CHEMISTRY FORM 4 KSSM CHAPTER 5 : CHEMICAL BONDS (Uses of ionic compound and covalent compound in daily life) 1. INDUSTRIAL SECTOR 2. AGRICULTURAL SECTOR 3. MEDICAL SECTOR 4. DOMESTIC USE

1. CHAPTER 5
CHEMICAL BONDS

2. 5.7.1 Compare the properties of ionic and
covalent compounds through experiment.
 List properties of ionic compounds.
 List properties of covalent compounds.
 Explain differences in the electrical conductivity of ionic and covalent
compounds.
 Describe differences in the melting and boiling points of ionic and covalent
compounds.
 Compare and contrast the solubility of ionic and covalent compound.
5.7 Properties of Ionic Compounds and
Covalent Compounds

3. Ionic Compound Covalent Compound
Exists as solids at room temperature. May exists as solids, liquids or gases.
Have high melting and boiling points Have low melting and boiling points.
Conduct electricity in aqueous solution or molten state. Do not conduct electricity.
Usually dissolve in water. Usually do not dissolve in water.
Usually do not dissolve in organic solvent. Usually dissolve in organic solvent.
Properties of Ionic and Covalent Compounds
1. Aqueous state : The substance is dissolved in water.
2. Molten state : The substance becomes ‘liquid form’ by heating
3. Organic solvents : Carbon-based substances capable of dissolving one or more other substances. Example :
Benzen, Acetone, Acetic Acid, Carbon Tetrachloride, Chloroform

4. EXPERIMENT 5.1
Aim : To study the difference in properties between ionic compounds and covalent
compounds.
Problem statement : What are the difference in properties between ionic compounds
and covalent compounds?
Materials : Solid lead(Il) bromide, PbBr2 , naphthalene, C10H8 , magnesium chloride,
MgCl2 , cyclohexane, C6H12 and distilled water
Apparatus : Test tubes, spatula, evaporating dish, Bunsen burner, pipe clay triangle,
wire gauze, beaker, 10 cm3 measuring cylinder, tripod stand, battery, switch, light bulb
and carbon electrodes

5. A. Electrical conductivity of compounds
Hypothesis : Ionic compounds can conduct electricity in molten state but not in
solid state while covalent compounds cannot conduct electricity in both states.
Variables :
a) Manipulated : Type of compound
b) Responding : Electrical conductivity
c) Fixed : Carbon electrode
Safety Precautions :
1. Naphthalene, C10H8, is a flammable substance
2. Bromine gas, Br2 produced during the heating of lead(II) bromide, PbBr2 is
poisonous

6. Procedure :
1. Put lead(II) bromide, PbBr2 powder into the crucible until half full.
2. Set up the apparatus as shown in Figure 5.21.
3. Switch on the circuit and observe whether the bulb light up.
4. Switch off and heat the lead(II) bromide, PbBr2 powder until all solids have melted.
5. Switch on once again and observe whether the bulb lights up.
6. Repeat steps 1 to 5 using naphthalene, C10H8 powder.
7. Record your observation on the condition of the bulb in Table 5.1.

7. Results :
Compound Physical state Condition of the bulb
Lead(II)bromide, PbBr2
Solid The bulb did not glow.
Molten The bulb glow brightly
Naphthalene, C10H8
Solid The bulb did not glow.
Molten The bulb did not glow.

8. B. Solubility of compounds in water and in organic solvent.
Hypothesis : Ionic compound dissolves in water but not in organic solvent whereas
covalent compound dissolves in organic solvent but not in water.
Variables :
a) Manipulated : Type of compound
b) Responding : Solubility of compound in water and in organic solvent
c) Fixed : Mass of compound, Volume water and organic solvent used.

9. Procedure :
1. Put half spatula of magnesium chloride, MgCl2 powder into the test tube.
2. Add 5 cm3 of distilled water into test tube and shake gently.
3. Observe the solubility of magnesium chloride, MgCl2 in water.
4. Repeat steps 1 to 3 using cyclohexane, C6H12 as the solvent.
5. Repeat steps 1 to 4 and substitute magnesium chloride, MgCl2 with naphthalene, C10H8.
6. Record your observations on the solubility of compounds in Table 5.2.

10. Results :
Compound Solubility in distilled water Solubility in cyclohexane, C6H12
Magnesium chloride, MgCl2
White solid dissolves in water. White solid did not dissolve in
cyclohexane, C6H12
Naphthalene, C10H8
White solid did not dissolve in
water.
White solid dissolves in
cyclohexane, C6H12

11. C. Melting point and boiling point of compound
Hypothesis : Ionic compound has high boiling point and melting point whereas
covalent compound has low melting point and boiling point.
Variables :
a) Manipulated : Type of compound
b) Responding : Melting point and boiling point of compound
c) Fixed : Mass of compound used

12. Procedure :
1. Put half spatula of magnesium chloride, MgCl2 powder and naphthalene, C10H8 into separate
test tube.
2. Heat both test tube in water bath as shown in Figure 5.23. for 10 to 15 minutes.
3. Observe and record the change in physical states and make inference of both substances in
Table 5.3.

13. Results :
Compound Observation Inference
Magnesium chloride,
MgCl2
White solid remained
after 15 minutes.
High melting point
Naphthalene, C10H8 White solid melts. Low melting point

14. Conclusion :
Discussion :
1. What type of compound is lead(II) bromide, PbBr2, magnesium chloride, MgCl2 and
naphthalene, C10H8 ?
2. Predict the electrical conductivity, solubility, melting point and boiling point of sodium
chloride, NaCl.
Lead(II) bromide, PbBr2, and magnesium chloride, MgCl2 are ionic compounds whereas
napthalene, C10H8 is a covalent compound.
Sodium chloride, NaCl is an compound. Therefore sodium chloride can conduct electricity in
molten and aqueous form, dissolve in water but cannot dissolve in organic solvent and has has
high melting point and boiling point
Hypothesis is accepted.
1. Ionic compounds have high melting and boiling points, whereas covalent compounds have low
melting and boiling point.
2. Ionic compounds are usually soluble in water but insoluble in organic solvents. Covalent
compounds are usually insoluble in water but soluble in organic solvents.
3. Ionic compounds can conduct electricity in the molten state but cannot conduct electricity in the
solid state. Covalent compounds cannot conduct electricity in the solid and molten state.

15. Electrical
conductivity

16. Electric conductivity
•Based on Experiment 5.1, ionic compounds and covalent
compounds have different electrical conductivity.
•Ionic compounds cannot conduct electricity in the solid state but
can conduct electricity in the molten state and aqueous solution.
•Covalent compounds cannot conduct electricity in all states

20. Solubility
in water and
organic solvent

21. Solubility in Water and Organic Solvent
•Most ionic compounds are soluble in water but are not soluble in
organic solvents.
• Most covalent compounds are not soluble in water but are soluble
in organic solvents.

22. Solubility in Water and Organic Solvent
•When dissolved in water, water molecules help to overcome
electrostatic attraction force between ions and break down the
lattice structure of the solid compound. As a result, ions can move
freely in water.

23. 5.7.2 Explain with examples the uses of ionic
and covalent compounds in daily life
 State the uses of covalent compounds as solvents
5.7 Ionic and covalent compounds

24. Uses of Ionic Compounds and Covalent Compounds in Our Daily Lives
Most ionic compounds and covalent compounds used in our daily lives are in
the industrial sector, agriculture, medicine and domestic use.

25. Uses of Ionic Compounds and Covalent Compounds in Our Daily Lives
Most ionic compounds and covalent compounds used in our daily lives are in
the industrial sector, agriculture, medicine and domestic use.

26. Uses of Ionic Compounds and Covalent Compounds in Our Daily Lives
Most ionic compounds and covalent compounds used in our daily lives are in
the industrial sector, agriculture, medicine and domestic use.

27. Uses of Ionic Compounds and Covalent Compounds in Our Daily Lives
Most ionic compounds and covalent compounds used in our daily lives are in
the industrial sector, agriculture, medicine and domestic use.