Circle and Name the Functional Group on the Benzaldehyde Molecule Below

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.

Benzaldehyde

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 CH2 CH3 CH2 CH2 CH 3 CH3 CH3

HO CH C CH C CH CH CH2 CH2 CH2 CH2 CH3

CH2 C CH CH

CH2 CH CH CH2 2

Cholesterol

(a) Identify the two circled functional groups on the cholesterol molecule.

(b) Explain why this compound has a high boiling point. 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.

CH CH3 3

CH3 CH3 CH2 C CH3 C CH2

CH2 C CH CH C CH CH CH C CH CH CH CH C CH CH CH C CH CH C CH2

CH C CH C CH 2 3 CH3 CH3 2

CH3 -carotene CH3

(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? Question 4

The vanilla bean produces a compound called vanillin, which is used as a flavouring additive in sweet foods such as ice cream.

Vanillin

(a) Identify two functional groups present in vanillin.

(b) What is the strongest type of intermolecular force present between molecules of vanillin?

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).

O OH C

CH CH3 3 O CH3 O C CH C CH3 CH CH2

Aspirin (acetylsalicylic acid) Ibuprofen

(a) Which functional group is present in both drug molecules?

(b) Which functional group is present in aspirin but not in ibuprofen? Question 6

The two compounds shown below have similar molecular mass.

O C C CH

H O CH2 CH2 CH HO N C C CH 3 CH2 CH3

Paracetamol 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).

Question 7

Capsaicin and zingerone are natural strong-smelling compounds found in chilli pepper and ginger, respectively.

HO CH2 CH2 C

CH3 O Zingerone

HO CH2 N C CH2 CH2 CH2 CH2 CH CH CH CH3

CH3 O Capsaicin

(a) Identify the two circled functional groups in zingerone.

(b) Identify the three circled functional groups in capsaicin. 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.

C CH3 O

OH 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. Question 9

Lycopene (C40H56) is the red pigment found in tomatoes and other red fruits and vegetables.

CH3 CH3 CH3 CH3

H3C C CH CH2 CH2 C CH CH CH C CH CH CH C CH CH CH CH C CH CH CH C CH CH CH C CH2 CH2 CH C CH3

Lycopene CH3 CH3 CH3 CH3

Astaxanthin (C40H52O4) is a pink pigment found in salmon, trout, lobster and shrimp.

CH O CH3 3 CH CH C C 3 3 CH3 C CH2

HO CH C CH CH C CH CH CH C CH CH CH CH C CH CH CH C CH CH C CH OH

CH2 C CH C C 3 CH3 CH3

CH3 Astaxanthin CH3 O (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). 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.

CH3 CH3

HO CH3 N

C CH2 CH OH CH CH C H

C C C N C C C C H OH OH O OH O O

Tetracycline

Identify four different types of functional group on the tetracycline structure.

Question 11

L-tyrosine is an important building block in the formation of almost all proteins in the body.

HO CH2 CH C OH

L-tyrosine

Identify three functional groups present in its structure. Question 12

Alanine (2-aminopropanoic acid) is found in meat, fish, seafood and dairy products.

CH3 H O N CH C

H OH alanine

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

Question 13

Aspirin and ibuprofen are common over-the-counter drugs.

O OH C

CH O CH3 CH3 3 O C CH C CH3 CH CH2 O OH

Identify the term that can be applied to aspirin but not to ibuprofen.

A. Aldehyde B. Ketone C. Carboxylic acid D. Ester Question 14

Cyclohexyne is used in insect repellents.

H H H C H C C

H C C C H H H cyclohexyne

Which of the following would be the best solvent for dissolving cyclohexyne?

A. Hexane B. Hexanal C. Hexanol D. Hexanone 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.

O Carbonyl group C H

Benzaldehyde

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 CH2 CH3 CH2 CH2 CH 3 CH3 CH3

HO CH C CH C CH CH CH2 CH2 CH2 CH2 CH3

CH2 C CH CH

CH2 Hydroxyl group CH CH CH2 2

Carbon-to-carbon double bond Cholesterol

(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. 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.

CH CH3 3 CH CH CH2 C 3 3 CH3 C CH2

CH2 C CH CH C CH CH CH C CH CH CH CH C CH CH CH C CH CH C CH2

CH2 C CH C CH 3 CH3 CH3 2

CH3 -carotene CH3

(a) Which functional group is present throughout the structure 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 exist between β-carotene molecules? London dispersion forces as the molecule does not contain polar bonds.

Question 4

The vanilla bean produces a compound called vanillin, which is used as a flavouring additive in sweet foods such as ice cream.

O Hydroxyl group

Vanillin Carbonyl group (aldehyde)

(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. 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).

Carboxyl group Carboxyl group O OH C

CH O CH3 CH3 3 O C CH C CH3 CH CH2 O OH Ester link Aspirin (acetylsalicylic acid) 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. Question 6

The two compounds shown below have similar molecular mass.

Carbon-to-carbon CH3 double bond

Amide link O C C CH

CH CH H O 2 2 Carbonyl group CH HO N C C CH3 CH2 CH3

Hydroxyl group Paracetamol 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. Question 7

Capsaicin and zingerone are natural strong-smelling compounds found in chilli pepper and ginger, respectively.

Carbonyl group O

HO CH2 CH2 C

CH3 O Zingerone Hydroxyl group Carbon-to-carbon double bond

HO CH2 N C CH2 CH2 CH2 CH2 CH CH CH CH3

CH3 O Capsaicin

Amide link

(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. 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.

C CH3 O

OH 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). Question 9

Lycopene (C40H56) is the red pigment found in tomatoes and other red fruits and vegetables.

CH3 CH3 CH3 CH3

H3C C CH CH2 CH2 C CH CH CH C CH CH CH C CH CH CH CH C CH CH CH C CH CH CH C CH2 CH2 CH C CH3

Lycopene CH3 CH3 CH3 CH3

Astaxanthin (C40H52O4) is a pink pigment found in salmon, trout, lobster and shrimp.

CH O CH3 3 CH CH C C 3 3 CH3 C CH2

HO CH C CH CH C CH CH CH C CH CH CH CH C CH CH CH C CH CH C CH OH

CH2 C CH C C 3 CH3 CH3

CH3 Astaxanthin CH3 O

(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. 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.

CH3 CH3

HO CH3 N

C CH2 CH OH CH CH C H

C C C N C C C C H OH OH O OH O O

Tetracycline

Identify four different types of functional group on the tetracycline structure. Amino group, carbonyl group, hydroxyl group and carbon-to-carbon double bond.

Question 11

L-tyrosine is an important building block in the formation of almost all proteins in the body.

HO CH2 CH C OH

L-tyrosine

Identify three functional groups present in its structure. Amino group, hydroxyl group and carboxyl group. Question 12

Alanine (2-aminopropanoic acid) is found in meat, fish, seafood and dairy products.

CH3 H O N CH C

H OH alanine

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 Question 13

Aspirin and ibuprofen are common over-the-counter drugs.

O OH C

O CH3 CH CH3 3 C O

CH C CH3 CH CH2 O OH

Identify the term that can be applied to aspirin but not to ibuprofen.

A. Aldehyde

B. Ketone

C. Carboxylic acid

D. Ester Question 14

Cyclohexyne is used in insect repellents.

H H H C H C C

H C C C H H H cyclohexyne

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.