STRUCTURE & BONDING

Chemical bonds. Ionic bond.

By the end of the lesson, the learner should be able to:
Describe role of valence electrons in determining chemical bonding.


Explain formation of ionic bonding.

Q/A: Review valence electrons of atoms of elements in groups I, II, III, VII and VIII.
Q/A: Review group I and group VII elements.
Discuss formation of ionic bond.

text book

K.L.B. BOOK IIP54




PP 57-58

STRUCTURE & BONDING

Ionic bond representation.
Grant ionic structures.
Physical properties of ionic compounds.
Covalent bond.
Co-ordinate bond.
Molecular structure.

By the end of the lesson, the learner should be able to:
Use dot and cross diagrams to represent ionic bonding.
Explain the formation of covalent bond
Use dot and cross diagrams to represent covalent bond.

Drawing diagrams of ionic bonds.
Exposition: Shared pair of electrons in a hydrogen molecule, H2O, NH3, Cl2, and CO2.
Drawing of dot-and-cross diagrams of covalent bonds.

Chart- dot and cross diagrams.
Models for bonding.
Giant sodium chloride model.
text book

K.L.B. BOOK II P. 58
K.L.B. BOOK II PP 60-63

STRUCTURE & BONDING

Trend in physical properties of molecular structures.
Giant atomic structure in diamond.
Giant atomic structure in graphite.

By the end of the lesson, the learner should be able to:
To describe van- der -waals forces.
To explain the trend in physical properties of molecular structures.

Discuss comparative physical properties of substances. exhibiting molecular structure.
Explain variation in the physical properties.

Sugar, naphthalene, iodine rhombic sulphur.
Diagrams in textbooks.

K.L.B. BOOK IIP 65

STRUCTURE & BONDING

Metallic bond. Uses of some metals.

By the end of the lesson, the learner should be able to:
To describe mutual electronic forces between electrons and nuclei.
To describe metallic bond.
To compare physical properties of metals.
To state uses of some metals.

Discussion:
Detailed analysis of comparative physical properties of metals and their uses.



Probing questions & brief explanations.

text book

K.L.B. BOOK IIP 70

PROPERTIES AND TRENDS ACROSS PERIOD THREE

Physical properties of elements in periods.
Physical properties of elements in period 3.
Chemical properties of elements in period 3.
Chemical properties of elements in the third period.
Oxides of period 3 elements.
Chlorides of period 3 elements.

By the end of the lesson, the learner should be able to:




To compare electrical conductivity of elements in period 3
To compare reactions of elements in period 3 with water

Group experiments- Construct electrical circuits incorporating a magnesium ribbon, then aluminum foil, then sulphur in turns.
The brightness of the bulb is noted in each case.
Discuss the observations in terms of delocalised electrons.

Q/A: Review reaction of sodium, Mg, chlorine, with water.
Infer that sodium is most reactive metal; non-metals do not react with water.

The periodic table.

K.L.B. BOOK IIP. 76
K.L.B. BOOK II PP. 80-81

SALTS

Types of salts.
Solubility of salts in water.

By the end of the lesson, the learner should be able to:
Define a salt.
Describe various types of salts and give several examples in each case.

Descriptive approach. Teacher exposes new concepts.

text book
Sulphates, chlorides, nitrates, carbonates of various metals.

K.L.B. BOOK II P. 91

SALTS

Solubility of bases in water.

By the end of the lesson, the learner should be able to:
To test solubility of various bases in water.
To carry out litmus test on the resulting solutions.

Class experiments- Dissolve salts in 5cc of water.
Record the solubility in a table,
Carry out litmus tests.
Discuss the results.

Oxides, hydroxides, of various metals, litmus papers.

K.L.B. BOOK IIPP. 94-95

SALTS

Methods of preparing various salts.
Direct synthesis of a salts.
Ionic equations.
Effects of heat on carbonates.
Effects of heat on nitrates.

By the end of the lesson, the learner should be able to:
To describe various methods of preparing some salts.
To identify spectator ions in double decomposition reactions.
To write ionic equations correctly.

Experimental and descriptive treatments of preparation of salts e.g. ZnSO4, CuSO4, NaCl and Pb(NO3)2.


Q/A: Ions present in given reactants.
Deduce the products of double decomposition reactions.
Give examples of equations.
Supervised practice.

CuO, H2SO4, HCl, NaOH, PbCO3, dil HNO3.
Iron,
Sulphur
PbNO3, MgSO4 solutions.
Various carbonates.
Common metal nitrates.

K.L.B. BOOK II pp96

SALTS

Effects of heat on sulphates.
Hygroscopy, Deliquescence and Efflorescence.
Uses of salts.

By the end of the lesson, the learner should be able to:
To state effects of heat on sulphates.
To predict products results from heating metal sulphates.

Group experiments- To investigate effects of heat on various sulphates.
Observe various colour changes before, during and after heating.
Write equations for the reactions.

Common sulphates.

K.L.B. BOOK II P. 113

EFFECTS OF AN ELECTRIC CURRENT ON SUBSTANCES.

Molten electrolytes.
Electrolysis.

By the end of the lesson, the learner should be able to:
To test for electrical conductivities molten electrolytes.

Group experiments- to identify electrolytes in molten form.
Explain the difference in molten electrolytes.

Molten candle wax
Sugar
Sulphur
Lead oxide.

K.L.B. BOOK IIPP. 120-121

EFFECTS OF AN ELECTRIC CURRENT ON SUBSTANCES.

Aqueous electrolytes. Electrodes.
Reaction on electrodes.
Binary electrolyte.
Application of electrolysis.
Electroplating.

By the end of the lesson, the learner should be able to:
To define an electrolyte
To test for electrical conductivities of electrodes.
To define a binary electrolyte.
To state the products of a binary electrolyte.

To investigate chemical effect of an electric current.
Classify the solutions as electrolyte or non -electrolytes.
Discuss the electrical properties of the solutions.
Completing a table of electrolysis of binary electrolytes.

Graphite electrodes
Battery
Various aqueous solutions switch bulb.
Various aqueous solutions switch.
text book
Silver nitrate
Iron nail
Complete circuit battery.

K.L.B. BOOK II PP.122-123
K.L.B. BOOK II P.127

CARBON AND SOME OF ITS COMPOUNDS.

Allotropy.
Physical and chemical properties of diamond, graphite and amorphous carbon
Burning carbon and oxygen.

By the end of the lesson, the learner should be able to:
Define allotropes and allotropy.
Identify allotropes of carbon.
Represent diamond and graphite diagrammatically.

Teacher exposes new terms.
Review covalent bond.
Discuss boding in diamond and graphite.

text book
Charcoal, graphite.
Carbon, limewater, tube, limewater stand& Bunsen burner.

K.L.B. BOOK II PP. 131-133

CARBON AND SOME OF ITS COMPOUNDS.

Reduction properties of carbon.
Reaction of carbon with acids. Preparation of CO2.
Properties of CO2.

By the end of the lesson, the learner should be able to:
Describe reduction properties of carbon.
Show reduction properties of carbon.

Teacher demonstration ? Burn strongly a mixture of carbon and CuO on a bottle top.
Observe colour changes and give underlying explanation

CuO, pounded charcoal, Bunsen burner& bottle top
Conc. HNO3, limewater.
Lime water,
Magnesium ribbon,
Universal indicator,
lit candle.

K.L.B. BOOK II P.126

CARBON AND SOME OF ITS COMPOUNDS.

Chemical equations for reactions involving CO2.
Uses of CO2.
Carbon monoxide lab preparation.
Chemical properties of carbon monoxide.
Carbonates and hydrogen carbonates.

By the end of the lesson, the learner should be able to:
Write balanced CO2.
To describe preparation of carbon monoxide in the lab

Give examples of reactions. Write corresponding balanced chemical equations.
Teacher demonstration: preparation of carbon monoxide in the lab.
Make observations.

text book

K.L.B. BOOK II PP.139-140
K.L.B. BOOK II PP. 142-143

CARBON AND SOME OF ITS COMPOUNDS.

Heating carbonates and hydrogen carbonates.
Extraction of sodium carbonate from trona.
Solvay process of preparing sodium carbonate.
Importance of carbon in nature. & its effects on the environment.

By the end of the lesson, the learner should be able to:
To write equations for reaction of carbonates and hydrogen carbonates on heating.

Discuss the above observations.
Write corresponding balanced equations.

text book
text book, chart

K.L.B. BOOK II PP.150-151