholesterol is an important molecule present in the human body. However,
high levels of a certain type of cholesterol in the blood are linked with
illnesses such as heart disease and strokes.
CH2
CH
CH2
CH2
C
C
CH CH2
CH
CH
CH2CH2
C
CH
CH2
CH2
CH
HO
CH3 CH3
CH
CH3
CH2 CH2 CH2 CH2
Cholesterol
CH3
CH3
(a) Identify the two circled functional groups on the cholesterol molecule
Hydroxyl group and carbon-to-carbon double bond.
(b) Explain why this compound has a high boiling point.
Hydrogen bonding exists between the polar hydroxyl groups on
cholesterol molecules. Extra energy is required to overcome these
strong intermolecular forces of attraction, and therefore the boiling
point is high.
Additionally, cholesterol is a large molecule containing a large number
of electrons, which leads to relatively strong London forces existing
between cholesterol molecules. As more energy is therefore required to
separate the molecules, the boiling point is higher.
Hydroxyl group
Carbon-to-carbon double bond
ANSWERS
CONSUMER CHEMISTRY (H, CHEMISTRY) 21
© Learning and Teaching Scotland 2010
Question 3
β-carotene is a member of a family of chemicals called the carotenoids. It is
responsible for the orange colour in many fruits and vegetables, including
carrots.
CH2
CH2
CH2 C
C
C
CH3
CH3
CH3
CH CH C
CH3
CH CH CH C
CH3
CH CH CH CH C
CH3
CH CH CH C
CH3
CH CH C
C CH2
CH2
CH2C
CH3
CH3
CH3
-carotene
(a) Which functional group is present throughout the struc ture of β-
carotene?
Carbon-to-carbon double bond.
(b) Is the carbon-to-carbon double bond polar or non-polar?
Both atoms have the same electronegativity value (2.5) therefore the
bonds are non-polar covalent.
(c) Which type of intermolecular forces will exis t between β-carotene
molecules?
London dispersion forces as the molecule does not contain polar bonds.
ANSWERS
22 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 4
The vanilla bean produces a compound called vanillin , which is used as a
flavouring additive in sweet foods such as ice cream.
C
H
O
OH
O CH3
Vanillin
(a) Identify two functional groups present in vanillin.
Hydroxyl group and carbonyl group (aldehyde) .
(b) What is the strongest type of intermolecular force present between
molecules of vanillin?
Hydrogen bonding due to the presence of hydroxyl groups.
Carbonyl group
(aldehyde)
Hydroxyl group
ANSWERS
CONSUMER CHEMISTRY (H, CHEMISTRY) 23
© Learning and Teaching Scotland 2010
Question 5
The compounds shown below are active ingredients in over -the-counter
drugs. Aspirin is used as an analgesic (to relieve pain) and as an antipyretic
(to reduce elevated body temperatures). Ibuprofen is used as an anti-
inflammatory agent (to counteract swelling or inflammation of the joints, skin
and eyes).
C
OHO
O
C
CH3
O
Aspirin(acetylsalicylic acid)
CH2CH
CH3
C
O
OH
CHCH3
CH3
Ibuprofen
(a) Which functional group is present in both drug molecules?
Carboxyl group.
(b) Which functional group is present in aspirin but not in ibuprofen?
Ester link.
Carboxyl group Carboxyl group
Ester link
ANSWERS
24 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 6
The two compounds shown below have similar molecular mass.
HO N C
O
CH3
Paracetamol
H
C
CH2
CH
CH2
CH
CO
CH3
C
CH2 CH3
Carvone
Molecular mass = 151 amu Molecular mass = 150 amu
(amu = atomic mass units)
(a) Identify two different types of functional group present in paracetamol.
Hydroxyl group and amide link
(b) Identify two different types of functional group present in carvone.
Carbonyl group and carbon-to-carbon double bond.
(c) In terms of intermolecular forces, explain why the melting point of
paracetamol (168°C) is significantly higher than that of carvone (25°C).
Paracetamol contains the hydroxyl group, therefore hydrogen bonding
exists between its molecules. Permanent dipole–permanent dipole
interactions form between carvone molecules. Hydrogen bonds are an
unusually strong type of permanent dipole–permanent dipole
interactions, so more energy is required to overcome the intermolecular
forces of attraction between paracetamol molecules, and therefore
paracetemol has a higher boiling point than carvone.
Carbon-to-carbon
double bond
Amide link
Hydroxyl group
Carbonyl group
ANSWERS
CONSUMER CHEMISTRY (H, CHEMISTRY) 25
© Learning and Teaching Scotland 2010
Question 7
Capsaicin and zingerone are natural strong-smelling compounds found in
chilli pepper and ginger, respectively.
CH2 CH2 C
O
CH3
OCH3Zingerone
HO
OCH3
CH2 N C
O
CH2 CH2 CH2 CH2 CH CH CH
CH3
CH3
Capsaicin
HO
H
(a) Identify the two circled functional groups in zingerone.
Hydroxyl group and carbonyl group.
(b) Identify the three circled functional groups in Capsaicin.
Hydroxyl group, amide link and carbon-to-carbon double bond.
Amide link
Carbon-to-carbon
double bond
Hydroxyl group
Carbonyl group
ANSWERS
26 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 8
Oil of wintergreen is an essential oil that is used in aromatherapy massage
blends for the joints and muscles. Methyl salicylate is the active ingredient of
oil of wintergreen.
OH
C
O
O
CH3
methyl salicylate
(a) Identify the two circled functional groups present in methyl salicylate.
Ester link and hydroxyl group.
(b) Explain whether the hydroxyl group contains a polar or a non -polar
bond.
The bond is polar because of the difference in electronegativity between
oxygen (3.5) and hydrogen (2.2).
ANSWERS
CONSUMER CHEMISTRY (H, CHEMISTRY) 27
© Learning and Teaching Scotland 2010
Question 9
Lycopene (C40H56) is the red pigment found in tomatoes and other red fruits and vegetables.
CH CH CH C
CH3
CH CH CH C
CH3
CH CH CH CH C
CH3
CH CH CH C
CH3
CH CH CH
Lycopene
C
CH3
CH2 CH2C
CH3
CH2CH2CHC
CH3
H3C CH C
CH3
CH3
Astaxanthin (C40H52O4) is a pink pigment found in salmon, trout, lobs ter and shrimp.
C
CH
CH2 C
C
C
CH3
CH3
CH CH C
CH3
CH CH CH C
CH3
CH CH CH CH C
CH3
CH CH CH C
CH3
CH CH C
C C
CH
CH2C
CH3
CH3
CH3
Astaxanthin O
OHHO
O CH3
(a) Which functional group is found repeatedly throughout the structure of lycopene?
Carbon-to-carbon double bond.
(b) Name two additional functional groups that are found in the structure of astaxanthin.
Carbonyl group (ketone) and hydroxyl group.
(c) Explain why astaxanthin (215°C) has a higher boiling point than lycopene (172°C).
Astaxanthin contains several polar groups and forms hydrogen bonding and other permanent dipole –permanent dipole
attractions between molecules. Lycopene contains no polar bonds, therefore only has London dispersion forces between
molecules. More energy is required to break the stronger attractive forces between astaxanthin molecules, so its boiling
point is higher.
ANSWERS
28 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 10
Tetracycline is an antibiotic that is widely used as an alternative treatment for
patients who are allergic to penicillin. It prevents the growth of invading
bacteria, allowing the body’s own immune system to fight off infection.
C
C
CH
C
C
CH2
CH
C
C
C
C
CH
OH O
HO CH3
OH
OH
O
OH
C
O
N
N
CH3CH3
Tetracycline
H
H
Identify four different types of functional group on the tetracycline structure.
Amino group, carbonyl group, hydroxyl group and carbon-to-carbon double
bond.
ANSWERS
CONSUMER CHEMISTRY (H, CHEMISTRY) 29
© Learning and Teaching Scotland 2010
Question 11
L-tyrosine is an important building block in the formation of almost all
proteins in the body.
CH
NH2
C
O
OH
HO CH2
L-tyrosine
Identify three functional groups present in its structure.
Amino group, hydroxyl group and carboxyl group.
ANSWERS
30 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 12
Alanine (2-aminopropanoic acid) is found in meat, fish, seafood and dairy
products.
CH
CH3
C
O
OH
N
alanine
H
H
Which functional groups are present in an alanine molecule?
A. Aldehyde, amine and hydroxyl
B. Ketone, amine and hydroxyl
C. Carboxyl and amine
D. Amino acid and hydroxyl
ANSWERS
CONSUMER CHEMISTRY (H, CHEMISTRY) 31
© Learning and Teaching Scotland 2010
Question 13
Aspirin and ibuprofen are common over-the-counter drugs.
C
OHO
O
C
CH3
O
Aspirin(acetylsalicylic acid)
CH2CH
CH3
C
O
OH
CHCH3
CH3
Ibuprofen
Identify the term that can be applied to aspirin but not to ibuprofen.
A. Aldehyde
B. Ketone
C. Carboxylic acid
D. Ester
ANSWERS
32 CONSUMER CHEMISTRY (H, CHEMISTRY)
© Learning and Teaching Scotland 2010
Question 14
Cyclohexyne is used in insect repellents.
cyclohexyne
C
C
C
C
C
C
H H
H
H H
H
H
H
Which of the following would be the best solvent for dissolving cyclohexyne?
A. Hexane
B. Hexanal
C. Hexanol
D. Hexanone
Cyclohexyne is a non-polar molecule, and therefore hexane (a non-polar
solvent) will dissolve it best.