c5 tahap 2 noraidah

4541 / CHEMISTRY MODUL P3T (TAHAP 2 )

Chapter 5 : CHEMICAL BONDS

A Formation of compounds

1. Atoms of other elements tend to achive the stable duplet / octet electron arrangement through the formation of chemical bonds except noble gas.

2. All Noble gases are very stable, inert and chemically unreactive because ……………………………………………………………………………………………………………….

3. Complete the diagram below :

B Ionic Bond

JPNT 2009 CHAPTER 5 :CHEMICAL BONDS

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CHEMICAL BONDS formed by

Ionic Bond Covalent BondType of Bond

Sharing of electron

Ionic Bond

Formed through

Donate electron

To achieve …………..………………………………………………

Receive electron

Metal Non-metal

Transfering of electronbetween….


Formation of ions

1. An atom donates electron forms a ……………………..….. ion (cation)

donates one electron

2.1 2 Lithium atom lithium ion

2. An atom receives / accepts electron forms a ……………………..….. ion (anion)

accepts one electron

2.7 2.8 Fluorine atom Fluoride ion

3.

Cation is a …………………………………………………………………

Anion is a …………………………………………………………………


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Donates electron

Accepts electron

Neutral atom

Cation Anion

+ _

+

_

Duplet electron arrangement

Octet electron arrangement

positive

negative

positively-charged ion

negatively-charged ion


Example 1 :

Aluminium atom, Al [ Proton number = 13 ; Nucleon number = 27 ]


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Becomes an …………………..

An aluminium atom ………………………………………….. to achieve the stable octet electron arrangement [ 2.8 ]

Draw the formation of an aluminium ion, Al3+

Write the equation to represent the formation of an aluminium ion Al3+

Al →

Electron arrangement : …………


Example 2 :

Oxygen atom, O [ Proton number = 8 ; Nucleon number = 16 ]

Forming of Ionic Bonds

1. Ionic compounds are formed when a …………… react with a ..............................

2. During the formation of ionic bonds : electrons are transfered from the …………………. atom to the ………………….

atom.

the …………………. atom donates its valence electrons to form a

…………………. ion while the …………………. atom receives electrons to form a

…………………. ion.

3. The positive and negative ion are held together by ………………………………. between the oppositely-charged ions. The attractive force between ions is called ionic bond or electrovalent bond.


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Becomes an ………………….

The oxygen ……….. receive/accept ………….. to …………………………………………………………………….

Draw the formation of an oxide ion, O2-

Write the equation to represent the formation of an oxide ion, O2-

O + ……e → …………..

Electron arrangement : ……………


Example : sodium chloride, NaCl [ Proton number : Na = 11 ; Cl = 17 ]


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to achieve the stableoctet electron arrangement

NaCl

Electron arrangement

Na Cl

The equations to represent the formation of ions :

Na → Na+ + e

Cl + e → ……….

Formula of sodium chloride is ……… …………….

The diagram of sodium chloride compound, NaCl formed :

Na

Cl

-


Activity :-

Element Proton numberElectron

arrangement

Mg 12

Cl 17

Electron arrangement of magnesium atom is …………………………….

Magnesium atom has …………. valence electrons. By releasing/receiving* these

electrons, magnesium atom forms magnesium ………………to achieve a stable

……………………. electron arrangement i.e. ……………………………..

Mg → ………………………………………………

Electron arrangement of chlorine atom is ………………………

Chlorine atom has ……………. valence electrons. By receiving ……………….

electron, chlorine atom forms ……………………………. with an

………………………. electron arrangement i.e. ……………………………..

Cl + …………. → ……………………

Mg2+ ions attract Cl- ions with strong electrostatic forces. The bond formed is called ionic bond.

Electronic diagram of magnesium chloride is :

Formula of sodium chloride is …………………………….


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C Covalent Bonds

1. Covalent bonds are formed when non-metal atoms share its valence electrons to

achieve stable ………………………………. electron arrangement.

[atoms from element in Group 14, 15, 16 and 17]

2. The product formed from the sharing of electrons between atoms is called a neutral

……………………..

3. The force that exist between molecules is called ………………….……………………..

This force is …………………….. between small molecules and becomes stronger

when the size of molecules ……………………...


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Sharing of electrons

Covalent Bond

Formed through

To achieve the stable octet / duplet

electron arrangement

Type of covalent bonds

Single bond

Example :

Water,H2O

Double bond

Example :

Carbon dioxide,CO2

Triple bond

Example :

Nitrogen gas,N2

Single covalent bond

of electron Transfering


Forming of Covalent Bonds

Example : Methane [ Proton number of H = 1, C = 6 ]


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to achieve the octet / duplet electron arrangement

Methane


C H

…………. carbon atom sharing its valence electrons with

………… . hydrogen atoms, formed covalent bond.

Each carbon atom sharing ……… pair of electrons with each

hydrogen atom, formed ……………….. covalent bond.

The formula of methane is ………..……………

Need ………… electrons Need ………… electron

CH

H

H

H


Activity 4 :-

Forming of carbon dioxide[ Proton number of C = 6 ; O = 8 ]


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…………. carbon atom sharing its valence electrons with

………… . oxygen atoms, formed a covalent bond.

Each carbon atom sharing ……… pairs of electrons with each

oxygen atom, formed …………..….. covalent bond.

The formula of carbon dioxide is ………………………

to achieve the stable octet electron arrangement

Carbon dioxide


C O

Need ………… electrons Need ………… electrons

2.4 2.6

4 2

1

2

2

double

CO2


COMPARISON BETWEEN THE FORMATION OF IONIC AND COVALENT BONDS


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Ionic bonding Covalent bonding

Similarity

Atoms achieved the stable electronic configuration/electron arrangement with an octet or duplet after the formation of bonds.

Differences

Involves ……………… of electrons from metal atom to non-metal atom.

Positively ………….. and negatively charged ions are formed.

Strong ……………… holds oppositely charged ions together.

Involves the ……………. of electrons between non-metals atoms.

………………… are formed.

Weak ……………..of attraction exist between the molecules.


The properties of Ionic Compounds and Covalent Compounds

Types of compound

Types of chemical bond

Types of particles that are present

Melting and boiling points

Solubility in water

Solubility in organic solvents

Electrical conductivity

Physical state at room temperature


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Ionic Covalent

electrostatic Van der Waals

ions molecules

high low

soluble insoluble

insoluble soluble

Cannot conduct electricity in solid state; conduct electricity in molten and aqueous solution state

Cannot conduct electricity in any physical state

solid liquid and gas


ACTIVITY 1

1. The electron arrangement of atom X is 2.8.5 and atom Y has 2 valence electrons. What is the type of bond and formula of compound formed between X and Y?Susunan elektron bagi atom X ialah 2.8.5 dan atom Y mempunyai 2 elektron valens. Apakah jenis ikatan dan formula sebatian yang terbentuk antara X dan Y?

A

B

C

D

Type of bond Jenis ikatan

Formula of compound Formula sebatian

Ionic Ion

XY2

Ionic Ion

Y3X2

Covalent Kovalen

X2Y3

Covalent Kovalen

YX2

2. Diagram 8 shows the electron arrangement of a carbon dioxide molecule.Rajah 8 menunjukkan susunan elektron bagi molekul karbon dioksida.

Which of the following is true?

Antara berikut yang manakah benar?

A

B

C

D

One carbon atom requires two electrons to achieve the octet electron arrangement.

Satu atom karbon memerlukan dua elektron untuk mencapai susunan elektron oktet.

Each oxygen atom contributes one electron for sharing.

Setiap atom oksigen menyumbang satu elektron untuk dikongsi.

Four double covalent bonds are formed in a carbon dioxide molecule.

Empat ikatan kovalen gandadua terbentuk dalam molekul karbon dioksida.

One carbon atom contributes four electrons to be shared by two oxygen atoms

Satu atom karbon menyumbang empat elektron untuk dikongsi dengan dua atom oksigen.


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DIAGRAM 8RAJAH 8

O C O


KEDAH3. Diagram 12 shows the symbol for the element X.

The letters used are not the actual symbol of the element.

Rajah 12 menunjukkan symbol unsur X.

Huruf yang digunakan bukan symbol sebenar unsur itu.

39

19

DIAGRAM 12

RAJAH 12

Which of the following is true when chlorine gas reacts with X?

Antara berikut,yang manakah benar apabila gas klorin bertindak balas dengan X?

A

B

C

D

One chlorine atom receives one electron from one atom X to form one chloride ion

Satu atom klorin menerima satu electron daripada satu atom X untuk membentuk satu ion klorida

Covalent bond is formed

Ikatan kovalen dibentuk

Chlorine atom donates 7 electrons to one atom X

Atom klorin menderma 7 elektron kepada satu atom X

The molecular formula of the compound formed is XCl2

Formula molekul bagi sebatian yang terbentuk ialah XCl2


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x

C OO


4. P reacts with Q to form ionic compound which formula is PQ3.

P bertindak balas dengan Q untuk membentuk sebatian ionic yang berformula PQ3.

Which of the following electron arrangement of atom P and atom Q are true?Antara susunan elektron bagi atom P dan Q berikut, yang manakah benar?


Susunan elektron

Atom P Atom Q

A 2.3 2.5

B 2.5 2.7

C 2.8 2.8.7

D 2.8.3 2.8.7

5. The diagram shows the electron arrangement of molecule of carbon dioxide CO2

Which of the following statements is true about the molecule?

A The compound has high melting pointB Atom C has four pairs of electrons to shareC The bonding between molecules CO2 is covalent bondingD Each of atom O receives two electrons to form an oxide ion

6. The table shows the proton number of elements P, Q and R.


Element Proton NumberP 11Q 17R 18

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Which of the following is true about the above elements?

A Element P and element R exist as diatomic moleculeB Element P is more electronegative than element QC Element P is more reactive than element R when it reacts with

water.D Element P and element Q react to form a compound which

has high melting point

7. The table shows the proton number of elements P, Q and R.

Which of the following is true about the above elements?

A Element P and element R exist as diatomic moleculeB Element P is more electronegative than element QC Element P is more reactive than element R when it reacts with

water.D Element P and element Q react to form a compound which

has high melting point

8. The electron arrangement of an atom for the element X is 2.4. X reacts with chlorine, Cl2.Which is the correct chemical formula for the compound formed?

A XClB XCl4C XCl2D X4Cl

The table below shows the proton number of atoms elements S and T.

Element Proton numberS 12T 17

9. Which of the following is the correct combinations of chemical formula and chemical

bonding for the compound formed between S and T?

Formula Type of bondA ST2 IonicB S2T IonicC ST2 Covalent


Element Proton NumberP 11Q 17R 18

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D S2T Covalent

10. The diagram 2 shows the electron arrangement of a molecule of water ,H2 ORajah 2 menunjukkan susunan elektron bagi molekul air ,H2O

DIAGRAM 2 RAJAH 2 Which of the following statements is true about the molecule? Antara pernyataan berikut, yang manakah benar tentang molekul itu ?

A

B

C

D

The compound has high melting pointSebatian mempunyai takat lebur yang tinggi

Oxygen atom ,O has four pairs of electrons to shareAtom oksigen, O mempunyai empat pasang elektron untuk di kongsi

The bonding between molecules of water, H2 O is of Van der Waals forcesIkatan antara molekul air, H2 O ialah daya Van der Waals

Each oxygen atom , O receives two electrons to form an oxide ionSetiap atom oksigen, O menerima dua elektron untuk membentuk satu ion oksida.

11. The table 2 shows the electron arrangements of elements R, S, T dan U. Jadual 2 menunjukkan susunan elektron bagi unsur R, S, T dan U

Which of the following pair of elements can form ionic compound? Antara pasangan unsur berikut, yang manakah boleh membentuk sebatian ion? A

B

C

R and SR dan S

S and US dan U

T and UT dan U


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H O H

ElementsUnsur

R S T U

Electron arrangementSusunan elektron

2.4 2.8 2.8.7 2.8.8.2


D R and T R dan T

12. Diagram 10 shows the electron arrangement of a compound formed between element T and element Q. Diagram 10 menunjukkan susunan elektron bagi sebatian yang terbentuk daripada unsur T dan unsur Q.

T+ Q2- T+

What group in the Periodic Table of Elements is element Q located?Apakah kumpulan dalam Jadual Berkala Unsur kedudukan unsur Q?


A 2B 8C 16D 18

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2-+ +

Diagram 10Rajah 10


ACTIVITY 2

1. Figure 8 shows the electron arrangement for atoms P, Q and R.Rajah 8 menunjukkan susunan elektron bagi atom-atom P, Q dan R.

Based on figure 8, answer the following questions:Berdasarkan rajah 8, jawab soalan-soalan berikut:

(a) Atoms P and Q can form chemical bonds with atom R.Atom P dan Q boleh membentuk ikatan kimia dengan atom R.

State the type of chemical bond and explain how the bond is formed between:Nyatakan jenis ikatan kimia dan terangkan bagaimana ikatan terbentuk antara:(i) Atoms P and R(ii) Atoms Q and R

[11 marks]

(b) State one physical property of the compound formed in (b) (i) and the compound formed in (b) (ii). Explain the differences in the physical property stated.Nyatakan satu sifat fizik bagi sebatian yang terbentuk di (b)(i) dan bagi sebatian yang terbentuk di (b)(ii). Terangkan perbezaan bagi sifat fizik yang dinyatakan.

[4 marks]

2. Figure 3 shows the symbol for an atom of element X and an atom of element Y .

FIGURE 3

(a) Based on Figure 3, answer the following questions.(i) Write the formula for the ion formed from an atom of element Y.

.................................................................................................................... [ 1 mark ]


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23

X 11

35

Y 17

PQ R

Atom P Atom Q Atom R


(b ) (i) Draw the electron arrangement of compound formed from the reaction of element X and element Y.

[ 2 marks ](ii) State the type of bond formed between element X and element Y.

..................................................................................................................... [ 1 mark ]

(iii) State one property of the compound formed between element X and element Y.

.................................................................................................................. [ 1 mark ]

3. Diagram 2 shows the symbols of atom for element U, V, W and X. Rajah 2 menunjukkan simbol- simbol atom bagi unsur U, V, W dan X.

DIAGRAM / RAJAH 2

(a) Element V can react with element W to form a compound. Unsur V boleh bertindak balas dengan unsur W membentuk satu sebatian.

(i) Write the chemical formula for the compound.Tuliskan formula kimia bagi sebatian itu.

.................................................................................................................................[1 mark ]

(ii) State one physical property for the compound formed.Nyatakan satu sifat fizikal bagi sebatian yang terbentuk.

……………………………………………………………………………...............[1 mark ]

(b) When element U react with element W, a compound is produced. Apabila unsur U bertindak balas dengan unsur W, satu sebatian terhasil.

(i) State the type of the compound produced.Nyatakan jenis sebatian yang terhasil.

………......................................................................................................................[1 mark ]

(ii) Draw the electron arrangement for the compound in (d) (i).


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Lukiskan susunan elektron bagi sebatian dalam (d) (i).

[2 marks]

ACTIVITY 3

1. Table 1 shows the proton number of atoms of elements X, Y and Z. Jadual di bawah menunjukkan nombor proton bagi unsur-unsur X, Y dan Z.

ElementUnsur

Proton NumberNombor proton

W 1X 3Y 6Z 8

Table 1 Jadual 1

(a) The reaction between elements X and Y form a chemical compound.Explain the formation of this compound.Tindak balas antara unsur –unsur X dan Y membentuk suatu sebatian kimia.

Terangkan pembentukan sebatian ini.[6 marks]

(b) The reaction between elements Z and W form another chemical compound.Tindak balas antara unsur –unsur Z dan W membentuk sebatian kimia lain.

(i) Draw the electron arrangement of the compound formed.Lukiskan susunan elektron bagi sebatian yang terbentuk.

[2 marks]

(ii) Compare two physical properties below for the compounds formed in (b) and (c).


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Melting point Electric conductivity.

Explain the differences in each pysical property.

Bandingkan sifat fizikal di bawah bagi sebatian-sebatian di (b) dan (c) Takat lebur Kekonduksian elektrik

Terang perbezaan dalam setiap sifat fizkal tersebut. [8 marks]

2. Table 9 shows the electron arrangement of atom of element R, Q and Z.Jadual 9 menunjukkan susunan elektron bagi atom unsur R, Q dan Z.

ElementUnsur

Electron arrangementSusunan elektron

RQZ

2.8.22.8.42.8.7

TABLE / JADUAL 9(c ) Based on Table 9, explain in terms of electron arrangement

Berdasarkan Jadual 9, terangkan dari segi susunan elektron

(i) how atoms R and Z form a compound.bagaimana atom R dan Z membentuk sebatian.

(ii) how atoms Q and Z form a compound.bagaimana atom Q dan Z membentuk sebatian.

[8 marks]

(d) Lead(II) bromide, PbBr2 is an ionic compound. Describe an experiment how you would extract lead metal from its compound, PbBr2.In your description , include a labelled diagram and write the half equations of the reaction occurs.Plumbum(II) bromida, PbBr2 ialah sebatian ion. Huraikan satu eksperimenbagaimana anda mengekstrak logam plumbum daripada sebatiannya, PbBr2.Dalam huraian anda, sertakan gambar rajah berlabel dan tuliskan setengah persamaan bagi tindak balas yang berlaku.

END OF CHAPTER 5


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c5 tahap 2 noraidah

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