Chap 2 - Carbon Compound

ORGANIC
CHEMISTRY

THEME 2

This theme discusses basic organic substances around us, classification of hydrocarbon
compounds based on homologous series, physical properties, and chemical properties.
Knowledge on preparation methods and chemical properties of substances are important in the
application of processing and production of commercial and industrial substances.

61

2Chapter

CARBON
COMPOUND

Key W ds
• Alcohol
• Alkane
• Alkene
• Alkyne
• Carboxylic acid
• Ester
• Homologous series
• Hydrocarbon
• Inorganic carbon compounds
• Isomers
• Non hydrocarbon
• Organic carbon compounds
• Saturated hydrocarbon
• Unsaturated hydrocarbon

What will you learn?

2.1 Types of carbon compound
2.2 Homologous series
2.3 Chemical properties and interconversion of

compounds between homologous series
2.4 Isomers and naming based on IUPAC nomenclature

62

Bulletin

One of the unique things that is part of the lives of the

ethnic groups in Sabah and Sarawak is a drink called

tuak. Do you know that tuak is a drink that is made

by fermenting certain foods such as tapioca, rice or

glutinous rice with yeast? Tuak is an important

element during local rituals and special events like

the annual ceremonies of the Ibans, Melanaus,

Dayaks and other ethnic sub-groups. Normally, tuak

Source: (https://loanstreet.com.my/ is served to guests as a welcome drink during the
ms/pusat-pembelajaran/
Kaamatan and Gawai Festivals that are celebrated

pesta-kaamatan-hari-gawai) after the harvest season every year.

In science, what is the chemical reaction involved in the production of tuak? The
answer is quite easy. Tuak is a type of drink that is prepared through a process
called fermentation. Fermentation involves the use of yeast to break down large
molecules of carbohydrates, such as sucrose or glucose, into smaller molecules
like ethanol, C2H5OH. The yeast secretes the enzyme called zymase that
transforms glucose into ethanol, C2H5OH and carbon dioxide, CO2.

C6H12O6(aq) Zymase 2C2H5OH(l) + 2CO2(g)

Glucose Ethanol(14-15%) Carbon dioxide

It is important to note that tuak can be harmful because it can cause intoxication,
hallucinations and induce vomiting if it is consumed in large quantities.

What is the chemical What is the source of raw materials
that forms the major for the petrochemical industry?
composition in liquid
disinfectant? What are the chemicals
that induce the smell
of fruits and perfumes?

63

Theme 2 Organic Chemistry

2.1 TYPES OF CARBON COMPOUNDS

• Carbon transfers from the atmosphere to living organisms Standards
on earth and back to the atmosphere. Based on Figure 2.1,
can you explain what process has taken place? Pupils are able to:
2.1.1 understand carbon compounds.
2.1.2 explain sources of hydrocarbon.

Form 2 Science:
Carbon Cycle.

Photosynthesis Smoke from • Early chemists defined organic carbon
factories compounds as compounds originating
animal and vehicles from animals or plants (living things),
Organic respiration such as petroleum, carbohydrate,
carbon protein, fat and urea.
Decay of
organisms • Nowadays, organic compounds
Dead organisms also include compounds of natural
and waste products ingredients that are synthesised in the
laboratory. Examples include plastics,
perfumes, detergents and medicines.

Figure 2.1 Carbon cycle

What are carbon compounds? Carbon Compounds

• Carbon compounds are Organic compounds Inorganic compounds
compounds that contain carbon Compounds originating Compounds originating
as their constituent element. from living things that from non-living materials
contain the carbon element such as oxides of carbon,
• There are two types of bonded covalently with carbonate compounds
carbon compounds: other elements such as and cyanide compounds.
(i) Organic compounds hydrogen, nitrogen, sulphur
(ii) Inorganic compounds and phosphorus.

Covalent bond

C Carbon atom • In our daily lives, the word organic carries
different meanings.
• Organic food is grown without using pesticides,
synthetic fertilisers and without genetic
modification (GMO).
• Organic beef, poultry, eggs and dairy products
are made from animals that are free from
antibiotics or growth hormones.

64

Carbon Compound Chapter 2

Hydrocarbon and Non Hydrocarbon

• Organic compounds are divided into hydrocarbons and non hydrocarbons.

Hydrocarbon Organic compounds containing only hydrogen and carbon.

Non Hydrocarbon Organic compounds containing carbon and hydrogen and other
elements, such as oxygen, nitrogen, phosphorus or halogens.

• Table 2.1 shows examples of hydrocarbons and non hydrocarbons.

Table 2.1 Examples of hydrocarbons and non hydrocarbons

Organic compounds Composition Type
Non hydrocarbon
Protein Carbon, hydrogen, nitrogen, oxygen

Petrol Carbon, hydrogen Hydrocarbon

Starch Carbon, hydrogen, oxygen Non hydrocarbon

Fat Carbon, hydrogen, oxygen Non hydrocarbon

Natural gas Carbon, hydrogen Hydrocarbon

Alcohol Carbon, hydrogen, oxygen Non hydrocarbon

• Hydrocarbons are classified into saturated and unsaturated hydrocarbons based on the types of
their covalent bonds.

Saturated hydrocarbon Hydrocarbons containing only single bonds between carbon atoms.

Unsaturated Hydrocarbons containing at least one double bond or triple bond
hydrocarbon between carbon atoms.

• Table 2.2 shows examples of structural formulae of saturated and unsaturated hydrocarbons.

Table 2.2 Examples of structural formulae of saturated and unsaturated hydrocarbons

Saturated hydrocarbon Unsaturated hydrocarbon

HHH HHH H

H CCC H H CCC H H CCC H

HHH H H

Single bonds between Double bond between Triple bond between
carbon atoms carbon atoms carbon atoms

Bab 10/2 Nota3 B02-65
Carbon Compound: Revision on Covalent Bond of Saturatedhttp://kubupublication.com.my/Kimia/Tingkatan5/Nota3.pdf
Homologous series Hydrocarbons and Unsaturated Hydrocarbons
on page 72. https://bit.ly/kpkt5n3

65

Theme 2 Organic Chemistry 2A

A ctivity
Carry out the activity in pairs.
1. Classify the following substances into organic or inorganic compounds:
(a) EPLerthoadapn(aIonIio)clc,aaCcrib3dHo,n7COaHtHe3,C P O b COOH3 ((bd)) CGalurbcoosne,dCio6xHid12eO, 6C O 2
(c)
(e)

2. State the term for each of the following statements:
(a) Compounds containing the carbon element.
(b) Hydrocarbons possessing only single bonds.
(c) Organic compounds containing only carbon and hydrogen.
(d) Carbon compounds derived from living things.
(e) Hydrocarbons possessing double or triple bonds between carbon atoms.

Sources of Hydrocarbons • The van der Waals force
between molecules gets
• The main source of hydrocarbons is petroleum or crude oil. stronger as the molecule
• Petroleum is formed from the remains of plants and animals size increases.
that perished at the bottom of the ocean, millions of years ago.
• Petroleum is a mixture of simple or long-chain hydrocarbons. • The boiling point of
• Petroleum cannot be used before processing. It needs to be hydrocarbons increases
refined into its constituents through a distillation process. as the molecule size
• The two stages of oil refining are fractional distillation increases because more
and cracking. energy is needed to
overcome the force.

Fractional The fractions of hydrocarbons in petroleum are separated at different
distillation temperatures according to the size of the hydrocarbons.
Long chain hydrocarbons are cracked into smaller molecules at a high
Cracking temperature using a catalyst.

Fractional Distillation

• During the fractional distillation process, petroleum is heated
and streamed into a distillation tower as shown in Figure 2.2.
• The fractions in petroleum can be separated because each
fraction of the hydrocarbons has its own boiling point.
• Hydrocarbons with a lower boiling point will vaporise first, and
then rise to the top of the tower before condensing and separating.
• Hydrocarbons with a higher boiling point are collected at the
bottom of the tower and will condense into liquid.
• There are two main uses of hydrocarbon compounds derived
from fractional distillation:
Photograph 2.1 Petroleum fractional (a) As fuels.
distillation process at an oil refinery (b) As raw materials for the petrochemical industry.

66

Carbon Compound Chapter 2

Petroleum gas Cooking gas
C1 − C4 <40 °C

Small molecules Petrol Fuel for
• Low boiling point motor vehicles
• Bright colour
• Highly combustible C5 − C9 40 °C − 75 °C
• Less viscous

Naphtha Raw materials for
C5 − C10 75 °C − 150 °C petrochemical
industry

Kerosene Fuel for aircra s

C10 − C16 160 °C − 250 °C

Big molecules Diesel oil Fuel for heavy
• High boiling point vehicles
• Dark colour such
• Low combustibility C14 − C20 125 °C − 300 °C as buses
• More viscous
Petroleum and lorries

Lubricating oil Lubricating oil and candles

C20 − C50 300 °C − 350 °C

Fuel oil Fuel for
ships and
power
C20 − C70 350 °C − 500 °C stations

Bitumen Road pavements
> C70 >500 °C

Figure 2.2 The process of fractional distillation of petroleum and how the products are used in daily life

Bab 10/2 Video20 B02-67a Source of Bab 10/2 Video21 B02-67b Thermochemistry:
http://kubupublication.com.my/Kimia/Tingkatan5/Video20.html Hydrocarbon http://kubupublication.com.my/Kimia/Tingkatan5/Video21.html Fractional Distillation Calculating the Fuel
of Petroleum Value on page 137.
https://bit.ly/ https://bit.ly/
kpkt5v20 67
kpkt5v21

Theme 2 Organic Chemistry

Cracking

• Cracking is the process of breaking long chain hydrocarbons into smaller hydrocarbons.
• In the cracking process, compounds of large hydrocarbon molecules are heated at a high
temperature and pressure.
• A catalyst such as a mixture of aluminium oxide, Al2O3 and silicon(IV) oxide, SiO2 are usually
used to increase the rate of reaction.
• Cracking process produces:
(i) smaller hydrocarbons such as petrol that is used as fuel.
(ii) alkane and alkene hydrocarbons with shorter chains, to be used as raw materials in the
manufacturing of polymers, medicines, detergents, solvents, fertilizers and many more
useful products.
• The demand for smaller-sized hydrocarbons is higher because it combusts easily, and is used
as fuel.
• The separation of petroleum compounds through Carbon Compound:
fractional distillation cannot meet the high demands Alkanes and alkenes
of smaller sized hydrocarbons. Figure 2.3 shows the on page 73.

examples of a long-chain hydrocarbon cracking reaction.

Example 1: Heat Short chain hydrocarbon molecules

Long chain hydrocarbon molecules C
R
A
C
K
I
N
G

Catalyst

Example 2: Long chain hydrocarbon molecules H Example 3:

HHHHHHH C10H22 → 2C5H10 + H2
HC C C C C C C Decane Pentene Hydrogen

HHHHHHH

HH HHHH H Bab 10/2 Video22 B02-68
CH
H http://kubupublication.com.my/Kimia/Tingkatan5/Video22.html Cracking Reaction

CC HC CCC https://bit.ly/kpkt5v22
HH H HHH

Ethene Pentene

Chemical equation: C7H16 → C2H4 + C5H12

Figure 2.3 Examples of cracking reaction on long-chain hydrocarbons into smaller
hydrocarbon molecules and hydrogen gas

68

Carbon Compound Chapter 2

Laboratory Activity 2A Fractional Distillation of Petroleum Learning Science
Through Inquiry
Aim: To study the fractional distillation of petroleum PAK 21
Materials: Petroleum and cotton
Apparatus: Filter paper, retort stand, thermometer (0 °C − 360 °C), round bottom flask, conical
flask, test tube, Liebig condenser, wire gauze, tripod stand, test tubes, evaporating
dish, porcelain chips, wooden block and Bunsen burner.

Procedure: CAUTION
1. Measure 50 cm3 of petroleum and pour into a round bottom flask. The emitted gases
2. Add one spatula of porcelain chips into the round bottom flask. are flammable.
3. Set up the apparatus as shown in Figure 2.4.
4. Gently heat the petroleum and collect four fractions of petroleum
into four separate test tubes at a temperature range of 30 °C − 80 °C,
80 °C − 120 °C, 120 °C − 160 °C and 160 °C − 200 °C.
5. Observe each fraction of petroleum collected
at different temperatures and record the Thermometer
colour and their viscosity.
6. Place some cotton into an evaporating dish. Round
bottom
flask

7. Put a few drops of the petroleum fraction Water out
collected in the test tube onto the cotton
in the evaporating dish. Liebig
8. Ignite the cotton and observe the colour Petroleum condenser
of the flame and the quantity of soot Porcelain
by placing filter paper above the flame. chips

9. Repeat steps 6 to 8 for petroleum fractions Water in

collected in test tubes 2, 3 and 4. Heat Distillate Wooden
10. Record your observations in the table below. block

Result: Figure 2.4

Test tube Boiling point/°C Colour Viscosity Sootiness
1 30 − 80
2 80 − 120
3 120 − 160
4 160 − 200

Discussion:
1. Why are porcelain chips added into the round bottom flask?
2. Why is a normal thermometer not used in this activity?
3. State the relation between the boiling point of the fraction of petroleum and the following:

(a) its colour,
(b) its viscosity, and
(c) quantity of soot formed after burning.
4. Which fraction of petroleum is most flammable?

Prepare a complete report after carrying out this laboratory activity.

69

Theme 2 Organic Chemistry

What are the alternative sources of hydrocarbon?

Bab 10/2 Video23 B02-70 Bioethanol, Biodiesel
http://kubupublication.com.my/Kimia/Tingkatan5/Video23.html
• Based on our current rate of usage, scientists predict
that most of the petroleum reserves on earth will be and Biogas
https://bit.ly/kpkt5v23
exhausted within 100 years. Therefore, there is a need
for proactive and effective steps to produce alternative
resources to replace petroleum.
• Alternatives to hydrocarbon refer to
alternative energy sources other than
nonrenewable fossil fuels.
• Biomass is organic matter of plants Biomass

and animals. It contains latent energy
derived from the sun.
• These alternative resources are renewable. Biodiesel

Alternative energy sources can be derived Bioethanol
from many chemical processes derived from biomass.
• Figure 2.5 shows examples of alternative energy sources.

A ctivity 2B Biogas

Figure 2.5 Examples of alternative energy sources

PAK 21

Conducting project-based learning to produce bioethanol as an alternative energy source of
hydrocarbon from organic wastes.

Produce bioethanol by using food wastes found in your surroundings. Discuss with your teacher in
order to conduct the activity in the school laboratory.

2.1

1. The following figure shows classifications of carbon compounds.

Carbon Organic Compounds Hydrocarbon Saturated Hydrocarbon
Compounds Inorganic Compounds Non Hydrocarbon Unsaturated Hydrocarbon

Based on the figure above, state the definitions of:
(a) Organic compounds.
(b) Hydrocarbon and non hydrocarbon.
(c) Saturated and unsaturated hydrocarbons.

2. (a) What is meant by cracking?
(b) Copy and complete the following reactions:
(i) C10H22 → C6H14 + …………..
(ii) ………….. → C4H8 + C3H6 + C4H12
(c) Discuss the importance of the cracking process.

70

Carbon Compound Chapter 2

2.2 HOMOLOGOUS SERIES

What is homologous series? Standards

• There are millions of organic compounds known so far. Pupils are able to:
• In order to study the physical properties and chemical 2.2.1 explain homologous series.
2.2.2 construct molecular formulae and
reactions of organic compounds, they are classified into
groups of compounds called the homologous series. structural formulae, and name the
• The homologous series has the following characteristics: members of the homologous series.
2.2.3 describe physical properties of the
i The same general formula. compounds in a homologous series.

ii The same functional group. • A functional group is a group
of atoms bonded to an organic
iii The same chemical properties. molecular compound.

Consecutive members differ by one carbon • The functional group determines
atom and two hydrogen atoms (CH2 or the chemical properties of the
iv relative molecular mass = 14). homologous series.

v Physical properties that gradually change from • Chemical reactions occur at the
one member to the next. functional group.

• The homologous series that we will learn in this chapter Each homologous series consists
are alkane, alkene, alkyne, alcohol, carboxylic acid and of members according to the
ester as shown in Table 2.3. number of carbon atoms, n.

Table 2.3 The homologous series that will be learned in this topic

Homologous General formula Functional Name of Type of
series group functional group organic
compound
Alkane CnH2n+2 , n = 1, 2, 3, … CC Single bond between Saturated
Alkene CnH2n , n = 2, 3, …… carbon atoms hydrocarbon
Alkyne CnH2n-2 , n = 2, 3, …… Unsaturated
Double bond between hydrocarbon
C C carbon atoms Unsaturated
hydrocarbon
Triple bond between Non
C C carbon atoms hydrocarbon

Alcohol CnH2n+1OH, n = 1, 2, … OH Hydroxyl Non
hydrocarbon
Carboxylic CnH2n+1COOH, O Carboxyl
acid n = 0, 1, 2.. CO H Carboxylate Non
Ester CmH2m+1COOCnH2n+1 hydrocarbon
n = 0,1, 2, ...n = 1,2,3… O
CO

71

Theme 2 Organic Chemistry

Molecular Formula, Structural Formula, and the Nomenclature
of Homologous Series Members

• The molecular formula is a chemical formula that shows the type and actual number of atoms of
each element in a molecule.

• The structural formula shows the type of bond and how the atoms in a molecule are bonded to
each other. Example:

Molecular formula Electron arrangement in Structural formula of methane

of methane methane

CH4 H H Represents one pair
HCH HCH of electrons shared to
form a single covalent bond
H H

• The names of the members of each homologous series in a straight chain, according to the IUPAC
nomenclature, consist of two components which are:

Root name Suffix
Represents the homologous series
Represents the number of carbon
atoms in the longest chain

• Table 2.4 shows the root name of the members of homologous series according to the number of
carbon atoms in the longest carbon chain.

Table 2.4 The root name of the members of homologous series

Number of carbon atom 1 2 3 4 5 6 7 8 9 10

Root name Meth Eth Prop But Pent Hex Hept Oct Non Dec

• Table 2.5 shows the suffix of homologous series members.

Table 2.5 Suffix of homologous series members

Homologous series Alkane Alkene Alkyne Alcohol Carboxylic acid Ester
“oate”
Suffix “ane” “ene” “yne” “ol” “oic”

Example:
Write the molecular formula and the name of an alkane with three carbon atoms.
When n = 3
Molecular formula for CnH2n + 2 = C3H2(3) + 2 = C3H8 The nomenclature of
Root name : Prop Suffix: -ane organic compounds is
based on the regulations
set by the International
The name of the alkane with three carbon atoms is propane. Union of Pure and Applied

Chemistry (IUPAC).

72

Carbon Compound Chapter 2

Alkane Saturated e presence of a single covalent
Hydrocarbon bond between carbon atoms.
• Photographs 2.2 and 2.3 show the use
of members of the alkane homologous Functional A single covalent bond
series in their natural existence and for Group between carbon atoms, C C
cooking, respectively.

Photograph 2.2 The Photograph 2.3 General CnH2n+2 , n = 1,2,3...
Formula
thin waxy layer on fruits Butane gas, iCs 4aHn1a0 luksaende
is an alkane for cooking

H H HH HH Each carbon atom is bonded to four other atoms
HCH H HC CC HH HC CH by a single covalent bond of C C or C H.

H H HH HH

Structural formula of Model of
CH4 CH4 molecule

Example: Video50 B02-73a
First member, n = 1 Constructing ModelsBab10/2
http://kubupublication.com.my/Kimia/Tingkatan5/Video50.html

Molecular formula: C1 H2(1) + 2 = CH4 of Alkane Molecules
https://bit.ly/kpkt5v50
Name of member: Methane (Refer to Tables 2.4 and 2.5)

A ctivity 2C Constructing a Model of an Alkane Molecule PAK 21

Conduct this activity in groups. 2. Referring to the model built for the first
Materials: Model of carbon and hydrogen atoms ten members of straight chain alkane:

Procedure: (a) write the molecular formula.
1. Construct a molecular model for the first ten (b) draw the structural formula.
(c) name them according to the IUPAC
members of the straight chain alkane using nomenclature.
the provided model.
3. Present your work by using Table 2.6 as
Table 2.6 The first ten members of alkanes your reference.

Number of Name of Molecular formula Structural Bab 10/2 Nota33 B02-73b
carbon atom alkane CnH2n+2 formula http://kubupublication.com.my/Kimia/Tingkatan5/Nota33.pdf

1 Methane CH4 H

2 Ethane C2H6 HCH The First Ten
H Members of Alkanes

HH https://bit.ly/kpkt5n33

HC CH 73
HH

HHH

HC C CH
HHH

Theme 2 Organic Chemistry

Alkene

• Did you know that fruits produce ethene Unsaturated e presence of double covalent
Hydrocarbon bonds between carbon atoms.
grthiapese,anlC.keE2Hnthe4ehnnoeamtguoarlsao,lglCyo,2uHsc4aseuisrsiiaensgm. etmhebmer to
of

Functional Double bond between carbon
Group atoms, C C

General CnH2n , n = 2,3...
Formula

Photograph 2.4 Ripening bananas Example:
First member, n = 2
HH Molecular formula: C2H2(2) = C2H4
HC CH • Root name: Obtained from the longest carbon chain.

Structural formula Model of C2H4 molecule • Add the suffix “ene” to the root name because “ene”
of C2H4 is a member of the alkene homologous series.

Name of member: Ethene

A ctivity 2D
Copy and complete Table 2.7 for the first nine members of alkene.

Table 2.7 The first nine members of alkene

Number of Name Molecular Structural formula Bab 10/2 Nota34 B02-74
carbon atom formula
http://kubupublication.com.my/Kimia/Tingkatan5/Nota34.pdf

2 Ethene C2H4 HH
CC
HH The First Nine
Members of Alkene
3 Propene C3H6 HHH
HC C CH https://bit.ly/kpkt5n34

H

4 But-1-ene C4H8 H HHH
HC C CCH

HH

74

Carbon Compound Chapter 2

Alkyne Unsaturated e presence of triple covalent

• Photograph 2.5 shows ethyne gas, Hydrocarbon bonds between carbon atoms.
hECot2hHmy2onletoh, gCaot2uHiss2sieusrsaieemds.efmorbecruotftitnhge metal.
alkyne

Functional Triple bond between carbon
Group atoms, C C

General CnH2n-2 , n = 2,3...
Formula

Photograph 2.5 Ethyne gas that is used Example:
for metal cutting First member, n = 2
Molecular formula: C2H2(2)−2 = C2H2
HC CH • Root name: Obtained from the longest carbon chain.
Structural formula of C2H2 Model of C2H2 molecule
• Add the suffix “yne” to the root name because
“yne” is a member of the alkyne homologous series.

Name of member: Ethyne

A ctivity 2E
Copy and complete Table 2.8 for the first six members of alkyne.

Table 2.8 The first six members of alkyne

Number of Name Molecular Structural formula Bab 10/2 Nota35 B02-75
carbon atom formula
http://kubupublication.com.my/Kimia/Tingkatan5/Nota35.pdf

2 Ethyne C2H4 HC CH

3 Propyne C3H6 H The First Six
4 But-1-yne C4H6 HC CCH Members of Alkyne

H https://bit.ly/kpkt5n35

HH
HC CC CH

HH

75

Theme 2 Organic Chemistry

Alcohol Non Contains carbon, hydrogen
Hydrocarbon and oxygen atoms.
• Photograph 2.6 shows examples of various
items produced from members of alcohol
homologous series.

Functional Hydroxyl group, OH
Group

General CnH2n+1OH, n = 1,2,3...
Formula

Antiseptic Perfume
Alcohol
The hydroxyl group OH is
different from the hydroxide
ion OH‒ in alkali. There are no
hydroxide ions OH‒ in alcohol.

Solvent Fuel HHH
HCCC OH
Photograph 2.6 Examples of items that are
produced from alcohol

Example: HHH Model of C3H7OH molecule
Third member, n = 3 Structural formula of
Molecular formula: C3H2(3) + 1OH = C3H7OH
C3H7OH

• Naming of straight chain alcohol according to the IUPAC nomenclature:
(i) Determine the number of carbon atoms in the longest carbon chain containing the
hydroxyl group OH to derive the name of the alkane containing the same number of
carbon atoms as alcohol.
(ii) Replace the “e” ending from the alkane name with “ol”.
Example:
Corresponding alkane name: Propane

HHH Alcohol name: Propanol
H C1 C2 C3 H Hydroxyl position is at the first carbon
IUPAC name: Propan-1-ol
OH H H

Mind Structural formula A Structural formula B Discuss why structural
Challenge formula A is correctly
HH HH drawn while structural
HCC H HCC H formula B is incorrect.

H OH H OH

76

Carbon Compound Chapter 2

Carboxylic Acid Non Contains carbon, hydrogen
Hydrocarbon and oxygen atoms.
• Ant bites that cause pain contain
methanoic acid, HCOOH or formic
acid. Vinegar contains ethanoic acid,
CacHet3iCc OacOidH. , which is also known as
Do you know that ethanoic Functional Carboxyl group, COOH
Group
acid and methanoic acid are members of
carboxylic acids homologous series?

General CnH2n+1COOH, n = 0,1,2,3...
Formula

O
HC

OH

Photograph 2.7 Ant bites and vinegar Structural formula Model of HCOOH
HCOOH molecule
• Naming of carboxylic acid according to the
IUPAC nomenclature: Example:
(i) Determine the number of carbon atoms, First member, n = 0
and state the corresponding alkane name. Molecular formula: C0 H2(0) +1 COOH = HCOOH

(ii) Replace the “e” ending from the alkane name with “oic acid”.
Example:
(a) Molecular formula: HCOOH (b) Molecular formula: CH3COOH
The number of carbon atom is 1 The number of carbon atoms is 2

The corresponding alkane name is methane. The corresponding alkane name is ethane.

A The name for HCOOH is methanoic acid. T he name for CH3COOH is ethanoic acid.
ctivity 2F
1. Copy and complete Table 2.9 to show the molecular formula, structural formula and the
names for the first six straight chain members of alcohol and carboxylic acid.

Table 2.9 The first six members of alcohol and carboxylic acid

n Molecular formula Number of carbon atom Structural formula Name

2. Explain why the first value of n is 0 for the general Bab 10/2 Nota4 B02-77 Worksheet for the First Six
formula of the carboxylic acid homologous series. http://kubupublication.com.my/Kimia/Tingkatan5/Nota4.pdf
3. Explain why the carboxyl functional group COOH
always occur at the first carbon. Members of Alcohol and
Carboxylic Acid
https://bit.ly/kpkt5n4

77

Theme 2 Organic Chemistry

Describing the Physical Properties of Compounds in a Homologous Series

Physical Properties of Alkane, Alkene and Alkyne
• Members of the homologous series of alkane, alkene and alkyne consist of neutral molecules.
• Alkanes, alkenes and alkynes have physical properties of covalent compounds as shown
in Figure 2.6.

Physical Properties of Alkane, Alkene and Alkyne

Solubility Electrical Melting and Density
• Soluble in Conductivity Boiling Points • Less dense

organic solvent. • Cannot conduct • Low melting and than water.
• Insoluble in electricity in boiling points
all states. that increase
water. as the molecule
size increases.

A ctivity Figure 2.6 Physical properties of alkane, alkene and alkyne PAK 21

2G

You are required to conduct this activity in groups.
Table 2.10 shows the physical properties of the first seven members of alkane and Table 2.11
shows the physical properties of the first six members of alkene.

Table 2.10 Physical properties of the first seven Table 2.11 Physical properties of the first six
members of alkane members of alkene

Molecular Melting Boiling Physical Molecular Melting Boiling Physical
formula point/°C point/°C state at room formula point/°C point/°C state at room
temperature temperature
CH4 -182 -162 C2H4 -169 -104
C2H6 -183 -89 … C3H6 -185 -47 …
C3H8 -188 -42 … C4H8 -185 -6 …
C4H10 -138 -0.5 … C5H10 -165 30 …
C5H12 -130 36 … C6H12 -140 63 …
C6H14 -95 69 … C7H14 -119 93 …
C7H16 -91 98 … …
…

1. Complete Tables 2.10 and 2.11.
2. Based on the data in Tables 2.10 and 2.11, state and explain the three characteristics of the

homologous series shown by alkane and alkene.
Present your answer in a Gallery Walk activity.

• From Activity 2G, you are able to identify the changes in the physical properties for the first
seven members of alkanes and the first six members of alkenes.

• Therefore, it can be concluded that as the number of carbon atoms in each molecule increases,
the molecular size increases, the van der Waals force or the attraction between molecules also
becomes stronger. More heat energy is needed to overcome this force, and therefore the melting
point and boiling point also increase.
78

Carbon Compound Chapter 2

Physical Properties of Alcohol and Carboxylic Acid
• Alcohol and carboxylic acid are non hydrocarbon organic compounds containing carbon,

hydrogen and oxygen.
• The boiling points of alcohol and carboxylic acid are relatively higher than their

corresponding alkenes.
• Their solubility in water decreases as the molecule size increases.
• Table 2.12 shows the physical properties of alcohol and carboxylic acid.

Table 2.12 Physical properties of alcohol and carboxylic acid

Homologous series Alcohol Carboxylic acid
• Low boiling point that increases • Low boiling point that increases with
Boiling point with the increasing number of the increasing number of carbon
carbon atoms per molecule. atoms per molecule.
Physical state at • The first eleven members of • The first nine members of carboxylic
room temperature alcohol exist as liquids. acid exist as liquids.
• Methanol, ethanol and • Methanoic acid, ethanoic acid and
propanol are miscible in water propanoic acid are very soluble in water.
Solubility in water in all proportions. • As the molecular size increases, the
• As the molecular size increases, solubility decreases.
the solubility decreases.

2.2

1. Complete the following tree map with respective homologous series and general formula.
Organic Compounds

Hydrocarbon Non Hydrocarbon

Homologous Series

General Formula

2. Table 2.13 shows the molecular formula of organic compounds P, Q, R, S and T from different
homologous series.
Table 2.13

P Q R S T
C3H7COOH C4H8 C3H7OH C7H16 C5H8

(a) For all compounds in the table above:
(i) state their homologous series,
(ii) draw the structural formula,
(iii) write their IUPAC names.

(b) List all compounds that exist in the form of:
(i) gas at room temperature. (ii) liquid at room temperature.

(c) List all compounds that: (ii) do not dissolve in water.
(i) dissolve in water.

(d) Compare the boiling points of compounds Q and S. Explain your answer.

79

Theme 2 Organic Chemistry

2.3 CHEMICAL PROPERTIES AND INTERCONVERSION
OF COMPOUNDS BETWEEN HOMOLOGOUS SERIES

Chemical Properties of Alkane Standards

• Each homologous series has a functional group that is Pupils are able to:
different from other homologous series. The functional 2.3.1 describe the chemical properties
group determines the chemical properties of a
homologous series. of each homologous series
• Alkanes are saturated hydrocarbons that only have a single through activities.
2.3.2 understand ester through activity.

covalent bond C C and C H.
• Alkanes are unreactive because the strong C C and C H bonds can only be broken by a large
amount of energy.
• Even though alkanes do not react with most chemical substances, they undergo two types of
reactions:
I. Combustion II. Substitution

I. Combustion Reaction

• FAolkraenxeasmbpulren, accoommppleletetelycoinmebxucsetsisonoxoyfgmene,thOa2n, er,eCleHas4ining ecxacrebsosnoxdyiogxenid,eO, 2CoOc2cuarnsdaswfaotlelro,wHs:2O.
CH4(g) + 2O2(g) → CO2(g) + 2H2O(l)

• Alkanes undergo incomplete combustion when there is not enough or limited supply of
oionfxcysogomeontp),l,eOctea2r.cboIonmncbomumsotpniloeontxeiodcfeommgeabtshu, asCntiOeo,nCwHohfi4caohlckicasunpresosaissporfnoooldluouswc,esas:ncdarwbaotnerp, aHrt2Oicl.eAs,nCex(ainmtphlee form
of an

2CH4(g) + 3O2(g) → 2CO(g) + 4H2O(l)

CH4(g) + O2(g) → C(s) + 2H2O(l)

Balancing the equation for combustion:
• The combustion of alkanes release large Step 1: Balance C.
Step 2: Balance H.
amounts of heat. Therefore, it is very suitable Step 3: Balance O and you can use fractions.
to be used as fuel.
• The combustion of alkanes with more number
of carbon atoms, C will produce more soot.

• MDThueeethmtaoaniietnsgcfaolasm,mCpmHo4anibseinalitltsyoo,fpmnroaetdtuhuracaneledg,awCshHies4ncmaoenrgthcaaanunicseew, CfaiHsrte4es. decomposes in the absence of oxygen, O2.
• at landfills and peatlands.


80

Carbon Compound Chapter 2

Small hydrocarbon molecules such as natural gas
for vehicles (NGV) and petrol are denser than air.
Mind Therefore, at petrol stations, the use of mobile
Challenge phones or smoking while refuelling is prohibited
as shown in Figure 2.7. Explain the rationale for
this prohibition by relating to the physical and
chemical properties of these hydrocarbons.
Figure 2.7 Prohibition on smoking
and using mobile phones

II. Substitution Reaction

• Alkanes undergo substitution reaction with halogens such as chlorine, Cl2 and bromine, Br2
under sunlight or ultraviolet (UV) rays.

Substitution reaction occurs when each hydrogen atom, H in an alkane molecule is substituted
one by one with halogen atoms, until all the hydrogen atoms, H have been substituted.

• Sunlight or UV rays are needed to break the covalent bonds in the halogen molecules, such as
chlorine, Cl2 to produce chlorine atoms, Cl.

Example:
• Wforhmenedmdeutehtaonethgeassu,bCstHit4utrieoanctrseawcittihonc.hlorine gas, Cl2 under sunlight, various molecules are
• The following chemical equations show how the chlorine atoms, Cl from the chlorine
molecule, tCetl2rarcehplloarcoesm, estthagaenebymsotlaegceu,leth, Ce Chyl4dirsofgoernmaetdo.ms, H from the methane molecule,
CH4 until

Stage 1 Stage 2

H ϩUV H H ϩUV CI
H C CI H C CI
ϩH C H CI CI HCI ϩH C CI CI CI HCI

H UV H HCl(g) H UV H HCl(g)

MCeHth4(agn)e ϩ Cl2(g) ChlCoHro3mCel(tgh)anϩe ChlCoHro3mCel(tgh)anϩe Cl2(g) DichClHor2oCml2e(gth) aϩne

Stage 4 Stage 3

CI ϩUV CI CI ϩUV CI
CI C CI H C CI
ϩH C CI CI CI H CI ϩH C CI CI CI H CI

CI UVTetrachClCoCrlIo4(mg)ethϩaneHCl(g) H Cl2(g) UVTrichClHorCoCmlI3(egt)haϩne HCl(g)

TriCchHloCrlo3m(ge)thaϩne Cl2(g) DicChlHor2oCml2(egt)hanϩe

81

Theme 2 Organic Chemistry

A ctivity 2H PAK 21
Conduct this activity in groups.
1. Write the balance equation for the combustion of the following alkane:
(a) Ethane, C2H6 (b) Propane, C3H8 (c) Hexane, C6H14 (d) Octane, C8H18
2. Based on your knowledge on the reaction between alkane and halogen, discuss how ethane, C2H6
and bromine, Beqr2uraetaioctnwfoitrhetahcehpsrtaegseenocfetohfe sunlight: reaction that occurs.
(a) Write the substitution
(b) Name each of the compounds formed.

Share your answers in a Gallery Walk activity.

Chemical Properties of Alkene

• Alkenes are chemically more reactive than alkanes due to the existence of a double covalent bond
between two carbon atoms, C. Almost all chemical reactions in alkenes occur at the double bond.

• Chemical reactions of alkenes are as follows:
I. Combustion.
II. Addition.
III. Addition polymerisation.

I. Combustion Reaction

• Alkenes burn completely in excess oasxyfoglelno,wOs:2 to produce carbon dioxide, CO2 and water, H2O.
The combustion of ethene, C2H4 is

C2H4(g) + 3O2(g) → 2CO2(g) + 2H2O(l)

• pATahlkreteicncoleemss b(uiunnsdttiehorengfooofrimnalckooemfnseposloectta)en, ccpaorrmobdobunucsmetiaoonnfloaimxnideiewngsiatuhsf,fmiCcioOernetthsaootoxitysgcpoeonmi,spoOanr2oedusustpoapntlhdyewitroactoeforr,rremHsp2Oocan.rdbionng
• alkanes. This is because alkenes have a higher percentage of carbon by mass compared to alkanes.

II. Addition Reaction

• As alkenes are unsaturated hydrocarbons, they undergo addition reactions.
Addition reaction occurs when another atom is added to each carbon atom, C at the double
bond C C to form a single covalent bond C C .

HH ϩX Y HH
CC CC
YX
Unsaturated Saturated

82

Carbon Compound Chapter 2

• Five addition reactions that occur on alkenes:
1 Addition of hydrogen (Hydrogenation).
2 Addition of halogen (Halogenation).
3 Addition of halogen halide.
4 Addition of water (Hydration).
5 Oxidation with acidi ed potassium manganate(VII), KMnO4 solution.

1. Addition of Hydrogen (Hydrogenation) Bab 10/2 Video24 B02-83 Hydrogenation of Ethene
http://kubupublication.com.my/Kimia/Tingkatan5/Video24.html
• Alkenes react with hydrogen at a temperature of 180 °C
in the presence of nickel /platinum as a catalyst to https://bit.ly/kpkt5v24
produce the corresponding alkanes.
CnH2n + H2 1 8 N 0 i° C CnH2n+2
Alkene Alkane

Example:
Eprthodenuecegeatsh, aCn2eHg4arse,aCct2Hs w6.ith hydrogen gas, H2 in the presence of nickel as a catalyst at 180 °C to

HH Ni HH Catalytic hydrogenation is
H C C H+ H H 180 °C HC CH a method used to convert
vegetable oils to solid
Ethene Hydrogen Ni HH fats in the margarine
C2H4(g) + H2(g) 180 °C manufacturing industry.
Ethane
C2H6(g)

2. Addition of Halogen (Halogenation)

• Aebxrloakmmenpienlsee,rwweaahtceetrn,wBeittrhh2 eihsnaedleogcgaoesln,osCur2sHiusec4dhi.sabsucbhblolerdinteh,rCoul2ghanbdrobmroimneinwea, tBerr,2 at room conditions. For
Br2, the brown colour of

HH HH Mind Predict the products
H C C H + Br Br HC CH Challenge

Br Br of the reaction C2H4
between ethene,
Ethene Bromine 1,2-dibromoethane and chlorine,Cl2.

C2H4(g) + Br2(l) C2H4Br2(l)

83

Theme 2 Organic Chemistry

3. Addition of Hydrogen Halide

• Alkenes react with hydrogen halides, such as hydrogen chloride, HCl or hydrogen bromide, HBr
at room temperature to form haloalkane.
• For example, when dry hydrogen bromide gas, HBr is passed through ethene gas, C2H4,
bromoethane is produced.

HH HH
H C C H + H Br HC CH

Ethene Hydrogen Bromide H Br
C2H4(g) + HBr(g)
Bromoethane

C2H5Br(l)

4. Addition of Water (Hydration)

• Alkenes react with water (in the form of steam) at high temperature and pressure, in the presence
of phosphoric acid, H3PO4 as a catalyst to produce alcohol.

CnH2n + H2O H3PO4 CnH2n+1OH
300 °C, 60 atm
Hydration of alkenes
• For example, etthheetneemgpaesr, aCtu2Hre4 undergoes an addition reaction is a method of alcohol
with steam at of 300 °C, pressure of 60 atm and preparation in the alcohol
catalysed by phosphoric acid, H3PO4 to produce ethanol, C2H5OH. production industry.

HH OH H3PO4 HH
H C C H+ H 300 °C, 60 atm
HC CH
Ethene Steam
H OH
C2H4(g) + H2O(g)
Ethanol
C2H5OH(l)

5. Oxidation with Acidified Potassium Manganate(VII), KMnO4 Solution

• Alkenes react with acidified potassium manganate(VII), KthMe dnoOu4bsloelubtoinond.. KMnO4 solution.
• In this reaction, two hydroxyl groups OH are added to
• Alkenes decolourise the purple colour of acidified potassium manganate(VII),
For example:

HH KMnO4/H+ HH
H C C H + H OH + [O] KMnO4/H+
HC CH
Ethene + H2O(l) + [O]
C2H4(g) OH OH

Ethan-1,2-diol

C2H4(OH)2

84

Carbon Compound Chapter 2

III. Addition Polymerisation Reaction

• Small alkene molecules undergo addition reaction with Polymer: Addition
one another to form long chain molecules. polymerisation on
• Alkene molecules link together to form a long chain of page 147.
molecules called polymer, while the smaller alkene
molecules are the basic units called monomers.
• The reaction of alkene monomers to form polymers is called addition polymerisation.
Example:

pErthodenuec,eCp2oHly4tuhnendeer. goes addition polymerisation at 200 °C and pressure of 1200 atm to

• This reaction is simplified in Figure 2.8.

HH HH HH HH HH HH
..... C C + C C + C C ..... ~C C CC
C C~

HH HH HH HH HH HH

Monomer: Ethene Polymer: Polytene

Figure 2.8 Polymerisation of ethene, C2H4

• In general, the polymerisation equation is as follows:

HH HH Mind Compare and contrast
Challenge ethene and polythene
nC C CC with reference to their
structural formulae.
HH H Hn

n is any sizeable integer value.

Comparison Between Alkanes and Alkenes

Hydrocarbons containing only the carbon and hydrogen elements

Complete combustion produces carbon dioxide, CO2 and water, H2O

Alkane Same physical properties Alkene
Example: Hexane, C6H14 Number of carbon Example: Hexene, C6H12
Saturated hydrocabon atoms are the same Unsaturated hydrocarbon

Single covalent bond C C Double covalent bond C C

Substitution reaction Addition reaction

Percentage of carbon by mass is lower Percentage of carbon by mass is higher

Less sooty ames More sooty ames

85

Theme 2 Organic Chemistry

2A Comparing Alkane and Alkene

A. Sootiness of Flame PAK 21 Learning Science
Through Inquiry

Aim: To compare hexane, C6H14 and hexene, C6H12 for sootiness of flames during combustion.
Problem statement: Do alkanes and alkenes burn with the same quantity of soot?

Hypothesis: Hexene, C6H12 burns with a more sooty flame compared to hexane, C6H14.

Variable: : SHoeoxtainnees, sCo6Hf f1l4amaneds.hexene, C6H12.
(a) Manipulated variable :
(b) Responding variable
(c) Constant variable : Volume of hexane, C6H14 and hexene, C6H12.
Materials: Hexane, C6H14, hexene, C6H12, wooden splinter, matches and filter paper.
Apparatus: Evaporating dish and measuring cylinder.

Procedure: CAUTION
1. fPWUiolsthueeerranp2laihcgpemhextra3enaodbefw,ohCvoeeox6Hadthne14enes,fstClapar6mlHtinse1tt4eaoirsnbtstuohoroinagwn,nnpietlveianachpeFeoaixrgaapuntirieeenc, ge2C.do96Hif.sh14.. Use safety goggles when
2. conducting this experiment.
3.
RtRoeerpceoepradltascttheeephsoexb1astenorev3,aCuti6soHinn1g4o. hf tehxeensoe,oCti6nHes12s of the flame and
4.

5.
the quantity of soot formed on the filter paper.
Filter paper

AB.i m R: eTuacsotinicogonmbwrpoiamtrheinBhereoxwmaantieen,re,CBW6Hr2a.1 t4 e arn, dBrh2exene, C6H12 Hexane, C6H14 Hexene, C6H12
doHfoebexsreonnmoe,tinCdee6Hcwo1a2lotdeuerr,ciBoselro2tuhwrehisbielresothwhenexabnroe,wCn6Hco1l4our
Hypothesis: Evaporating dish

Figure 2.9

colour of bromine water, Br2.

Variable: : CHVooelxlouaumnreec, ohCfa6nHhge1xe4 aaonnfedb, rhCoe6mxHei1nn4 eea,nwCda6tHheer1x2,.eBnre2.,
(a) Manipulated variable :
(b) Responding variable : C6H12.
(c) Constant variable

Materials: Hexane, C6H14, hexene, C6H12 and bromine water, Br2 in 1,1,1-trichloroethane, CH3CCl3.
Apparatus: Test tube, measuring cylinder and dropper.

Procedure: 1B,r1o,1m-tinriechwloatreore,tBhra2nien,
1. 1PaAs,od1su,dh1r-o22twr-cinc3mhid3lnoroorFfopihgesuteohxrfaeanbn2ree.o,1, mC0C.H6iHn3eC14wCinal3ttoetora, hBteerxs2taintnueb, eC. 6H14 CH3CCl3
2.
Hexane, C6H14
Figure 2.10
3. Shake the mixture.
4. Record all observations.
5. Repeat steps 1 to 4 using hexene, C6H12 to
replace hexane, C6H14.

86

Carbon Compound Chapter 2

C. Reaction with Acidified Potassium Manganate(VII), aKcMidinfiOed4 Solution
mToancogamnpaater(eVhIeIx),aKneM, Cn6OH41s4oalnudtiohnex. ene, C6H12 using potassium
Aim:


Hypothesis: KHmMeaxnnegnOaen4,asCtoe6l(HuVt1iI2oIdn),ewKcohMliolneuOrhie4sexssoanltuhete,ioCpn6uH.rp14ledcooelsonuortodfeaccoidloifuieridsepaoctaidssifiiuemd pmoatansgsaiunmate (VII),



Variable: CHoelxoaunrec,hCa6nHge14oafnadcihdeifxieednep,oCta6sHsi1u2.m manganate(VII),
(a) Manipulated variable : Volume of hexane, C6H14 and hexene, C6H12.
(b) Responding variable : KMnO4 solution.
(c) Constant variable :

Materials: Hexane, C6H14, hexene, C6H12 and acidified potassium manganate(VII), KMnO4 solution.
Apparatus: Test tube, measuring cylinder and dropper.

Procedure: tube.
1. PAodudr22–cm3 d3 orofphsexoafnaec,idCif6iHed14 into a test manganate(VII),
2. C6H14, as potassium Figure 2.11. KMnO4 Acidified
solution to hexane, shown in potassium
3. Shake the mixture. manganate(VII)
4. Record all the observations. solution, KMnO4
5. Repeat steps 1 to 4 using hexene, C6H12
to replace hexane, C6H14. Hexane, C6H14
Figure 2.11
Observation:
Construct a table to record your observations.

Discussion:
1. ( ((bac))) CaBSntaaadsltceeuhdtlehaoxteneenryteehol,eauCtpri6oeHonrbc1ss2eh.enirptvaagbteeiotownfesc,eancrobtmohnepbparyeermctehanestssapogeoertoimnf ecosalsercbouoflnfelaibnmyhemsexaoasfnshepe,exCra6mnHeo1,4lCeac6nHudl1eh4 ie nxehneex,aCn6eH, 12.
(a) SCu6Hgg1e4satntwdoherexaegneen,tCs 6tHha1t2,caanndbethuesesodototindeisstsinogfutihseh flames.
Explain your answer. between


2. hexane, C6H14 and hexene, C6H12.

(b) Explain the difference in reactivity of hexane, C6H14 and hexene, C6H12 in terms of chemical
bonds in their molecules.
3. What is the operational definition of unsaturated hydrocarbons in this experiment?

Prepare a complete report after carrying out this experiment.

• The combustion of alkenes produces more soot compared to alkanes. This is because the
percentage of carbon by mass per molecule is higher in alkenes than alkanes.

Example:

Corresponding hydrocarbon Propane, C3H8 Propene, C3H6
% C = 3 ( 1 32()1+2)6 ( 1 )  100%
Percentage of carbon by mass %C = 3 ( 1 32()1+2)8 ( 1 )  100% = 85.71%
per molecule = 81.82%

87

Theme 2 Organic Chemistry

• cTParhroebposeonnoebt,yfComr3Hmas6esbdpuiersrncmsarwobiloethncu.aTleshoienogtpirereroapftleearnmtehe, eCcno3Hmum6piabsreheridgohtfoecraprtrbhooapnnanapetro,omCpa3sHnpe8e,brCem3cHaoul8e.sceutlhee, percentage of
• the higher the
percentage of carbon by mass per molecule and the more soot is produced by the flame.
• Alkenes react wdoithnobtroshmoiwneawnyatcehr,aBnrg2easnwdiathcitdhifeiseedtpwootarsesaiguemntms.anganate(VII), KMnO4 solution,
while alkanes
• Alkenes are more reactive than alkanes due to the presence of double bonds in alkene molecules.
Addition reaction occurs in alkenes but does not occur in alkanes.

A ctivity 2I PAK 21
1. Copy and complete the tree map by writing the chemical equation for each addition reaction
that occurs on ethene, C2H4.

Ethene, C2H4

Addition of Addition of Addition of Addition of Addition of Addition
Hydrogen, Halogen, Br2 Hydrogen W30a0te°Cr, ,H620Oa,tHm3PO4, Hydroxyl Group, Polymerisation
H2, Ni, 180 °C Halide, HBr Acidi ed KMnO4

2. H(ae)x Satnaet,eCth6He 1d4iaffnedrehnecxeeinneo, Cbs6eHrv12aatiroencsowlohuernlebssoltihquliiqdusi.ds are burnt in excess oxygen.
Explain why the differences occur.

(b) Other than combustion, describe a chemical test that can be used to distinguish these
two liquids.

Preparation of Alcohol

• ETtwhoanmoel,thCo2Hds5OofHetihsatnhoelmporespt aimraptioornta: nt alcohol and has many uses.
•
(a) Fermentation of glucose or starch with the presence of yeast.
(b) Hydration of ethene, C2H4 with the presence of a catalyst.

Fermentation of Glucose

• Fermentation is the process in which yeast acts on carbohydrates (sugar or starch) to produce
eYtehaasnt oclo, nCt2aHin5sOtHheaenndzycmareboznymdiaosxeitdhea,tCaOct2s in tahceaatbalsyesntc, ewohficohxybgreeank, sOd2o. wn
• as sugar or starch into
glucose. Fermentation of glucose will produce ethanol, C2H5OH and carbon dioxide, CO2.

88

Carbon Compound Chapter 2

Chemical equation for fermentation:
C6H12O6(aq) Z y m a s e e n z y m e 2C2H5OH(l) + 2CO2(g)
Glucose Ethanol Carbon dioxide

• The ethanol, C2H5OH produced is purified by fractional distillation.

Hydration of Ethene

• Ephthoesnpeh,oCri2cHa4crieda,cHts3PwOit4hassteaacmata(Hly2sOt ) at 300 °C and pressure of 60 atm, with the presence of
CE2tHhe4(nge) + HSt2eOa(mg) 3 0 0 H ° C 3 P, 6O 0 4 a t m C 2EHt5hOanHo(ll)

Laboratory Activity 2B Preparation of Ethanol, C2H5OH Through Fermentation
of Glucose

Aim: To prepare ethanol, C2H5OH through fermentation of glucose. PAK 21 Learning Science
Through Inquiry

Materials: Glucose, C6H12O6, yeast, limewater, distilled water and filter paper.
Apparatus: Conical flask, beaker, measuring cylinder, round-bottom flask, delivery tube, stopper,
test tube, thermometer, fractionating column, Liebig condenser, retort stand,
wire gauze, Bunsen burner, tripod stand, rubber tubing, filter funnel and glass rod.

Fractionating column Thermometer
Water out
Liebig
condenser

Filtered
fermentation
product
Water

Water in

Glucose solution Limewater Heat Ethanol,
+ yeast C2H5OH

(a) Set up of apparatus for fermentation (b) Set up of apparatus for distillation

Figure 2.12 Preparation of ethanol through glucose fermentation

Procedure: 200 cm3
1. PAudtd2100ggooffgyleuacsotsien,tCo 6tHhe12cOo6niincatol flask and of distilled water into a conical flask.
2. stir with a glass rod until the mixture is even.
3. Close the conical flask with a stopper connected to the delivery tube.

89

Theme 2 Organic Chemistry

4. Insert the end of the delivery tube into the test tube as shown in Figure 2.12.
Make sure the end of the delivery tube is dipped into the limewater.
5. Place the apparatus at room temperature (30 °C) for three days.
6. After three days, filter the mixture from the conical flask.
7. The filtrate is poured into a round-bottom flask. The apparatus for distillation is set up as

shown in Figure 2.12.
8. Heat the filtrate in the water bath and collect the distillate at 78 °C.
9. Record the colour and smell of the distillate.

Observation:
Construct a table to record your observations.

Discussion:
1. WWhhyatmisutshtethfuenecntdioonfotfhyeedaesltivinertyhteufbeermbeenimtamtioenrsoedf gilnucliomsee,wCa6tHer1?2O6?
2. Name gparos dreulcetasceodlleincttehdeinferfrmacetniotantaiol ndiostfiglllautcioonsea,tC768H°1C2O. 6.
3. Name the
4. the
5. WFEexrrpmiltaeeintnhtweathciohyneemtthoiacpnarlooeld,qCuuca2Hetieo5OtnhHafonfrortlo,hmCe 2ftHehre5mOfieHlntrtcaaatteniocanalsnoofbbgeeluscecaporasrreiae, tdCedo6Huat1t2uO7s86i.n°Cg .fruits. Explain why.
6.
7.

Results: CC22HH55OOHH can cboelopurerpleasrseadntdhrvooulagthilethlieqfueirdmaetnrtoaotimonteomf gpleurcaotuser,eC. 6H12O6.
1. Ethanol, is a
2. Ethanol,

Prepare a complete report after carrying out this laboratory activity.

Chemical Properties of Alcohol

• All alcohols have the same chemical properties due to the presence of hydroxyl group, OH as a
functional group. The important chemical reactions involving alcohols are:
I. Combustion II. Oxidation III. Dehydration

Combustion of Alcohol

• Alcohol burns in excess oxygen, wOi2tthoapbrloudeufclaemcaerbwoitnhdouiotxsiodoet,.CO2 and water, H2O.
• Alcohol is flammable and burns
For example:

C2H5OH(l) + 3O2(g) 2CO2(g) + 3H2O(l) • Alkanes, alkenes and alcohols
Ethanol Oxygen Carbon dioxide Water burn completely in oxygen,
producing carbon dioxide gas
• The combustion of ethanol, C2H5OH releases large and water.
quantities of heat.
• Ethanol, C2H5OH can be used as fuel for rockets. • Perform the same steps
as alkanes and alkenes to
balance the equation for the
combustion of alcohol.

90

Carbon Compound Chapter 2

Oxidation of Alcohol Redox:
• Alcohol can be oxidised to form carboxylic acids, Redox in terms of
a homologous series with functional group COOH transfer of oxygen or
in the presence of a suitable oxidising agent. hydrogen on page 4.

CnH2n+1OH + 2[O] → CmH2m+1COOH + H2O
n = 1,2,3… m = 0,1,2,3….
Alcohol Carboxylic acid

• Common oxidising agents include acidified potassium manganate(VII), KMnO4 solution and
acidified potassium dichromate(VI), K2Cr2O7 solution.
Example:
(a) Oxidation of ethanol, C2H5OH by acidified potassium manganate(VII), KMnO4 solution.

HH HO

H C C H ϩ 2[O] H C C OH ϩ H O H

H OH H

CH3CH2OH + 2[O] → CH3COOH + H2O

Chemical equation:

C2H5OH(l) + 2[O] CH3COOH(aq) + H2O(l)
Ethanol Ethanoic acid

tTghrhieseernpeuwarchptieloennci.toTrloheuaecrotsorafwnaigctheidceioftihleoadunrpoolo.tfIaanscstiihduiimsfiremedaapcntoigtoaansn,saieuttehm(aVndIoiIcl)h,isrKoaMmlsonatOoex(4VisdoIi)sl,ueKdti2oiCnnrto2iOsed7thescoaonlulootiiucornaiscteiuddr.nins
(b) Oxidation of propanol, C3H7OH.
C3H7OH(l) + 2[O] C2H5COOH(aq) + H2O(l)
Propanol Propanoic acid

Dehydration of Alcohol

• Dehydration of alcohol involves the removal of a water molecule from each alcohol molecule to
produce a corresponding alkene.

Cnn=H12n,+21,O3.H.. porcelain chips n =Cn2H,32,n4... ϩ H2O
∆

• Water molecules are removed from the alcohol Mind Methanol cannot
when alcohol vapour is flowed over a strongly Challenge undergo dehydration
heated catalyst, such as porcelain chips, reaction. Explain why.
aluminum oxide, alumina or concentrated sulphuric acid.

91

Theme 2 Organic Chemistry

Example: ethanol, C2H5OH.
(a) Dehydration of
H H HH
porcelain chips
HCC H H C C H ϩ H2O
∆

H OH e hydroxyl group, together with the hydrogen atom,
are removed from the adjacent carbon atoms to form water, H2O.
Chemical equation:

C2H5OH(l) porcelain chips C2H4(g) ϩ H2O(l)
Ethanol ∆ Ethene Water

(b) Dehydration of propanol, C3H7OH.

C3H7OH(l) porcelain chips C3H6(g) ϩ H2O(l)
Propanol ∆ Propene Water

• Alkene, produced from the dehydration of alcohol, has the following characteristics:
(i) burns with yellow sooty flame,
(ii) decolourises the pburropwlenccoololouurrooffpbortoamssiiunme wmaatenrg,aBnra2tteo(VcoIIl)o,uKrMlesnsO, 4
(iii) decolourises the solution to colourless.

Laboratory Activity 2C Chemical Properties of Ethanol

Aim: To study the chemical properties of ethanol, C2H5OH. PAK 21 Learning Science
Through Inquiry

Materials: asEoctihldua,tniHoon2l,S,COpo24H,tab5sOlusiHeuml,iptmomruacsnelpgaaainpneacrthe, i(bpVrsoI,Img)l,ianKsesMwwnaoOtoe4lr,s,poBolrut2at.isosniu,mcodniccehnrtormateadte(sVulIp)h, Kur2iCcr2O7



Apparatus: Test tube, boiling tube, boiling tube stopper with delivery tube, retort stand,
test tube holder, Bunsen burner, measuring cylinder, dropper and beaker.

A. Oxidation of Ethanol, C2H5OH CAUTION

Boiling tube Test tube Concentrated
Cold water sulphuric acid is
Acidified potassium Beaker corrosive. Handle
dsoicluhtrioomn aatned(VeIth),aKn2oCl,r2O7 Distillate with care.

C2H5OH Heat Figure 2.13

Procedure: into tube.
1. PAGodeundrt1l5y0chdmerao3tpotshf opefosoctaolsunstciiuoemnnt.rdaitcehdrosumlpahteu(rVicI)a,cKid2C, Hr22OSO7 s4o. lution a boiling
2.
3. CAodndn3eccmt t3h oefdeetlhivaenroyl,tuCb2eHt5oOtHhedbrooiplibnyg drop into the boiling tube.
tube as shown in Figure 2.13.
4. gentle flame until the mixture boils. Heat the mixture with a
5.

92

Carbon Compound Chapter 2

6. Collect the distillate in a test tube and test it with the blue litmus paper.
Repeat steps 1 to 6 by replacing potassium dichromate(VI), K2Cr2O7 solution with potassium
7. manganate(VII), KMnO4 solution.

Observation:

Test on Distillate Observation
Colour change of potassium dichromate(VI), K2Cr2O7 solution
Colour change of potassium manganate(VII), KMnO4 solution
Colour of distillate

Smell of distillate

Effect on blue litmus paper

Discussion: the oxidation reaction ethanol, C2H5OH?
1. What is the product formed by in this experiment. of
2. Name the oxidising agent used
3. Write the chemical equation of the reaction that occurs.
4. What is the property of the product of alcohol oxidation?

Conclusion: Glass wool soaked in ethanol, C2H5OH
Tprhoedouxciedsaetitohnanoofiectahcaindo, lC, HC23HCO5OOHH. Porcelain chips

B. Dehydration of Ethanol, C2H5OH
Procedure:
1. Place the glass wool in a boiling tube. Heat Gas

2. Pour 2 cm3 of ethanol, Cgl2aHss5OwHooiln. to the
boiling tube to wet the
3. Place the porcelain chips in the middle
of the boiling tube as shown in Figure 2.14.
4. Heat the porcelain chips with a strong flame. Water

Heat the glass wool with a gentle flame to vaporise Figure 2.14
the ethanol, tCes2tHt5uObHes and the vapour is flowed through the heated porcelain chips.
5. Collect two of the gas released, as shown in Figure 2.14.
(i) Add a few drops of bromine pwoattaesrs,iBumr2 into the first test tube and shake.
6. (ii) Add a few drops of acidified manganate(VII ), KMnO4 solution into the second
test tube and shake.

Observation: Observation
Reagent

Bromine water, Br2
Acidified potassium manganate(VII ), KMnO4 solution

Discussion: C2H5OH undergoes dehydration.
1. Name the gas released when ethanol,
2. State the function of porcelain chips.
3. Write the chemical equation for the dehydration of alcohol, C2H5OH.

Conclusion:
Dehydration of ethanol, C2H5OH produces ethene, C2H4.

Prepare a complete report after carrying out this laboratory activity.

93

Theme 2 Organic Chemistry

Chemical Properties of other Members of the Alcohol Homologous Series

• All members of the alcohol homologous series have the functional group hydroxyl OH, which
is similar to ethanol, Cof2Hth5eOhHom. ologous
• Thus, other members series also undergo combustion, oxidation and dehydration.

A ctivity 2J
Write the complete equation for each of the following alcohol reaction.
1. Complete combustion in excess oxygen:
(a) Methanol. (b) Propanol.

2. Oxidation by acidified potassium manganate(VII), KMnO4 oxidising agent:
(a) Butanol. (b) Pentanol.

3. Dehydration by porcelain chips as the catalyst:
(a) Butanol. (b) Pentanol.

Chemical Properties of Carboxylic Acids Carbon Compound:
Oxidation of alcohol
• Carboxylic acids can be produced from the on page 91.
oxidation of alcohol. • Reflux method is to ensure that
• Eesutthhcahannooali,scC2aaHccii5ddO,ifHieCdiHs 3oCpxoOidtaOissHseidumbisy produced when ethanol reacts completely with the
oxidising agents, oxidising agent.
drKeiMcflhunrxOomm4 eatthes(ooVdluIa)t,siosnKho2Cwrno2Orin7 manganate(VII), • A Liebig condenser that is fitted
acidified potassium upright into a round-bottom flask will
solution through the condense ethanol vapour to liquid
Figure 2.15. ethanol. Liquid ethanol flows back
into the round-bottom flask to react
HH HO completely with the oxidising agent.

H C C H ϩ 2[O] H C C OH ϩ H O H

H OH H

Water out

• The chemical properties of carboxylic acids are
studied through the chemical reactions of ethanoic
Water Liebig acid, CchHe3mCiOcaOl Hp. roperties
in condenser • The of carboxylic acids are

+Etohxaindoisl,inCg2Hag5OenHt • determined by the carboxyl, COOH functional group.
Two important chemical reactions of carboxylic acids:
(i) Reaction as an acid.
Water (ii) Reaction with alcohol.

Heat Form 4 Chemistry:
Figure 2.15 Ethanol oxidation reaction Chemical properties of acids

by oxidising agent through reflux

94

Carbon Compound Chapter 2

I. Chemical Reactions of Ethanoic Acid, CH3COOH

(a) Carboxylic acid + Base → Carboxylate salt + Water and
For example, the reaction b(CetHw3eCeOn Oet)h2Canuoaincdawciadt,erC, HH32COO. OH copper(II) oxide, CuO
produces copper ethanoate,

2CH3COOH(aq) + CuO(s) → (CH3COO)2Cu(aq) + H2O(l)

(b) Carboxylic acid + Metal carbonate → Carboxylate salt + Water + Carbon dioxide
For example, the reaction between ethanoic acid, dCiHox3CidOe,OCHO2ananddsowdaituemr, carbonate, Na2CO3
produces sodium ethanoate, CH3COONa, carbon H2O.

2CH3COOH(aq) + Na2CO3(s) → 2CH3COONa(aq) + H2O(l) + CO2(g)

(c) Carboxylic acid + Metal → Carboxylate salt + Hydrogen magnesium Mg
For example, the reaction between ethanoic acid, ChyHd3oCgOenO,HH2a. nd metal,
produces magnesium ethanoate, (CH3COO)2Mg and
2CH3COOH(aq) + Mg(s) → (CH3COO)2Mg(aq) + H2(g)

• Ethanoic acid is a weak acid that partially • Constructing the formula of
ionises in water, producing low concentration copper(II) ethanoate:
of hydrogen ions.
CH3C– OO– Cu2+
CH3COOH(aq) CH3COO–(aq) + H+(aq) 2+ : Charge of the ion

Ethanoic acid Ethanoate ion Hydrogen ion 2 1 : Cross-change the

(CH3COO)2Cu coe cient of the charge

II. Reaction with Alcohol

• Carboxylic acid reacts with alcohol to produce ester and water.

Carboxylic acid + Alcohol H2SO4 Ester + Water

CmH2m+1COOH CnH2n+1OH C o n c e n t r a t e d CmH2m+1COOCnH2n+1 H2O

• This reaction is called esterification, with the presence of concentrated sulphuric acid, H2SO4
as a catalyst.
Example:
Woisffhcooernnmcaeendm.trixatteudresuolfpghluacriicalaectihda, nHo2iScOa4c,iids,hCeaHte3Cd,OaOn Hestaenrdcaeltlehdaneothl,yCl e2Hth5aOnHoa,twe,iCthHa3CfeOwOdCro2Hps5

H H O H H H H2SO4 H H O H H H ϩH O H
C C C Concentrated C CO C C
C OH ϩ H O

H HH H HH

CH3COOH ϩ C2H5OH CH3COOC2H5 ϩ H2O

Ethanoic acid Ethanol Ethyl ethanoate Water

95

Theme 2 Organic Chemistry

• CwEtoahtnyeclre.enEthttrahanytoel daetteshu,aClnpHohau3tCreiO,cCOaHcCi3d2CH, OH5 Oi2sSCOa 2c4Hoisl5oafulocralaettssas,lyfliosqtruminidintthgheaaetlshatayesreirtfhiocenasttwihoeneestruefrraufcaittciyoensom.f ethlleawndatienrs.oluble in
•

Carbon Compound: • Water removal occurs at the carboxyl functional
Ester on page 97. group, COOH in carboxylic acid and hydroxyl,

OH in alcohol.
• Water molecule (H O H) is formed from the
OH that is removed from carboxylic acid and

the H that is removed from alcohol.

Chemical Properties of Other Homologous Series of Carboxylic Acids

• All members of the carboxylic acid homologous series have the same functional group as ethanoic
aTchidus, ,CoHth3eCrOcaOrbHoxwyhliicchaciisd scaarlsboosxhyol,w COOH.
• similar chemical properties with ethanoic acid, CH3COOH.

Laboratory Activity 2D Chemical Properties of Ethanoic Acid, CH3COOH

Aim: To study the chemical properties of ethanoic acid, CH3COOH. PAK 21 Learning Science
Through Inquiry

Problem statement: Can ethanoic acid, CH3COOH react with metal, metal oxide and
metal carbonate?

Materials: 1 mol dm−3 of ethanoic acid, oCxHid3Ce OpoOwHde, rm, CagunOesaiunmd lrimibebwonat,eMr.g, sodium carbonate
powder, Na2CO3, copper(II)

Apparatus: Test tube rack, stopper with delivery tube, Bunsen burner, test tube holder,
boiling tube, wooden splinter and glass rod.

Procedure: Using the apparatus and materials provided, plan an experiment to investigate the
reaction of ethanoic acid, CH3COOH with metal, metal carbonate and metal oxide.
Results: Record all observations in one table. Form 4 Chemistry:
Chemical properties
Discussion: of acids
1. Nr(WNaeaa)ar mmci ttMesee wtttahhhgieeetnhrsgeeassaaoilstucedstmsiipuor,rmneoMledecagquas ucreeabddtoiwonwnhahtseeenb,n(eNebett)wath h2aeCSanenoOnodoi3eiciucathanmacadcindicmdoa,,irCacCbgHoaHncn3ei3CadsCtiOueOa,OmnONdH,H:aM2CrgeO.a3ct s Copper(II) oxide, CuO
with:
2. (c)

3. (b) Sodium carbonate, Na2CO3 (c) Copper(II) oxide, CuO
(a) Magnesium, Mg

Conclusion: State the conclusion of the experiment you have conducted.

Prepare a complete report after carrying out this laboratory activity.

96

Carbon Compound Chapter 2

Ester

• Based on Figure 2.16, what do you Non Contains carbon, hydrogen
understand about ester? Hydrocarbon and oxygen atoms.

Madam, I ate a The strawberry flavour is Functional Carboxylate, O
strawberry flavoured not real strawberries. It is Group CO
ice cream. On the ice ethyl hexanoate, a member
cream packaging, it of the ester homologous
mentioned “Strawberry series, which can be prepared
flavour”. Is the through chemical reaction.
“Strawberry flavour”
from real strawberries? General Cmm=H02m,1+1,2C,O3..O.. CnnH=21n+,21 ,3...
Formula

• Ester is produced when carboxylic acid reacts with alcohol, as
previously studied in chemical properties of alcohol.

Carboxylic acid + Alcohol → Ester + Water

Figure 2.16 Understanding Ester

• The general formula of ester can be derived by combining parts of the alcohol molecular formula
and parts of the carboxylic acid molecular formula, with the removal of one water molecule.

Carboxylic acid + Alcohol → Ester + Water
CmH2m+1COOH CnH2n+1OH CmH2m+1COOCnH2n+1 H2O
m = 0,1,2,3.... n = 1,2,3...

• The general formula for ester can also be written as:

O R is CCmnHH22mn++11 from carboxylic acid
R C O R’ R’ is from alcohol

H H H OH H HH HO HH H H H OH H HH O H

H C C CH CC OC CC CC HO C C H H C C CH CC OC CC HC O C H

H H H H H HH H HH H H H H H HH H
Ethyl butanoate
Methyl butanoate

The fragrant smell
of flowers and
fruits are mostly
due to esters.

Photograph 2.8 Examples of the structural
formulae for esters found in fruits

97

Theme 2 Organic Chemistry

Naming of Ester
• The naming of esters comes from parts of alcohol and parts of carboxylic acid.

O

R C O R’

Part two: Part one:
Derived from carboxylic acid, Derived from alcohol,
the name ends with “oate”. the name ends with “yl”.

First part From the alcohol where “ol” is replaced with “yl”.

Second part From carboxylic acid where “oic acid” is replaced with “oate”.

Example:

Naming of the first part Naming of the second part Name of ester
Methanol ⇒ Methyl Methanoic acid ⇒ Methanoate Methyl methanoate
Ethanol ⇒ Ethyl Ethanoic acid ⇒ Ethanoate Ethyl ethanoate
Propanol ⇒ Propyl Propanoic acid ⇒ Propanoate Propyl propanoate

• Table 2.14 shows the steps to determine the name of esters and written equation for
esterification reaction.

Example 1:

Table 2.14 The steps to determine the name of ethyl methanoate ester and the
balanced equation for esterification reaction

Molecular formula HCOOC2H5

O HH

Structural HCO CC H .....
formula
HH • Eliminate hydroxyl group
Name of ester OH from carboxylic
Ethyl Methanoate
Ester produced From ethanol From methanoic acid acid , HCOOH.
from • Remove H atom from
HCOOH CE2tHha5OnoHl
Esterification Methanoic acid the hydroxyl group of
equation • aClocomhboiln, eCt2hHe5OtwHo.
HCOOH + C2H5OH → HCOOC2H5 + H2O
remaining parts by
forming an ester link
COO .

Example 2:
eTthheanesotaetrei,fiCcaHti3oCnOrOeaCct2Hio5nwbietthwteheenpertehsaennoceicoafccido,nCceHn3tCraOteOdHsualpnhduertihcaancoidl,,CH2H2S5OO4Hasfaorcmatsaleytshty. l

HO HH H2SO4 HO HH
Concentrated
H C C OH ϩ H O C C H HC CO C CHϩHO H

H HH H HH

CH3COOH ϩ C2H5OH CH3COOC2H5 ϩ H2O
Ethanoic acid Ethyl ethanoate
Ethanol Water

98

A ctivity 2K Carbon Compound Chapter 2

Write the molecular and structural formulae of alcohol and carboxylic acid components for
the following esters. Next, draw the structural formula of each of these esters.
(i) Methyl methanoate (ii) Ethyl propanoate (iii) Propyl ethanoate

Physical Properties of Esters

• Figure 2.17 shows a bubble map of physical properties of ester.

Neutral compounds with Possess low density,
sweet and fruity smell. less dense than water.

Covalent compounds that Physical Properties of Esters Simple esters are
do not dissolve in water. colourless liquids at
room temperature.

Simple esters are unstable and can
easily vaporise at room temperature.

Figure 2.17 Physical properties of ester

Laboratory Activity 2E Reaction of Ethanoic Acid with Ethanol

Aim: To study the reaction of ethanoic acid, CH3COOH PAK 21 Learning Science
with ethanol, C2H5OH. Through Inquiry

Materials: CG2lHac5iOalHetahnadnociocnacceindt, rCatHed3CsOulOphHu,raicbsaocliudt,eHe2tShOan4.ol, CAUTION

• Concentrated acid is
Apparatus: Beaker, Bunsen burner, test tube holder, corrosive.
boiling tube, dropper, glass rod and
measuring cylinder. • Do not overheat the
mixture as ethanol is
Procedure: highly flammable.

1. Add 4f2aivccdemmrod33prooopffpegarsblaoasncfoidclauolstnehetcaheektanehntartohnaitecoelbad,coCsiidu2liH,lnpC5ghOHutHur3CbicteOoaaOctshidHseh, gHoinlwa2ScaniObail4noeiinFltihnitgoagunttrhoueiebc2me.a1.ci8xid.tu, CreH3COOHC. oncentrated
2. Add
3. Add
with
4. Heat the mixture gently with a small flame to bring it to sulphuric acid,
a boil for two to three minutes. H2SO4

5. Pour the content of the boiling tube into a beaker half filled with water.
6. Record the smell, colour and solubility of the product.
Observation: +Etehtahnaonlo, iCc2aHc5iOd,H
Heat CH3COOH
Test Observation
Colour
Figure 2.18
Smell

Solubility

99

Theme 2 Organic Chemistry

Discussion: CH3COOH and ethanol, C2H5OH.
1. Name the reaction that occurs between glacial ethanoic acid,
2. Name the product formed from the reaction.
3. Compare the density of the product formed with water.
What itshteheeqfuuantciotinonfoorftchoenrceeancttiroantebdestuwlpeehnureitchaanciodi,cHac2SidO, 4C?H3COOH
4. Write and ethanol, C2H5OH.
5.

Conclusion:
Ethanoic acid, CH3COOH reacts with ethanol, C2H5OH to produce ester and water.

Prepare a complete report after carrying out this laboratory activity.

2.3

1. Table 2.15 shows carbon compounds and their respective molecular formulae.
Table 2.15

Compound P Q R T

Molecular formula C3H8 C3H6 C2H5OH CH3COOH

(a) (i) Compare and contrast the sootiness of flames of compound P and compound Q
when burnt in excess oxygen. Explain your answer.

[Relative atomic mass: C = 12, H = 1].
(ii) Table 2.16 shows the result of an experiment where compound P and compound Q

were separately shaken in bromine water in test tubes.

Table 2.16

Compound Observation

P The brown colour of bromine water does not change.

Q The brown colour of bromine water decolourises.

Based on Table 2.16, explain the differences in these observations.

(b) 2.3 g of compound R burns completely in excess oxygen to produce carbon dioxide gas
and water. Write the chemical equation for the reaction and determine the volume of
carbon dioxide gas produced. [Molar mass R = 46 g mol−1, molar volume of the gas at
room condition = 24 dm3 mol−1].

(c) State two compounds from Table 2.16 that react to produce ester.
Name and draw the structural formula for the ester formed.
(d) Acid X is used as a catalyst during the esterification reaction. When the concentrated acid X

is spilt on the marble floor, gas bubbles are formed. Name acid X and write the chemical
equation for the reaction.

100

Carbon Compound Chapter 2

2.4 ISOMERS AND NAMING BASED ON IUPAC
NOMENCLATURE

What is meant by structural isomerism? Standards

• Structural isomerism is a phenomenon where Pupils are able to:
a compound has the same molecular formula 2.4.1 describe structural isomerism.
but with two or more different structural formulae. 2.4.2 construct structure of isomers.
2.4.3 explain with examples the uses of
Isomers are molecules that have the same molecular
formula but different structural formulae. each homologous series in daily life.

• Structural isomerism can occur in several ways: Functional group isomerism is also
(i) Chain isomerism a type of structural isomerism. This
The isomers have different arrangements of carbon type of isomerism will be studied at
chains; either straight chain or branched chain. a higher level.
(ii) Position isomerism
The isomers have different positions of functional AR code
group on the same carbon chain.
• Figure 2.19 shows an example of structural isomerism
in butane, C4H10 and butene, C4H8.

Structural Isomerism

Chain Isomerism Position Isomerism
For example, isomer for C4H8
For example, the structural isomer of C4H10

H HHH H Chain H HHH H HHH
HC CC CH H CH
HH HC CC CHHC CC CH
H HHH HC CCH
HH H H

H HH

Straight chain Branch chain Double bond on Double bond on
the rst carbon the second carbon

• The isomers show: Figure 2.19 Example of structural isomer

(i) the same chemical properties because each isomer has
the same functional group.
(ii) the physical properties, such as melting point and • The isomers of alkanes are
boiling point, are different. The more branches there formed by chain isomers only.
are, the lower the melting point and boiling point are. • Isomers of alkenes, alkynes and
• Generally, the number of isomers of a molecule increases with alcohol are formed from chain
the increase of the number of carbon atoms in the molecule. isomers and position isomers.

101

Theme 2 Organic Chemistry

Steps in Drawing Isomers A ctivity 2L PAK 21
1. To draw isomers for alkanes, start by
1. Conduct this activity in groups.
connecting the carbon atoms in a straight 2. Scan the QR code to conduct an activity
chain followed by a branched chain. on constructing isomers for alkane,
2. To draw isomers for alkene and alkyne: alkene and alkyne.
(i) Start with a straight chain formula Constructing IsomersBab10/2
Nota6 B02-102a
and change the position of the http://kubupublication.com.my/Kimia/Tingkatan5/Nota6.pdf
double bond or triple bond to a
https://bit.ly/kpkt5n6

different carbon position.
(ii) Next, draw a structural formula with
a branched chain from each straight
chain that has different positions of
double or triple bonds.
Bab 10/2 Video25 B02-102b
Structural Isomers and the Naminghttp://kubupublication.com.my/Kimia/Tingkatan5/Video25.html
of Alkane According to the IUPAC
Nomenclature
https://bit.ly/kpkt5v25
Naming of Isomers According to the
Bab 10/2 Video26 B02-102c
IUPAC Nomenclature Structural Isomers and the Naminghttp://kubupublication.com.my/Kimia/Tingkatan5/Video26.html

• There are three parts in the naming of isomers: of Alkene According to the IUPAC
Nomenclature
(a) The prefix indicates the branch group, https://bit.ly/kpkt5v26

which is the alkyl group, with the general
formula CnH2n+1 that is attached to the longest carbon chain.
Example:

Molecular formula and -CH3 H -C2H5 H H -C3H7 H H H
structural formula
of alkyl group HC HC C HC CC
H HH H HH

Name of alkyl group Methyl Ethyl Propyl

(b) The root name shows the number of carbon atoms in the longest carbon chain.
(c) The suffix shows the homologous series.
Example: Mind What are the
Challenge advantages of
adhering to the
Homologous Alkane Alkene Alkyne Alcohol same system in the
series naming of organic

Suffix ‘ane’ ‘ene’ ‘yne’ ‘ol’ compounds?

• Steps for writing the name of a branched chain isomer are as follows:

Name writing sequence Prefix Root name Suffix
How to write
• Prefix and root names are “written close together”
• Number and name, write “–”
• Number and number, write “ , ”

102

Carbon Compound Chapter 2

Steps in Naming of Isomers According to the IUPAC Nomenclature

Step Example of alkane isomer Example of alkene isomer
1. Identify and name the
H HHHH
longest carbon chain, or HC H HCC C CH
the longest carbon chain HH
containing the functional H C C C H Branch H H
group for alkene. HH HC H
HC H Branch
⇒ Root name is obtained H
H
Longest carbon chain:
Longest carbon chain: 4 carbons
3 carbons Root name: Butene
Root name: Propane

2. Identify branch and H HHHH
functional group. HC H H C1 C2 C3 C4 H
HH
3. Number the carbon atoms H C1 C2 C3 H H
in the longest chain from HC H
one end so that: HH
• the branch gets the HC H H
lowest number for
alkane. H
• the functional group
gets the lowest number
for alkene.

4. State the position and The branches are: The branch is:
name of the branch, • Two methyl groups. • A methyl group on carbon
together with the • Both methyl groups are on
functional group. number 3.
carbon number 2.

⇒ Prefix is obtained from the Prefix: 2,2-dimethyl Prefix: 3-methyl
name and position of the
branch.

⇒ Suffix is obtained from the Homologous series is alkane. Homologous series is alkene.
homologous series. Suffix: “ane” Suffix: -1-ene (Double bond
is on the first carbon).

Name the isomer according to 2,2-dimethylpropane 3-methylbut-1-ene
the writing steps.

103

Theme 2 Organic Chemistry

Step Example of alkyne isomer Example of alcohol isomer
H 1H. lIHodnengHetisftycaanrbdonnamcheaitnhe
H C C cContCainHing a functional HH H
HCC C CH
grouHp. HC H
H HH
HC H HC H
H CC CH
H Branch H
Branch HH
⇒ Root name obtained OH
Longest carbon chain:
4 carbons Hydroxyl group
Root name: Butyne
Longest carbon chain:
HH 3 carbons
H C1 C2 C3 C4 H Root name: Propanol

2. Identify branch and H H
functional group. HC H
HC H
3. Number the carbon H
H HatomH s iHn the longest chain HH
Cff2ruonmCc3tiooCnn4ealeHgnrdo,uspo that the H 1 C 2C 3C H
gets the
H C1 HH
OH
HlowCest HHnumber.

4. StatHe the position and The branch is: The branch is:
name of the branch, and • One methyl on carbon • One methyl group on
functional group.
number 3. carbon number 2.
⇒ Prefix is obtained from the Prefix: 3-methyl Prefix: 2-methyl
name and position of the
branch.

⇒ Suffix is obtained from the Homologous series is alkyne Homologous series is alcohol
homologous series. Suffix: -1-yne (Triple bond is Suffix: -2-ol (Hydroxyl group
on the first carbon) is on the second carbon)
Name the isomer according to 3-methylbut-1-yne 2-methylpropan-2-ol
the writing steps.

Isomers for Alkane, Alkene and Alkyne

• Figure 2.20 shows the Mind
molecular model for Challenge

butane isomer, C4H10. Molecules can be rotated. Are

• Let us conduct Activity 2M these three structures different?

to improve your skills in CC
drawing and naming of
isomers according to the C CC C CC CC

IUPAC nomenclature. Figure 2.20 The molecular model for C C

butane isomer, C4H10

104

Carbon Compound Chapter 2

A ctivity 2M PAK 21

Carry out this activity in groups. Bab 10/2 Nota7 B02-104 Isomers of Alkane,
1. Draw the isomers and name them according to the http://kubupublication.com.my/Kimia/Tingkatan5/Nota7.pdf

IUPAC nomenclature for homologous series of alkane, Alkene and Alkyne
alkene and alkyne containing 4 and 5 carbon atoms. https://bit.ly/kpkt5n7
2. Share the findings in a Gallery Walk activity.

• Mhaevtehnanoeis, oCmH4e,rebtheacanues,eC2tHhe6 raendis propane, wC3aHy8 H HH HHH
only one HCH HCC H HCC C H
for the structural formulae of these molecules
to be constructed. H HH HH H
• Isomerism in alkane begins with butane, C4H10. CH4 C2H6 C3H8

Isomers for Alcohol

• Isomerism in alcohol homologous series starts with a molecule that has three carbon atoms.
• Similar to alkene and alkyne, isomerism in alcohol consists of chain isomers as well as position

isomers (different position of hydroxyl functional groups, OH).
• Table 2.17 shows the isomers of propanol, C3H7OH and butanol, C4H9OH.

Table 2.17 Propanol and butanol isomers

Alcohol Isomer Number
of isomer

HHH H OH H

Propanol, H C C C OH HCC CH 2
C3H7OH
HH H HH H

Propan-1-ol Propan-2-ol

H

Butanol, HHHH HHHH H HC H 4
C4H9OH HCC C CH HH
HC H
HH HCC C H

HCC C COH HH OH HCC C OH HO H

HH H H H HHH H

Butan-1-ol Butan-2-ol 2-methylpropan-1-ol 2-methylpropan-2-ol

A ctivity 2N PAK 21

Carry out this activity in groups.
1. Write the molecular formula of an alcohol with 5 carbon atoms.
2. Draw and name all possible isomers of the molecular formula in question 1.
Share all findings by carrying out the Stay-Stray activity.

105

Theme 2 Organic Chemistry

Uses of Homologous Series in Daily Life

Uses of Alkane and Alkene Malaysian Excellence
• Alkanes have high heat of combustion. Thus, Petronas' Success in Bab 10/2 Nota36 B02-106
http://kubupublication.com.my/Kimia/Tingkatan5/Nota36.html
the main usages of alkanes are for fuel and raw
materials in the petrochemical industry. Supplying LNG to the
• Alkenes are also used as raw materials in the World's Largest LNG Vessel.
petrochemical industry. https://bit.ly/kpkt5n36
• Figure 2.21 shows examples of the uses of members
of the homologous series of alkanes and alkenes.

Ethane HH HHHH
HC CH HC C C CH

HH HHHH

• Production of ethene from HH H
ethane to make detergents and plastics.
• Liquefied natural gas LNG that contains HC C C CH

ethane is used as fuel for powHer statHions.

CC

BuHtanHe H H H HH H H

HC CH HC C C CH

HH HHHH

• Production of fuel for lighterHs anHd HHHH
portable stoves. HC C C CH
HC CH
HHHH
•H LPGHcooking gas wHhenH mixeHdHwiHth
CproCpane.
HC C C CH

HH H

Ethene HH HH H

CC HC C C CH

HH H H HH HH EthanHol

•H PrCoduCctioHn of alcHohoCl, suCch Cas etChanHol.
• PrHoduHction of polythHeneH, poHlyvinHyl

chloride (PVC) and polystyrene.

ButH-1,3-dHiene HH H

CC HC C C CH

HH H

• Production of synthetic rubber to
manufacture tyres and hot water bags.

Figure 2.21 Examples of uses of alkanes and alkenes

106

Carbon Compound Chapter 2

Uses of Alcohol

• Photograph 2.9 shows the use of a hand sanitiser Photograph 2.9 Using hand sanitiser
containing more than 70% alcohol to prevent
COVID-19 infection. Why is alcohol used as a sanitiser?

• The physical properties of alcohol are suitable for the
production of materials for everyday use. Ethanol is a
type of alcohol that is widely used. Figure 2.22 shows
the various uses of alcohol.

Fuel Solvent

As fuel in clean fuel, bio fuel and As a solvent in
gasohol. • Paint, lacquer, dyes and printing ink.
• Cosmetics such as perfume, nail varnish,

cream and lotion.

Properties of alcohol Properties of alcohol
• Highly flammable, and combustion • Colourless, good organic solvent, miscible in

releases a lot of heat without soot. water and volatile.

Manufacturing sector Pharmaceutical products
Raw materials in the production of In the medical field
vinegar, explosives, polymer perspex • Antiseptics for injections, surgeries and
and fibre. general hygiene.
• Solvent for medicines such as cough medicine.

Properties of alcohol Properties of alcohol
• Chemically reactive. • Antiseptic, good organic solvent and volatile.

Figure 2.22 Various usages of alcohol

Bab 10/2 Video27 B02-107
Production and Useshttp://kubupublication.com.my/Kimia/Tingkatan5/Video27.html
of Ethanol
https://bit.ly/kpkt5v27 In Brazil, ethanol produced from the fermentation
of sugar cane is mixed with petrol as "gasohol" fuel.

107

Theme 2 Organic Chemistry

Effects of Misuse of Alcohol Causes addiction and State the implications
• iEnthaalcnoohl,oClic2Hb5eOveHraigsews.idLeolnygusteerdm mental disorders, of using science to
such as depression solve a problem
consumption of alcoholic beverages has and psychosis. or issue.
adverse effects on the function of the
central nervous system.
• Figure 2.23 shows the effects of misuse
of alcohol.

Inebriation, cognitive E ects of Birth defects if
impairment and having slow Misuse of Alcohol consumed by
physical re exes. Drunk drivers pregnant mothers.
may cause road accidents.

May cause cirrhosis of the liver, liver
failure, heart failure, gastritis, ulcer,
pancreatitis and oral cancer.

Figure 2.23 Effects of misuse of alcohol
(Source: MyHEALTH official portal. Ministry

of Health Malaysia)

Uses of Carboxylic Acid

• The most important carboxylic saacuidcei,skeetthcahnuopicanacdido,tCheHr3fCoOodOfHlavthoautriins gwsi.dely used as:
(i) food preservatives in chilli
(ii) raw materials with other chemicals to produce dyes, paints, pesticides and plastics.
• Methanoic acid, HCOOH is used in the rubber industry for coagulation of latex.
• Fatty acids are long-chain carboxylic acids used to make soap. Polymer:
• Carboxylic acid is also used to manufacture polymers, Condensation
namely polyester such as terylene and polyamide polymerisation
such as nylon. on page 147.

Pesticides Plastics T-shirt Chilli sauce

108

Carbon Compound Chapter 2

Usage of Ester

• Esters with small molecules easily evaporate and are fragrant, making them suitable for use in the
manufacturing of cosmetics and perfumes. Esters are also used as food flavourings. Table 2.18
shows examples of esters as food flavourings.
• Ethyl ethanoate, CfoHr 3oCrOgaOnCic2cHo5mispaonunesdtseri,n
Table 2.18 Examples of esters as food flavourings used as a solvent

Ester Flavour lotions, nail varnishes, lacquers and glue.

Methyl butanoate, C3H7COOCH3 Apple • Oils and fats are esters, formed between
fatty acids and glycerol that are used in
Penthyl ethanoate, CH3COOC5H11 Banana the production of soap.

Ethyl butanoate, C3H7COOC2H5 Pineapple • Polyester is a polymer for the production of
synthetic fabrics.

Consumer and industrial
chemistry:
Oils and fats, cleaning agents
and food additives on page 166.

Polyester fabric Food flavouring

A ctivity 2O Discussion Glue Soap

PAK 21

1. Carry out this activity in groups.
2. The petrochemical industry is thriving and contributes to the country’s economic growth. Plan a

forum to discuss the justification for the use of chemicals from the following homologous series:
(a) Alkane (b) Alkene (c) Alcohol (d) Carboxylic acid (e) Ester

Each group should send a representative as a forum panel. Conduct your forum by inviting
representatives from other classes as spectators.

2.4

1. Draw the structural formula for each of the following compounds:
(a) 2,3-dimethylbutane (b) 3,4-dimethylpent-1-ene (c) 3,4-dimethylheptane
(d) 4-methylhex-1-yne (e) 3-methylpentan-2-ol (f) 1,2-dibromohexane

2. Figure 2.24 shows the structural H HH

formulae of three hydrocarbons, HC H HH H HH HCC C CH
HCC C CCH H HH
X, Y and Z. H HH HCH
H HH
(a) Name the hydrocarbons HCC C CH HZ
Y
labeled X, Y and Z. H H
(b) Determine whether X, Y Figure 2.24
X

and Z are isomers. Give your reasons.

109

Theme 2 Organic ChemistryConcept
Map
110
CARBON COMPOUNDS

Organic Carbon Compounds Inorganic Carbon Compounds

Hydrocarbon Non Hydrocarbon Physical properties,
Saturated Hydrocarbon chemical properties
Unsaturated Hydrocarbon
and uses

Alkyne Homologous series

Source General formula CnnH=2n+01C,1O,2O,3…H

Homologous series n =Cn2H,32,n4-2… Isomerism General
formula
Alkane Cracking Alkene Hydration Alcohol Oxidation
Dehydration Esteri cation Carboxylic Acid
Hydrogenation General formula General formula

General formula General formula

n C=n1H,22n,+32… n =C2nH,3,24n… CnnH=2n1+,12O,3H… Ester

General formula

Physical properties, chemical Physical properties CmmH=20m,+11,C2O…OnCn=H12,n2+…1
properties, isomerism, uses and uses