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Published by Penerbit Ilmu Bakti, 2021-02-22 02:12:21

Chemistry

Chemistry

PENERBIT ILMU
BAKTI SDN. BHD.

Contents

FORM 4 4.7 Transition Elements 55

Summative Practice 4 58

Theme 1: The Importance of Chemistry Chapter

Chapter Introduction to Chemistry 1 5 Chemical Bond 60

1 5.1 Basics of Compound Formation 60

1.1 Development in Chemistry Field 5.2 Ionic Bond 62

and Its Importance in Daily Life 1 5.3 Covalent Bond 66
1.2 Scientific Investigation in
5.4 Hydrogen Bond 69
Chemistry 2
1.3 Usage, Management and 5.5 Dative Bond 72

Handling of Apparatus and 5.6 Metallic Bond 73

Materials 4
Summative Practice 1 7
PENERBIT ILMU 5.7 Properties of Ionic Compounds
BAKTI SDN. BHD.
and Covalent Compounds 74

Summative Practice 5 82

Theme 2: Fundamentals of Chemistry Theme 3: Interaction between Matter
Chapter Matter and the Atomic
Chapter Acid, Base and Salt 84
2 Structure 8
6

2.1 Basic Concepts of Matter 8 6.1 The Role of Water in Showing

2.2 Development of the Atomic Model 13 Acidic and Alkaline Properties 84

2.3 Atomic Structure 14 6.2 pH Value 88

2.4 Isotopes and their Uses 16 6.3 Strength of Acids and Alkalis 90

Summative Practice 2 19 6.4 Chemical Properties of Acids and

Chapter The Mole Concept, Chemical Alkalis 92

3 Formula and Equation 21 6.5 Concentration of Aqueous

Solution 95

3.1 Relative Atomic Mass and 6.6 Standard Solution 101

Relative Molecular Mass 21 6.7 Neutralisation 104

3.2 Mole Concept 23 6.8 Salts, Crystals and their Uses in

3.3 Chemical Formula 27 Daily Life 107

3.4 Chemical Equation 33 6.9 Preparation of Salts 109

Summative Practice 3 36 6.10 Effect of Heat on Salts 117

6.11 Qualitative Analysis 123

4Chapter The Periodic Table of Summative Practice 6 129
Elements 38
7Chapter Rate of Reaction 132
4.1 Development of the Periodic
38 7.1 Determining Rate of Reaction 132
Table of Elements
4.2 Arrangement in the Periodic 39 7.2 Factors Affecting Rate of
40
Table of Elements 42 Reactions 138
4.3 Elements in Group 18 48
4.4 Elements in Group 1 51 7.3 Application of Factors that Affect
4.5 Elements in Group 17
4.6 Elements in Period 3 the Rate of Reaction in Daily Life 145

7.4 Collision Theory 147

Summative Practice 7 151

ii

Theme 4: Industrial Chemistry Theme 7: Heat

8Chapter Manufactured Substances Chapter Thermochemistry 248
in Industry 154
3

8.1 Alloy and Its Importance 154 3.1 Heat Change in Reactions 248

8.2 Composition of Glass and Its 3.2 Heat of Reaction 251

Uses 158 3.3 Application of Exothermic and

8.3 Composition of Ceramic and Its Endothermic Reactions in Daily

Uses 160 Life 269

8.4 Composite Materials and their Summative Practice 3 271

Importance 162 Theme 8: Technology in Chemistry

Summative Practice 8 164

Chapter Polymer 273

FORM 5 4

Theme 5: Chemical Process 4.1 Polymer 273

4.2 Natural Rubber 279

Chapter Redox Equilibrium 166 4.3 Synthetic Rubber 287
PENERBIT ILMU
1 BAKTI SDN. BHD. Summative Practice 4 289

1.1 Oxidation and Reduction 166

1.2 Standard Electrode Potential 181 Chapter Consumer and Industrial

1.3 Voltaic Cell 184 5 Chemistry 290

1.4 Electrolytic Cell 190

1.5 Extraction of Metal from Its 5.1 Oils and Fats 290

Ore 205 5.2 Cleaning Agents 292

1.6 Rusting 209 5.3 Food Additives 299

Summative Practice 1 213 5.4 Medicines and Cosmetics 301

5.5 Application of Nanotechnology

Theme 6: Organic Chemistry in Industry 306

Chapter Carbon Compound 216 5.6 Application of Green

2 Technology in Industrial Waste

2.1 Types of Carbon Compounds 216 Management 309

2.2 Homologous Series 218 Summative Practice 5 311

2.3 Chemical Properties and SPM Model Test 313

Interconversion between

Homologous Series 226

2.4 Isomers and Naming according Answers 330

to IUPAC Nomenclature 241

Summative Practice 2 246

iii

5Chapter Theme 2: Fundamentals of Chemistry

Chemical Bond

5.1 Basics of Compound  3 Atoms of noble gases are inert which
Formation means they do not share, release
CHAPTER 5 FORM 4 or donate electrons with other
Stability of Noble Gases elements or between themselves.
PENERBIT ILMU
BAKTI SDN. BHD. 1 Elements naturally combine with 4 This is because atoms of noble gases
each other to form compounds. have achieved a stable duplet or
This is because the compounds octet electron arrangement.
formed are more stable than the
free elements. Stable Duplet and Octet Electron
Arrangements
 2 However, noble gases (Group 18)
are chemically unreactive and exist   1 Noble gases are stable due to their
as monoatomic gases in nature. electron arrangement.

He Ne Ar Kr

2 2.8 2.8.8 2.8.18.8

Duplet Octet

Diagram 5.1 Electron arrangement of noble gases

 2 Based on Diagram 5.1, it can be  5 Because of this, the energy of the
observed that helium, He has two electrons is very low and so, it is
electrons in its outermost shell difficult for the atoms to release
(valence shell). This is called a stable or receive electrons.
duplet electron arrangement.
Octet Rule
 3 The maximum number of electrons
that can be filled in the first shell  1 In order to achieve the stable octet
is two. Therefore, it is considered as electron arrangement, atoms in the
full. other main group in the Periodic
Table of Elements will react with
 4 For other noble gases (Ne, Ar, Kr, Xe one another in various ways.
and Rn), the valence shell contains
eight electrons. Thus, they have  2 The octet rule is what makes atoms
achieved a stable octet electron have a tendency to achieve the stable
arrangement. octet electron arrangement.

Keywords • Inert – Lengai • Valence shell – Petala valens
• Stability – Kestabilan

60

 3 However, if the outermost shell is the ➤
first shell, the maximum number of
electrons that can be filled is two. Na + Cl
Hence, the stable duplet electron
arrangement is achieved. 2.8.1 2.8.7 CHAPTER 5 FORM 4

 4 The duplet electron arrangement +
is as stable as the octet electron Na Cl
arrangement since there is no shell
occupied with electrons other than 2.8 2.8.8
the first shell. This is also said to
obey the octet rule. Diagram 5.2 Sodium atom transfers an electron
to chlorine atom to achieve stable octet electron
Visit https://youtu.be/
XGZIIwtIzyg to watch a video in arrangement
order to learn more about
duplet and octet electron  5 A covalent bond is formed when
arrangement. a non-metal atom combines with
another non-metal atom. Both
For educational purposes only atoms will share their electrons to
form a bond.
Chemical Bonds
 1 There are two ways for atoms of an  6 For example, the formation of
chlorine gas:
element to achieve the stable duplet PENERBIT ILMU
or octet electron arrangement: BAKTI SDN. BHD.Cl + Cl
(a) Transfer of electrons
(b) Sharing of electrons 2.8.7 2.8.7
 2 Those two ways will lead to the
formation of two types of chemical Cl Cl
bonds:
(a) Ionic bond 2.8.8 2.8.8
(b) Covalent bond
Diagram 5.3 Two chlorine atoms share a pair
Dynamic Info of electrons to achieve stable octet electron

The formation of chemical bonds only arrangement
involves the valence electrons.
Quick Check 5.1
 3 An ionic bond is formed between a
metal and a non-metal atoms. The 1 State two types of chemical bonds.
metal atom transfers electrons to 2 Why noble gases do not form
the non-metal atom.
compounds?
 4 For example, the formation of
sodium chloride compound:

61

5.2 Ionic BondCHAPTER 5 FORM 4 Formation of Ions

 1 Ionic bond is a type of chemicalPENERBIT ILMU  1 Ion is a charged particle that is
bond that is generated between BAKTI SDN. BHD. formed when an atom accepts or
two oppositely charged ions by loses its electrons.
transfer of electrons between the
atoms.  2 Thus, an ion is an atom or a group
of atoms that carries a positive
 2 Ionic bonds are always formed or negative charge. For instance:
between metal and non-metal Magnesium ion, Mg2+, hydrogen
atoms. ion, H+, iodide ion, I– and nitrate

 3 In an ionic bond, the metal  3 iAonn,eNutOra3l–.particle means it has an
atom releases electrons to form a equal number of protons (+) and
positively-charged ion called cation electrons (–). Therefore, the total
while the non-metal atom receives charge of the particle is zero.
the electrons to form a negatively-
charged ion called anion. Formation of Cations (Positively-

 4 The compound formed is called Charged Ions)
ionic compound.
 1 Cations are formed by metal atoms.
 5 Diagram 5.4 shows an example of an  2 Metal atoms from Groups 1, 2 and
ionic compound formed between a
sodium ion, Na+ and a chloride ion, 13 in the Periodic Table of Elements
Cl–. have 1, 2 and 3 valence electrons
respectively.
–  3 They form cations by releasing
+ the valence electrons in order to
achieve the stable octet electron
Na Cl arrangement.
 4 When the protons in the nucleus of
Diagram 5.4 Ionic bond between sodium ion, Na+ an atom outnumber the electrons
and chloride ion, Cl– after the valence electrons are
released, a positive ion is formed.

EXAMPLE +
  1 Formation of a cation with a charge of +1 K

Releases 1 electron
K

Number of protons = 19 Number of protons = 19
Number of electrons = 19 Number of electrons = 18
Charge = +1 (positive)
Charge = 0 (neutral)

K → K+ + e–
A neutral potassium atom loses an electron to form a potassium ion (cation) with the

charge of +1.

62

2 Formation of a cation with a charge of +2 2+
Ca
Releases 2 electrons
Ca

Number of protons = 20 Number of protons = 20 CHAPTER 5 FORM 4
Number of electrons = 20 Number of electrons = 18
Charge = +2 (positive)
Charge = 0 (neutral)

Ca → Ca2+ + 2e–
A neutral calcium atom loses two electrons to form a calcium ion (cation) with the

charge of +2.

3 Formation of a cation with a charge of +3

Releases 3 electrons 3+
Al Al
PENERBIT ILMU
BAKTI SDN. BHD.Number of protons = 13 Number of protons = 13
Number of electrons = 13 Number of electrons = 10
Charge = 0 (neutral) Charge = +3 (positive)

Al → Al3+ + 3e–
A neutral aluminium atom loses three electrons to form an aluminium ion (cation)
with the charge of +3.

Formation of Anions (Negatively-Charged Ions)

 1 Anions are formed by non-metal atoms except for the noble gases (Group 18).
  2 Non-metal atoms from Groups 15, 16 and 17 in the Periodic Table of Elements have

5, 6 and 7 valence electrons respectively.
 3 They form anions by accepting 3, 2 or 1 electrons in order to achieve the stable

octet electron arrangement.
 4 When the electrons outnumber the protons in the nucleus of an atom after

accepting electrons, a negative ion is formed.

EXAMPLE

  1 Formation of an anion with a charge of –1 –
Cl
Receives 1 electron
Cl

Number of protons = 17 Number of protons = 17
Number of electrons = 17 Number of electrons = 18
Charge = 0 (neutral) Charge = –1 (negative)

Cl + e– → Cl–
A neutral chlorine atom gains an electron to form a chloride ion (anion) with the charge
of –1.

63

  2 Formation of a cation with a charge of –2 2–
O
Receives 2 electrons
O

Number of protons = 8 Number of protons = 8
Number of electrons = 8 Number of electrons = 10
Charge = 0 (neutral) Charge = −2 (negative)

O + 2e– → O2–
A neutral oxygen atom gains two electrons to form an oxide ion (anion) with the

charge of –2.
CHAPTER 5 FORM 4

PENERBIT ILMU
BAKTI SDN. BHD.
Formation of Ionic Bonds
 1 Atoms release and accept electrons and form positive and negative ions.
 2 The oppositely charged ions are attracted together by a strong electrostatic

force of attraction which is known as ionic bond.

EXAMPLE

  1 Ionic bond between Group 1 metals and Group 17 elements

+ –

K + Cl K Cl

2.8.7 2.8.8 2.8.8

2.8.8.1

Ionic bond between a potassium atom (Group 1) and a chlorine atom (Group 7)

(a) The electron arrangement of potassium atom is 2.8.8.1. Potassium atom has
one valence electron.

(b) The potassium atom releases one electron to achieve the stable octet electron
arrangement. A potassium ion, K+ with the electron arrangement of 2.8.8 is
formed.

(c) The electron arrangement of chlorine atom is 2.8.7. Chlorine atom has seven
valence electrons.

(d) The chlorine atom receives one electron to achieve the stable octet electron
arrangement. A chloride ion, Cl– with the electron arrangement of 2.8.8 is
formed.

(e) The oppositely charged potassium ion, K+ and chloride ion, Cl– are attracted to
each other by a strong electrostatic force of attraction to form an ionic bond.

(f ) An ionic compound, potassium chloride, KCl is formed.

64

  2 Ionic bond between Group 1 metals and Group 16 elements

+ 2– +

Na + O + Na Na O Na



2.8.1 2.6 2.8.1 2.8 2.8 2.8

Ionic bond between two sodium atoms (Group 1) and an oxygen atom (Group 16) CHAPTER 5 FORM 4

(a) The electron arrangement of sodium atom is 2.8.1. Sodium atom has one
valence electron.

(b) The sodium atom releases one electron to achieve the stable octet electron
arrangement. A sodium ion, Na+ with the electron arrangement of 2.8 is
formed.

(c) The electron arrangement of oxygen atom is 2.6. Oxygen atom has six valence
electrons.

(d) The oxygen atom receives two electrons to achieve the stable octet electron
arrangement. An oxide ion, O2– with the electron arrangement of 2.8 is formed.

(e) The oppositely charged sodium ions, Na+ and oxide ion, O2– are attracted to
each other by a strong electrostatic force of attraction to form an ionic bond.

(f ) An ionic compound, sodium oxide, Na2O is formed.
PENERBIT ILMU
BAKTI SDN. BHD.
  3 Ionic bond between Group 2 metals and Group 16 elements

Mg + O 2+ 2–
Mg O

2.8.2 2.6 2.8 2.8

Ionic bond between a magnesium atom (Group 2) and an oxygen atom (Group 16)

(a) The electron arrangement of magnesium atom is 2.8.2. Magnesium atom has
two valence electrons.

(b) The magnesium atom releases two electrons to achieve the stable octet
electron arrangement. A magnesium ion, Mg2+ with the electron arrangement
of 2.8 is formed.

(c) The electron arrangement of oxygen atom is 2.6. Oxygen atom has six valence
electrons.

(d) The oxygen atom receives two electrons to achieve the stable octet electron
arrangement. An oxide ion, O2– with the electron arrangement of 2.8 is
formed.

(e) The oppositely charged sodium ion, Mg2+ and oxide ion, O2– are attracted to
each other by a strong electrostatic force of attraction to form an ionic bond.

(f ) An ionic compound, magnesium oxide, MgO is formed.

65

Dynamic Info

Predicting the Formula of Ionic Compounds
• The charge of the ion formed by an atom can be predicted based on its group in the

Periodic Table of Elements.
• Table 5.1 shows the formulae of ionic compounds formed by atoms of elements in

different groups.

Table 5.1 Formulae of ionic compounds

Group in Periodic Table of Elements Formula of ionic
CHAPTER 5 FORM 4 compound Example
Metal, P Non-metal, Q
PENERBIT ILMU
BAKTI SDN. BHD.Group 1Group 15P3Q Sodium nitride, Na3N
Group 1 Group 16 P2Q Sodium oxide, Na2O
Group 1 Group 17 PQ Sodium chloride, NaCl

Group 2 Group 15 P3Q2 Calcium nitride, Ca3N2
Group 2 Group 16 PQ Magnesium oxide, MgO

Group 2 Group 17 PQ2 Barium chloride, BaCl2
Group 3 Group 15 PQ Aluminium nitride, AlN

Group 3 Group 16 P2Q3 Aluminium oxide, Al2O3
Group 3 Group 17 PQ3 Aluminium bromide, AlBr3

Quick Check 5.2

1 How is an ionic bond formed? Cl Cl
2 Describe the formation of ionic
bond in sodium oxide. HOTS Analysing Diagram 5.5 Covalent bond between two chlorine
atoms
5.3 Covalent Bond
 4 There are three types of covalent
 1 Covalent bond is formed when bonds:
non-metal atoms combine with (a) Single covalent bond – sharing
each other to form a molecule. of one pair of electrons
(b) Double covalent bond – sharing
 2 During the formation of covalent of two pairs of electrons
bond, each non-metal atom (c) Triple covalent bond – sharing
contributes the same number of of three pairs of electrons
electrons to each other for sharing
to achieve the stable octet electron   5 The non-metal atoms combine with
arrangement. each other by contributing one, two,
three or four electrons for sharing
 3 Diagram 5.5 shows an example thus forming a covalent compound.
of a covalent compound formed
between two chlorine atoms.  6 Table 5.2 shows several examples of
covalent compound.

Keywords • Double bond – Ikatan ganda dua • Triple bond – Ikatan ganda tiga
• Single bond – Ikatan tunggal

66

Table 5.2 Examples of covalent compounds

Covalent compound Formula Covalent compound Formula

Hydrogen gas H2 Water H2O
CCl4
Oxygen gas O2 Tetrachloromethane SO2
NH3
Nitrogen gas N2 Sulphur dioxide

Carbon dioxide gas CO2 Ammonia CHAPTER 5 FORM 4

EXAMPLE (b) Each oxygen atom contributes
  1 Formation of fluorine molecule two electrons for sharing to
achieve the stable octet electron
(single covalent bond) arrangement and form a double
covalent bond.
F +F PENERBIT ILMUFF
BAKTI SDN. BHD. (c) The shared pairs of electrons
2.7 2.7 2.8 2.8 are attracted to the nucleus of
both atoms so, the double bond
Single covalent bond between two fluorine atoms holds the two oxygen atoms
together.
(a) The electron arrangement of
fluorine atom is 2.7. Chlorine (d) A covalent compound, oxygen
atom has seven valence gas, O2 is formed.
electrons.
  3 Formation of nitrogen molecule
(b) Each fluorine atom contributes (triple covalent bond)
one electron for sharing
to achieve the stable octet N+N NN
arrangement and form a single
covalent bond. 2.5 2.5 2.8 2.8

(c) The shared pair of electrons is Triple covalent bond between two nitrogen atoms
attracted to the nucleus of both
(a) The electron arrangement of
atoms so, the single bond holds nitrogen atom is 2.5. Nitrogen
the two fluorine atoms together. atom has five valence electrons.

(d) A covalent compound, fluorine (b) Each nitrogen atom contributes
gas, F2 is formed. three electrons for sharing to
achieve the stable octet electron
  2 Formation of oxygen molecule arrangement and form a triple
(double covalent bond) covalent bond.

O+ O OO (c) The shared pairs of electrons
are attracted to the nucleus of
2.6 2.6 2.8 2.8 both atoms so, the triple bond
Double covalent bond between two oxygen atoms holds the two nitrogen atoms
together.
(a) The electron arrangement of
oxygen atom is 2.6. Oxygen (d) A covalent compound, nitrogen
atom has six valence electrons. gas, N2 is formed.

67

Dynamic Info

The Lewis structure is a diagram which shows only the valence electrons of the atoms
represented by dots or crosses. The formation of covalent bonds can be represented by
Lewis structure as follows:

(a) H + H → H H or H—H (c) N + N → N N or N N

Hydrogen molecule Nitrogen molecule
(b) O + O → O O or O = O

Oxygen molecule
CHAPTER 5 FORM 4
Dynamic Info
PENERBIT ILMU
BAKTI SDN. BHD.
Predicting the Formula of Covalent Compounds
• The formula of a covalent compound can be predicted based on the valency of the

elements in the compound, in which the groups of the elements in the Periodic Table
are known.
• Valency of an atom means the number of electrons received or released to achieve a
stable octet electron arrangement.
• For example, the electron arrangement of chlorine atom is 2.7. Chlorine atom needs
one electron to achieve the stable octet electron arrangement. So, the valency of
chlorine atom is 1.
• Table 5.3 shows the formulae of covalent compounds formed based on the group and
valency of the elements.

Table 5.3 Formulae of covalent compounds

Elements in a compound Formula
of the
Group of Valency Group of Valency covalent Example
atom R atom S
compound

Group 14 4 Group 16 2 RS2 Carbon dioxide, CO2

Group 14 4 Group 17 1 RS4 Tetrachloromethane, CCl4
Group 15 3 Group 15 3 RS Nitrogen, N2
Group 15 3 Group 17 1 RS3 Nitrogen trifluoride, NF3
Group 16 2 Group 16 2 RS Oxygen, O2
Group 16 2 Group 17 1 RS2 Sulphur difluoride, SF2
Group 17 1 Group 17 1 RS Chlorine, Cl2

Comparison between Ionic Bond and Covalent Bond
Table 5.4 shows the comparison between ionic bond and covalent bond.

Table 5.4 Comparing ionic bond and covalent bond

Type of bond Ionic bond Covalent bond
Elements Between metal (Groups 1, 2 or Between non-metal (Groups 14,
involved 13) and non-metal (Groups 15, 15, 16 or 17) atoms
16 or 17) atoms

68

Electron Metal atom releases electrons Same or different non-metal CHAPTER 5 FORM 4
while non-metal atom receives atoms share pairs of electrons.
Type of the electrons (electron transfer).
particles Metal atoms form cations (positive Neutral molecules
produced ions) while non-metal atoms form Determine the number of
Predicting the anions (negative ions). electrons needed to achieve the
formula of the Determine the coefficient of the stable duplet or octet electron
compound charge of the ions and cross. arrangement and cross.
Example: Example:

Mg → Mg2+ + 2e– N needs 3 e– H needs 1 e–
Cl + e– → Cl–

Mg 2+ Cl –1

1 2 1 3
MgCl2 NH3
PENERBIT ILMU
Force of The positively-charged andBAKTI SDN. BHD.Atoms in a molecule are held
attraction negatively-charged ions are together by a strong covalent
held together by a strong bond whereas the molecules are
electrostatic force of attraction held together by a weak van der
in the ionic compound. Waals force.

Quick Check 5.3 between two separate molecules or
between parts in one molecule.
1 How is a covalent bond formed?
2 Describe the formation of Hydrogen H
bond
covalent bond. HOTS Analysing
3 Compare and contrast between H

ionic bond and covalent bond. O HO

HOTS Analysing H

5.4 Hydrogen Bond Covalent
bond
  1 Hydrogen bond is an interaction
or a force of attraction between Diagram 5.6 Hydrogen bond between two water
hydrogen atom and a highly molecules
electronegative atom such as
nitrogen, N, oxygen, O or fluorine, F.  4 Diagram 5.6 shows a hydrogen
bond formed between two water
 2 A hydrogen bond can also be said molecules. The hydrogen bond is
as a partial electrostatic force of represented by a dashed line.
attraction between a hydrogen atom
and an electronegative atom.  5 The two molecules involved in a
hydrogen bond do not need to be
 3 Hydrogen bonds can be formed identical.

Keywords  6 The strength of the hydrogen bond
• Hydrogen bond – Ikatan hidrogen depends on the electronegativity
of the atom. The higher the

69

electronegativity (F > O > N) of the atom, the stronger the hydrogen bond
formed.
 7 There are two requirements for the formation of hydrogen bond:
(a) The hydrogen atom is attached to a small and highly electronegative atom

(N, O or F).
(b) There is a lone pair of electrons on the electronegative atom.
 8 Hydrogen bonds are stronger than van der Waals forces but weaker than covalent
bonds.
 9 Hydrogen bonds are present in daily life. Some examples include:
(a) Wet hair sticks together because the protein molecules that make up a

hair strand form hydrogen bonds with water molecules which then form
hydrogen bonds with another water molecule on a different hair strand.
(b) The human DNA consists of hydrogen bonds that hold together the two
helix strands.
CHAPTER 5 FORM 4

PENERBIT ILMU
BAKTI SDN. BHD.
Effect of Hydrogen Bonds on Physical Properties of Substances

Table 5.5 shows the explanation on the physical properties of water that resulted
from the presence of hydrogen bonds.

Physical property Table 5.5 Physical properties of water
(a) Boiling point
Explanation
• Boiling point is the temperature at which the vapour pressure

of a liquid is equal to the atmospheric pressure.
• However, the presence of hydrogen bonds in the liquid makes it

more difficult for the molecules to escape from the condensed state.
Hence, more energy is needed to overcome the hydrogen bond.
• Therefore, a liquid that contains hydrogen bonds has a higher
boiling point.

Boiling point (K)
373 H2O

273 H2S H2Se H2Te
NH3 PH3 AsH3 SbH3

173

73 2 3 4 5 Period
Diagram 5.7 Boiling points of hydride compounds of Group 16

• Diagram 5.7 shows the effect that hydrogen bonds have on the
boiling point of water compared to other hydride compounds
of Group 16 elements.

• Due to the presence of hydrogen bonds between the water
molecules, the boiling point is higher than what it is supposed to be.

Keywords
• Lone pair of electrons – Pasangan elektron bebas

70

Physical property Explanation
(b) Density • Hydrogen bonds in water are responsible for the low density of ice.
• Water is one of the few substances that is less dense when it is

in the form of solid (ice) than it is as a liquid.
• In ice, the water molecules are surrounded by four other water

molecules (tetrahedral shape) that are linked with hydrogen
bonds.

PENERBIT ILMU CHAPTER 5 FORM 4
BAKTI SDN. BHD.
Diagram 5.8 Structure of ice

• Diagram 5.8 shows the structure of ice. The water molecules
arrange themselves in such a way to maximise the amount of
hydrogen bonding between them.

• Thus, it leaves large spaces between the water molecules and
gives rise to an open structure.

• This open structure of an ice is the reason for the fact that ice is
less dense than water at 0 °C.

• For most liquids, density increases as temperature decreases
but not in water molecules.

• For water, as temperature increases or decreases from 4 ºC, the
density of water decreases as shown in Diagram 5.9.

1.0000 –5 0 5 10 15 20 25 30 Temperature (oC)

0.9980 highest
density

0.9960 =
ice water

=
0.9200

Density (g cm–3)
Diagram 5.9 Graph of density vs temperature of water

• When ice melts and water is in the form of liquid, some of the
hydrogen bonds are broken, thus the molecules are closely
packed but they can slide and move around freely. Hence,
water has a higher density than ice (1.000 g cm–3).

71

Physical property Explanation
(c) Solubility • Compounds that can form hydrogen bonds with water molecules

are most likely to be soluble in water than those that cannot.
• The presence of hydrogen bonding between molecules

indicates that the molecules are polar thus, they will be soluble
in polar solvents such as water.
• For instance, ammonia and ethanol can dissolve in water through
hydrogen bonding. This indicates that they are polar molecules.
• Diagram 5.10 shows the hydrogen bond between water
molecule and ammonia molecule.
CHAPTER 5 FORM 4
Hydrogen H
PENERBIT ILMU bond
BAKTI SDN. BHD.
N H  O
H H

H

Diagram 5.10 Hydrogen bond between water and ammonia molecules

Dynamic Info at least one lone pair of electrons
in its valence electron.
Water is a very good solvent. Water is  4 Acceptor is the atom that accepts
known as the universal solvent because the electron pair. This atom has
it can dissolve almost everything. vacant orbitals in its outermost shell.
 5 Diagram 5.11 shows the dative
Quick Check 5.4 bond between water molecule,
Hdhyi2adOgrroaaxnmodn, ihauymddraiootginvee,nHbi3ooOnn+,d.HIni+satosshimfoowprmlne
1 Define hydrogen bond. by an arrow. The arrow originates
2 Are there hydrogen bonds formed from the atom which donates the
between ethanol molecules, C2H5OH? lone pair (donor) and points to the
atom which receives it (acceptor).
5.5 Dative Bond
Lone pair Dative bond Donor +
  1 Dative bond is a covalent bond in
which only one atom contributes H O + H+ H OH HOH
both electrons for bonding.
H HH
 2 Dative bonds are also known as Acceptor
coordinate bonds or dipolar bonds.
Unequal sharing of electrons occurs Diagram 5.11 Formation of dative bond in
because the atoms have different hydroxonium ion, H3O+
electronegativities.
 6 Another example of dative bond is
 3 Donor is the atom that donates the
shared electron pair. It must have when ammonia cghalso, rNidHe3 is mixed
with hydrogen gas, HCl
Keywords
• Dative bond – Ikatan datif where white fumes of ammonium

• Coordinate bond – Ikatan koordinat

72

clohnloeridpea,irNHof4Cel leacretrofonrsmeodn. The Nucleus + + + 2+ Nucleus
the Valence
electron + + + 2+
nitrogen atom in the ammonia 2+ 2+
+++
molecule forms a dative covalent 2+ Valence
Group 1 metal 2+ 2+ electron
bond with the hydrogen ion, H+
2+
in the hydrogen chloride molecule
2+
(Diagram 5.12).
Group 2 metal

H Lone pair H Dative + Diagram 5.13 Sea of electrons
bond H
 4 In contrast with the covalent bond, CHAPTER 5 FORM 4
H N + H+ H N H HN H a metallic bond is non-directional
due to the localised sea of electrons.
H HH
 5 The strength of a metallic bond
Diagram 5.12 Formation of dative bond in depends on two factors:
ammonium ion, NH4+ (a) The atomic size of the metal
atom – the smaller the atomic
 7 Compounds that form dative bonds size, the stronger the metallic
have the same characteristics as bond.
compounds with covalent bonds. (b) The number of valence
PENERBIT ILMU electrons in the metal atom –
Quick Check 5.5 BAKTI SDN. BHD. the metallic bond is stronger
for atoms that have a higher
1 State another name for dative bond. number of valence electrons.
2 Describe the formation of Thus, the electrostatic force of
attraction between electrons
hydroxonium ion through and positive ions increases
the formation of dative bond from metals in Group 1 to
hbyedtwroegeennwioante, rHm+. oHleOcTuSleAn, aHlys2iOng and Group 13. For example, the
metallic bond in aluminium is
5.6 Metallic Bond stronger than in sodium.

 1 The properties of metals cannot Properties of Metals
be explained in terms of ionic and
covalent bonds.  1 Metals are malleable and ductile.
(a) When a metal can be flattened
  2 Metallic bond is the electrostatic into a sheet without cracking,
force of attraction between the it is said to be malleable.
positively-charged metal ions and (b) A metal is also ductile due to its
the ‘sea’ or ‘cloud’ of delocalised ability to be pulled into a wire.
electrons. (c) These two properties are due
to the ability of metal ions to
 3 In metals, the valence electrons slide past one another through
are no longer associated with a the sea of delocalised valence
particular metal atom. They are electrons. The metal ions move
free to move throughout the solid. to a new position without
Hence, the valence electrons are breaking the structure.
delocalised (Diagram 5.13) and so,
the metal atoms are ionised.

Keywords • Delocalised electron – Elektron dinyahsetempatkan
• Metallic bond – Ikatan logam
• Sea of electrons – Lautan elektron

73

 2 Metals are good electrical 5.7 Properties of Ionic
conductors. Compounds and
(a) Metals can conduct electricity Covalent Compounds
due to the presence of
delocalised electrons. Structure and Properties of Ionic
(b) When force is applied, the
delocalised valence electrons Compounds
charged flow from the negative
terminal to the positive  1 Diagram 5.15 shows the alternate
terminal. orderly arrangement of positive
and negative ions in a solid ionic
compound.
CHAPTER 5 FORM 4
Negative Positive Na+ Cl– Na+ Cl–
PENERBIT ILMUterminalterminal Cl– Na+ Cl– Na+
BAKTI SDN. BHD. Na+ Cl– Na+ Cl–
+ + +++ Cl– Na+ Cl– Na+

- + + ++ + +

+ + +++

+ + ++ +
Electron Metal
Diagram 5.15 Arrangement of cations and anions
Diagram 5.14 Electrical conductivity of metal in sodium chloride

 3 Metals are good heat conductors.  2 The ionic bond between the ions can
(a) The presence of delocalised form a giant ionic lattice structure
valence electrons enables as shown in Diagram 5.16.
metals to conduct heat.
(b) Collisions among the Na+ Cl–
delocalised electrons produce
heat. Thus, electrons from the Cl– Na+
high temperature region move
rapidly and randomly to the Giant lattice structure Strong electrostatic
lower temperature region and force formed between
transfer heat energy to the
other electrons throughout the positive and
the metal. negative ions

Quick Check 5.6 Diagram 5.16 Electrostatic force of attraction in
giant lattice structure
1 Define metallic bond.
2 Delocalised electrons play an  3 The ionic bond is a strong
electrostatic force of attraction
important role in metallic bonds. between the positive and negative
What is meant by delocalised ions that are next to each other in
electrons? the lattice.
3 State three properties of metals.
 4 Diagram 5.17 shows the physical
properties of ionic compounds.

Keywords
• Giant lattice structure – Struktur kekisi gergasi

74

Bubble Map

Exist as crystal
solids at room
temperature

Only High melting CHAPTER 5 FORM 4
conduct point and boiling
electricity in the point due to strong
molten state and forces of attraction
aqueous solution,
but not in the
solid state

Almost all are BAKTI SDN. BHD. Hard but
soluble in water brittle
but insoluble in
organic solvents – The bonds are
broken along the
planes of ions with

applied force

Diagram 5.17 Physical properties of ionic compounds

Structure and Properties of CovalentILMUStrong H — N|H—H HH—| N—H Weak van
Compounds covalent H — N|—H H der Waals
There are two types of covalentPENERBIT bond in the force
compounds: molecule between the
(a) Simple molecular compounds molecules
(b) Giant molecular structures H— N|H—H

Simple molecular compounds Diagram 5.18 Arrangement of molecules in a
 1 In covalent compounds, the atoms covalent compound

in the molecule are bonded by  3 The following are the physical
strong covalent bonds whereas the properties of simple molecular
molecules are then held together covalent compounds.
by the weak van der Waals forces (a) They have low melting points
(intermolecular forces). because the intermolecular
 2 Thus, most covalent compounds are forces between the simple
made up of independent molecular covalent molecules are very
units (Diagram 5.18). weak.
(b) They are poor electrical
Keywords conductors in any physical
• Molten state – Keadaan leburan
• Brittle – Rapuh

75

state since there are no  2 Diamonds, silica (sand) and graphite
freely moving ions to carry are examples of giant molecular
charge. They exist as neutral compounds.
molecules.
(c) Small molecules dissolve  3 Table 5.6 shows the explanation
in organic solvents to form on the properties of diamonds and
solutions. graphite which are both made up of
carbon atoms (allotropes).

Giant molecular compounds Dynamic Info

(Macromolecules) Allotropes are different forms of the
same element in the same physical state.
 1 Macromolecules are giant covalent
molecules with extremely large
molecular lattice.
CHAPTER 5 FORM 4
Table 5.6 Physical properties of carbon allotropes
PENERBIT ILMU
BAKTI SDN. BHD.Diamond Graphite
(a) A diamond crystal is a giant (a) In graphite, the carbon atoms are arranged

molecule. in hexagonal rings in layers. Each layer is
(b) Diamond is the hardest natural of one atom thickness.
(b) Graphite is slippery as the carbon atoms only
substance and so it is used as a form three covalent bonds instead of four.
cutting tools. This makes graphite useful as a lubricant.
(c) Diamond is very hard because each (c) That creates sheets of carbon atoms that
carbon atom forms four covalent are free to slide over one another.
bonds in a very rigid and strong (d) Due to the presence of strong covalent
giant covalent structure. bonds, graphite has a high melting point.
(d) Those strong covalent bonds give The bonds require a lot of heat energy to
diamond a very high melting be broken.
point. A lot of heat energy is (e) The presence of free electrons (unbounded
needed to break the bonds. electrons) allows graphite to conduct
(e) Diamond cannot conduct electricity, so it is commonly used as
electricity because there are no electrodes.
free mobile ions present in it.

Diagram 5.19 Three-dimensional structure Diagram 5.20 Three-dimensional structure of graphite
of diamond

 4 Physical properties of macromolecules:
(a) They have high melting point and boiling point.

Keywords
• Giant molecules – Molekul gergasi

76

(b) They cannot conduct electricity in all states even when molten (except for
graphite).

(c) They are usually soluble in organic solvents but not in water.

Comparison between properties of ionic compounds and covalent compounds

Table 5.7 Comparison between physical properties of ionic compounds and covalent compounds

Type of Ionic compounds Covalent compounds
compound

Electron + – NN CHAPTER 5 FORM 4
arrangement Na Cl
diagram

Type of forcesPENERBIT ILMU Sodium chloride Nitrogen
between BAKTI SDN. BHD.
particles Strong electrostatic forces of Strong covalent bonds between
Melting point attraction between the ions atoms but with weak van der
and boiling Waals forces (intermolecular
point • High forces) between the molecules
• Positive and negative ions • Low (except for giant
Electrical
conductivity are held together by strong molecular compounds that
Solubility electrostatic forces of have high melting point and
attraction boiling point, e.g. silicon
Volatility • Large amount of heat energy dioxide)
Examples is needed to overcome the • Weak van der Waals forces
forces between the molecules
• Small amount of heat energy is
Conduct electricity only in needed to overcome the forces
the molten state and aqueous Cannot conduct electricity in
solution because there are freely all states because they consist
moving ions that carry charges of neutral molecules (no freely
• Most are soluble in water but moving ions)
Soluble in organic solvents but
insoluble in organic solvents insoluble in water
• This is because of the
High
polarisation of water (there are Ethanol, acetamide, naphthalene,
negative and positive ends in tetrachloromethane, hexane,
a water molecule) benzene

Low
Sodium chloride, lead(II)
bromide, copper(II) sulphate,
calcium oxide, calcium carbonate

Dynamic Info

Organic solvents (ether, alcohol, benzene, tetrachloromethane and propanone) are
covalent compounds that exist as liquids at room temperature.

77

Experiment 5.1

Aim:   3 Turn the switch on and observe the
To study the differences between the bulb. Record the observation.
properties of ionic compounds and covalent
compounds   4 Heat the lead(II) bromide solid strongly
until it melts completely. Turn the
Problem statement: switch on again and record the
What are the differences between the observation.
properties of ionic compounds and covalent
compounds?   5 Repeat steps 1 to 4 by replacing lead(II)
CHAPTER 5 FORM 4 bromide with naphthalene.
Apparatus:
PENERBIT ILMUCrucible, boiling tube, spatula, tripod stand,  6 Using the same set-up, put three
BAKTI SDN. BHD.pipe-clay triangle, carbon electrode, battery,spatulas of magnesium chloride
light bulb, switch, connecting wire, Bunsen crystals into a crucible.
burner
  7 Turn the switch on and observe the
Materials: bulb. Record the observation.
Magnesium chloride, naphthalene, hexane,
cyclohexane, lead(II) bromide, sugar,   8 Add distilled water to the magnesium
distilled water chloride. Stir the mixture with a glass
rod until all of it is dissolved completely.
(A) Electrical conductivity of compounds
Hypothesis:   9 Turn the switch on again and record
Ionic compounds conduct electricity in the observation.
the molten state and in aqueous solutions
but not in the solid state whereas covalent 10 Repeat steps 6 to 9 by replacing
compounds cannot conduct electricity in magnesium chloride with sugar.
any state.
(B) Solubility of compounds
Variables: Hypothesis:
(a) Manipulated: Types of compounds Ionic compounds dissolve in water but
(b) Responding: Electrical conductivity not in organic solvents whereas covalent
(c) Fixed: Carbon electrodes compounds dissolve in organic solvents
but not in water.
Procedure:
Variables:
(a) Manipulated: Types of compounds
(b) Responding: Solubility in water and

organic solvents
(c) Fixed: Water and organic solvents

Procedure:

Batteries

Switch Bulb

Carbon Distilled Cyclohexane
electrodes water
Lead(II)
Crucible bromide Magnesium
Pipe-clay solid chloride
triangle
Heat   1 Fill two boiling tubes with 5.0 cm3
of distilled water and cyclohexane
  1 Put three spatulas of lead(II) bromide respectively.
solid into a crucible.
  2 Add half a spatula of magnesium
  2 Dip two carbon electrodes in the chloride crystals into each boiling tube
lead(II) bromide solid and connect the and shake them.
batteries and switch with connecting
wires to complete the circuit.   3 Observe and record the solubility of
magnesium chloride in both water and
cyclohexane.

78

  4 Repeat steps 1 to 3 by replacing Procedure:
magnesium chloride with naphthalene
and hexane respectively.

(C) Melting point and boiling point of Magnesium Distilled
compounds chloride xxxxxxxxxxxxxxxxxxxxxxxx water
Naphthalene
Hypothesis:
Ionic compounds have high melting Heat CHAPTER 5 FORM 4
point and boiling point whereas covalent
compounds have low melting point and
boiling point.

Variables:   1 Put half a spatula of magnesium
(a) Manipulated: Types of compounds chloride crystals and naphthalene solid
(b) Responding: Melting point and boiling into two separate boiling tubes.

point   2 Heat both boiling tubes in a water bath.
(c) Fixed: Quantity of compounds, time of   3 Observe and record any change in the

heating physical state of the compounds.
PENERBIT ILMU
Results: BAKTI SDN. BHD.

(A) Electrical conductivity of compounds

Compound Physical state Observation Inference
Conducts electricity in
Lead(II) Solid The bulb does not light up the molten state but
bromide Molten The bulb lights up not in the solid state
Does not conduct
Naphthalene Solid The bulb does not light up electricity in any state
Magnesium Molten The bulb does not light up
chloride Solid The bulb does not light up Conducts electricity in
aqueous solution but
Aqueous solution The bulb lights up not in the solid state
Does not conduct
Sugar Solid The bulb does not light up electricity in any state

Aqueous solution The bulb does not light up

(B) Solubility of compounds

Compound Water Solubility
Soluble Cyclohexane (organic solvent)
Magnesium chloride Insoluble
Naphthalene Insoluble
Soluble

(C) Melting point and boiling point of compounds

Compound Observation Inference
Physical state Action of heat

Magnesium Solid No change Has high melting point and
chloride boiling point

Naphthalene Solid Melts rapidly Has low melting point and
boiling point

79

Discussion:CHAPTER 5 FORM 4 bond. Naphthalene is a covalent
  1 Lead(II) bromide and magnesium compound with low melting point
PENERBIT ILMU and boiling point. This is because less
chloride in the solid state cannotBAKTI SDN. BHD. heat energy is required to break the
conduct electricity as the ions are weak intermolecular forces between
fixed in their position. When lead(II) the molecules.
bromide is molten, the ions are then
free to move and able to carry electrical Conclusion:
charge. When magnesium chloride   1 Lead(II) bromide and magnesium
is dissolved in water, the aqueous
solution can conduct electricity due chloride are ionic compounds. They
to the presence of freely moving ions. do not conduct electricity in the solid
Naphthalene and sugar do not conduct state but do conduct electricity in the
electricity in any state as they consist molten state or in aqueous solution
of neutral molecules. due to the presence of freely moving
  2 Galvanometers and ammeters can be ions. Meanwhile, naphthalene and
used to replace the bulb. The deflection sugar which are covalent compounds
of the needle will show the flow of do not conduct electricity in any state
current thus the electrical conductivity. due to the absence of freely moving
  3 Magnesium chloride is soluble in ions.
water as it can form bonds with   2 Magnesium chloride (ionic compound)
water but insoluble in organic is soluble in water but insoluble in
solvents. Naphthalene is soluble in organic solvents. Naphthalene
organic solvents but not in water as (covalent compound) is insoluble in
its molecules are held together by van water but soluble in organic solvents.
der Waals forces.   3 Magnesium chloride, an ionic
  4 The melting point and boiling point compound, has high melting point and
of magnesium chloride, an ionic boiling point whereas naphthalene, a
compound, is high due to the strong covalent compound, has low melting
electrostatic force of attraction point and boiling point. It can also
between the positive and negative be deduced that ionic compounds
ions in the compound. A lot of heat are non-volatile whereas covalent
energy is needed to break the ionic compounds are volatile.

Uses of Ionic Compounds and Covalent Compounds in Daily Life

Uses of ionic compounds

 1 Ionic compounds are widely used in daily life such as in the industrial, agricultural
and medicinal sectors.

 2 Table 5.8 shows some examples of ionic compounds and their uses.

Table 5.8 Uses of ionic compounds

Ionic compound Use

Sodium chloride (table salt) Widely used as seasoning and preservatives
in the food industries

Sodium bicarbonate (baking soda) Used in cooking and as antacids
Sodium carbonate (washing soda) Used in cleaning agents

Sodium hypochlorite An active ingredient in household bleach

Magnesium sulphate Used in the purification of water

80

   Baking powder Chalk Detergent Table salt   CHAPTER 5 FORM 4

Diagram 5.21 Uses of ionic compounds

Uses of covalent compounds

 1 Many covalent compounds exist as volatile liquids at room temperature. This
is due to their low melting point and boiling point.

 2 In daily life, liquid covalent compounds are mostly used as solvents. They are
known as organic solvents which are commonly used to prepare solutions and
to clean stains that cannot be removed by water.

 3 Table 5.9 shows some examples of uses of covalent compounds.
PENERBIT ILMU
Covalent compound BAKTI SDN. BHD.Table 5.9 Uses of covalent compound
Alcohols
Turpentine Use
Petrol and kerosene As solvents in medicine
Ethers To dissolve paints
Esters As solvents to remove oils and grease
As solvents in the extraction of chemicals in aqueous solutions
To make perfumes

Portable gas Perfume Sugar Tyre

Diagram 5.22 Uses of covalent compounds

Quick Check 5.7

1 Compare the electrical conductivity of ionic compounds and covalent compounds.
2 Give two uses of ionic compounds and covalent compounds in the industrial sector.
3 State the properties of a giant molecule based on its chemical bond.

81

Summative Practice 5

 1 Which of the following atoms I Q+
II P
forms an anion? III R
A Sodium IV R2+
B Helium
C Oxygen A I and II
B I and III
C II and IV
D III and IV
CHAPTER 5 FORM 4 D Aluminium

PENERBIT ILMU 2 Which of the following
BAKTI SDN. BHD.
compounds is formed by sharing

of electrons?  6 Which of the following compounds
A Magnesium hydroxide
B Carbon dioxide gas contains hydrogen bond?
A HCl
C Sodium chloride B
D Krypton C NCHlH22S3
D
 3 Which substance is an ionic

compound?  7 Table 2 shows the group for
A Ammonia
B Zinc oxide elements P and Q.

C Methane gas Element Group
D Hydrogen gas P 17
Q 2
 4 Element M forms two types of

chloride, MCl2 and MCl3. What is M?
A Iron
B Zinc
C Lead Table 2
D Copper
What is the chemical formula
 5 Table 1 shows the proton number and the type of bond for the
compound formed when element
for elements P, Q and R. P reacts with element Q?

Element Proton number A Chemical Type of
P 10 B formula bond
Q 11 C
R 12 D P2Q Covalent
P2Q Ionic
Table 1 PQ2
PQ2 Covalent
Which of the following particles Ionic
contains 10 electrons?

82

 8 Which of the following are factors molten state but not in the solid CHAPTER 5 FORM 4
that affect the strength of metallic
bond? state. Which of the following is
compound A?
I Number of valence electrons A Hydrochloric acid
II Melting point B Lead(II) bromide
III Atomic size C Ammonia
IV Heat conductivity D Ethanol

A I and II 12 The electron arrangement of atom
B I and III X is 2.8.2 and of atom Y is 2.6.
C II and IV Elements X and Y react to form a
D III and IV compound. Which of the following

 9 Which of the following is the is true about the reaction?
property of hexane? A Atom Y donates one electron
A Low volatility B Atom X receives two electrons
B Dissolve in water C A covalent compound is formed
C Can conduct electricity D The compound formed has the
D Has high boiling point
chemical formula of XY
10 Sodium atom can react with PENERBIT ILMU
chlorine atom to form sodium BAKTI SDN. BHD.13 Diagram 1 shows the standard
chloride, NaCl. Which of the representation for atoms of two
following represents the electron elements, X and Y.
arrangement of the compound?
A X Y7 16

Na Cl 3  8

Diagram 1

B Cl Which of the following represents
the compound formed when
Na element X reacts with element Y?
A 2–

+

XY

C +
Cl B

Na – YXYX
Cl
D 2–
C +
+
Na + YX

X

11 Compound A has high melting D
point and boiling point. It
can conduct electricity in the XYX



83


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