THE MOLE

Back Titration Method
Redox Titrations - Principles

By the end of the lesson, the learner should be able to:
Understand principle of back titration
Apply back titration to determine composition
Calculate concentrations using back titration data
Determine atomic masses from back titration
Explain principles of redox titrations
Identify color changes in redox reactions
Understand self-indicating nature of some redox reactions
Write ionic equations for redox processes

In groups, learners are guided to:
Experiment: Determine atomic mass of divalent metal in MCO₃. Add excess HCl to carbonate, then titrate excess with NaOH. Calculate moles of acid that reacted with carbonate. Determine metal's atomic mass.
Teacher exposition: Redox titration principles. Demonstrate color changes: MnO₄⁻ (purple) → Mn²⁺ (colorless), Cr₂O₇²⁻ (orange) → Cr³⁺ (green). Discussion: Self-indicating reactions. Write half-equations and overall ionic equations.

Metal carbonate sample, 0.5M HCl, 0M NaOH, Phenolphthalein, Conical flasks
Potassium manganate(VII), Potassium dichromate(VI), Iron(II) solutions, Color change charts

KLB Secondary Chemistry Form 3, Pages 67-70
KLB Secondary Chemistry Form 3, Pages 68-70

THE MOLE

Redox Titrations - KMnO₄ Standardization

By the end of the lesson, the learner should be able to:
Standardize KMnO₄ solution using iron(II) salt
Calculate molarity from redox titration data
Apply 1:5 mole ratio in calculations
Prepare solutions for redox titrations

In groups, learners are guided to:
Experiment: Standardize KMnO₄ using FeSO₄(NH₄)₂SO₄·6H₂O. Dissolve iron salt in boiled, cooled water. Titrate with KMnO₄ until persistent pink color. Calculate molarity using 5:1 mole ratio.

Iron(II) ammonium sulfate, KMnO₄ solution, Dilute H₂SO₄, Pipettes, Burettes

KLB Secondary Chemistry Form 3, Pages 70-72

THE MOLE

Water of Crystallization Determination

By the end of the lesson, the learner should be able to:
Determine water of crystallization in hydrated salts
Use redox titration to find formula of hydrated salt
Calculate value of 'n' in crystallization formulas
Apply analytical data to determine complete formulas

In groups, learners are guided to:
Experiment: Determine 'n' in FeSO₄(NH₄)₂SO₄·nH₂O. Dissolve known mass in acid, titrate with standardized KMnO₄. Calculate moles of iron(II), hence complete formula. Compare theoretical and experimental values.

Hydrated iron(II) salt, Standardized KMnO₄, Dilute H₂SO₄, Analytical balance

KLB Secondary Chemistry Form 3, Pages 72-73

THE MOLE

Atomicity and Molar Gas Volume
Combining Volumes of Gases - Experimental Investigation

By the end of the lesson, the learner should be able to:
Define atomicity of gaseous elements
Classify gases as monoatomic, diatomic, or triatomic
Determine molar gas volume experimentally
Calculate gas densities and molar masses

In groups, learners are guided to:
Experiment: Measure volumes and masses of different gases (O₂, CO₂, Cl₂). Calculate densities and molar masses. Determine volume occupied by one mole. Compare values at different conditions.

Gas syringes (50cm³), Various gases, Analytical balance, Gas supply apparatus
Gas syringes, Dry NH₃ generator, Dry HCl generator, Glass connecting tubes, Clips

KLB Secondary Chemistry Form 3, Pages 73-75

THE MOLE

Gas Laws and Chemical Equations

By the end of the lesson, the learner should be able to:
Apply Avogadro's law to chemical reactions
Use volume ratios to determine chemical equations
Calculate product volumes from reactant volumes
Solve problems involving gas stoichiometry

In groups, learners are guided to:
Worked examples: Use Gay-Lussac's law to determine equations. Calculate volumes of products from given reactant volumes. Apply Avogadro's law to find number of molecules. Practice: Complex gas stoichiometry problems.

Scientific calculators, Gas law charts, Volume ratio examples

KLB Secondary Chemistry Form 3, Pages 77-79

ORGANIC CHEMISTRY I

Introduction to Organic Chemistry and Hydrocarbons
Sources of Alkanes - Natural Gas, Biogas, and Crude Oil

By the end of the lesson, the learner should be able to:
Define organic chemistry and hydrocarbons
Explain why carbon forms many compounds
Classify hydrocarbons into alkanes, alkenes, and alkynes
Identify the bonding in carbon compounds
Identify natural sources of alkanes
Describe composition of natural gas and biogas
Explain crude oil as major source of alkanes
Describe biogas digester and its operation

In groups, learners are guided to:
Teacher exposition: Definition of organic chemistry. Discussion: Unique properties of carbon - tetravalency, catenation, multiple bonding. Q/A: Examples of hydrocarbons in daily life. Introduction to three main groups of hydrocarbons.
Discussion: Natural gas composition (80% methane). Explanation: Biogas formation from organic waste decomposition. Teacher demonstration: Biogas digester model/diagram. Q/A: Environmental benefits of biogas production.

Carbon models, Hydrocarbon structure charts, Molecular model kits
Biogas digester model/diagram, Natural gas composition charts, Organic waste samples

KLB Secondary Chemistry Form 3, Pages 86-87

ORGANIC CHEMISTRY I

Fractional Distillation of Crude Oil

By the end of the lesson, the learner should be able to:
Explain fractional distillation process
Perform fractional distillation of crude oil
Identify different fractions and their uses
Relate boiling points to molecular size

In groups, learners are guided to:
Experiment: Fractional distillation of crude oil using improvised column. Collect fractions at different temperatures (120°C intervals up to 350°C). Test fractions for appearance, flammability, and viscosity. Record observations and relate to molecular size.

Crude oil sample, Boiling tubes, High-temperature thermometer, Sand/porcelain chips, Bunsen burner, Test tubes

KLB Secondary Chemistry Form 3, Pages 87-89

ORGANIC CHEMISTRY I

Cracking of Alkanes - Thermal and Catalytic Methods

By the end of the lesson, the learner should be able to:
Define cracking of alkanes
Distinguish between thermal and catalytic cracking
Write equations for cracking reactions
Explain industrial importance of cracking

In groups, learners are guided to:
Teacher exposition: Definition and purpose of cracking. Discussion: Thermal vs catalytic cracking conditions. Worked examples: Cracking equations producing smaller alkanes, alkenes, and hydrogen. Q/A: Industrial applications and hydrogen production.

Cracking process diagrams, Chemical equation charts, Catalyst samples for demonstration

KLB Secondary Chemistry Form 3, Pages 89-90

ORGANIC CHEMISTRY I

Alkane Series and Homologous Series Concept

By the end of the lesson, the learner should be able to:
Define homologous series using alkanes
Write molecular formulas for first 10 alkanes
Identify characteristics of homologous series
Apply general formula CₙH₂ₙ₊₂ for alkanes

In groups, learners are guided to:
Teacher exposition: Homologous series definition and characteristics. Table completion: Names, molecular formulas, and structures of first 10 alkanes. Discussion: General formula application. Pattern recognition: Gradual change in physical properties.

Alkane series chart, Molecular formula worksheets, Periodic table

KLB Secondary Chemistry Form 3, Pages 90-92

ORGANIC CHEMISTRY I

Nomenclature of Alkanes - Straight Chain and Branched

By the end of the lesson, the learner should be able to:
Name straight-chain alkanes using IUPAC rules
Identify parent chains in branched alkanes
Name branched alkanes with substituent groups
Apply systematic naming rules correctly

In groups, learners are guided to:
Teacher demonstration: Step-by-step naming of branched alkanes. Rules application: Longest chain identification, numbering from nearest branch, substituent naming. Practice exercises: Various branched alkane structures. Group work: Name complex branched alkanes.

Structural formula charts, IUPAC naming rules poster, Molecular model kits

KLB Secondary Chemistry Form 3, Pages 90-92

ORGANIC CHEMISTRY I

Isomerism in Alkanes - Structural Isomers
Laboratory Preparation of Methane

By the end of the lesson, the learner should be able to:
Define isomerism in alkanes
Draw structural isomers of butane and pentane
Distinguish between chain and positional isomerism
Predict number of isomers for given alkanes
Describe laboratory preparation of methane
Perform methane preparation experiment safely
Test physical and chemical properties of methane
Write equation for methane preparation

In groups, learners are guided to:
Teacher exposition: Isomerism definition and types. Practical exercise: Draw all isomers of butane and pentane. Discussion: Physical property differences between isomers. Model building: Use molecular models to show isomeric structures.
Experiment: Heat mixture of sodium ethanoate and soda lime. Collect methane gas over water. Tests: Color, smell, combustion, reaction with bromine in dark. Record observations in table format. Safety precautions during gas collection.

Molecular model kits, Isomerism charts, Structural formula worksheets
Sodium ethanoate, Soda lime, Round-bottomed flask, Gas collection apparatus, Bromine water, Wooden splints

KLB Secondary Chemistry Form 3, Pages 92-94
KLB Secondary Chemistry Form 3, Pages 94-96

ORGANIC CHEMISTRY I

Laboratory Preparation of Ethane
Physical Properties of Alkanes

By the end of the lesson, the learner should be able to:
Prepare ethane using sodium propanoate and soda lime
Compare preparation methods of methane and ethane
Test properties of ethane gas
Write general equation for alkane preparation

In groups, learners are guided to:
Experiment: Prepare ethane from sodium propanoate and soda lime. Compare with methane preparation method. Carry out similar tests as for methane. Discussion: General pattern for alkane preparation from sodium alkanoates.

Sodium propanoate, Soda lime, Gas collection apparatus, Testing materials
Physical properties data tables, Graph paper, Calculators, Solubility demonstration materials

KLB Secondary Chemistry Form 3, Pages 94-96

ORGANIC CHEMISTRY I

Chemical Properties of Alkanes - Combustion and Substitution

By the end of the lesson, the learner should be able to:
Write equations for complete and incomplete combustion
Explain substitution reactions with halogens
Describe conditions for halogenation reactions
Name halogenated alkane products

In groups, learners are guided to:
Worked examples: Combustion equations for various alkanes. Teacher demonstration: Methane + bromine in sunlight (or simulation). Discussion: Free radical mechanism in substitution. Practice: Write equations for chlorination of methane.

Molecular models, Halogenation reaction charts, Chemical equation worksheets

KLB Secondary Chemistry Form 3, Pages 97-98

ORGANIC CHEMISTRY I

Uses of Alkanes in Industry and Daily Life

By the end of the lesson, the learner should be able to:
List major uses of different alkanes
Explain industrial applications of alkanes
Describe environmental considerations
Evaluate economic importance of alkanes

In groups, learners are guided to:
Discussion: Uses of gaseous alkanes as fuels. Teacher exposition: Industrial applications - carbon black, methanol production, hydrogen source. Q/A: Environmental impact and cleaner fuel initiatives. Assignment: Research local uses of alkane products.

Industrial application charts, Product samples, Environmental impact materials

KLB Secondary Chemistry Form 3, Pages 98-100

ORGANIC CHEMISTRY I

Introduction to Alkenes and Functional Groups

By the end of the lesson, the learner should be able to:
Define alkenes and unsaturation
Identify the C=C functional group
Write general formula for alkenes (CₙH₂ₙ)
Compare alkenes with alkanes

In groups, learners are guided to:
Teacher exposition: Alkenes definition and unsaturation concept. Introduction: C=C double bond as functional group. Table study: First 6 members of alkene series. Comparison: Alkenes vs alkanes - formulas and structures.

Alkene series charts, Molecular models showing double bonds, Functional group posters

KLB Secondary Chemistry Form 3, Pages 100-101

ORGANIC CHEMISTRY I

Nomenclature of Alkenes
Isomerism in Alkenes - Branching and Positional

By the end of the lesson, the learner should be able to:
Apply IUPAC rules for naming alkenes
Number carbon chains to give lowest numbers to double bonds
Name branched alkenes with substituents
Distinguish position isomers of alkenes
Draw structural isomers of alkenes
Distinguish between branching and positional isomerism
Identify geometric isomers in alkenes
Predict isomer numbers for given molecular formulas

In groups, learners are guided to:
Teacher demonstration: Step-by-step naming of alkenes. Rules application: Longest chain with double bond, numbering from end nearest double bond. Practice exercises: Name various alkene structures. Group work: Complex branched alkenes with substituents.
Practical exercise: Draw all isomers of butene and pentene. Teacher exposition: Branching vs positional isomerism in alkenes. Model building: Use molecular models for isomer visualization. Discussion: Geometric isomerism introduction (basic level).

IUPAC naming charts for alkenes, Structural formula worksheets, Molecular model kits
Molecular model kits, Isomerism worksheets, Geometric isomer models

KLB Secondary Chemistry Form 3, Pages 101-102
KLB Secondary Chemistry Form 3, Pages 102

ORGANIC CHEMISTRY I

Laboratory Preparation of Ethene

By the end of the lesson, the learner should be able to:
Prepare ethene by dehydration of ethanol
Describe role of concentrated sulfuric acid
Set up apparatus safely for ethene preparation
Test physical and chemical properties of ethene

In groups, learners are guided to:
Experiment: Dehydration of ethanol using concentrated H₂SO₄ at 170°C. Use sand bath for controlled heating. Pass gas through NaOH to remove impurities. Tests: Bromine water, acidified KMnO₄, combustion. Safety precautions with concentrated acid.

Ethanol, Concentrated H₂SO₄, Round-bottomed flask, Sand bath, Gas collection apparatus, Testing solutions

KLB Secondary Chemistry Form 3, Pages 102-104

ORGANIC CHEMISTRY I

Alternative Preparation of Ethene and Physical Properties

By the end of the lesson, the learner should be able to:
Describe catalytic dehydration using aluminum oxide
Compare different preparation methods
List physical properties of ethene
Explain trends in alkene physical properties

In groups, learners are guided to:
Demonstration: Alternative method using Al₂O₃ catalyst. Comparison: Acid vs catalytic dehydration methods. Data analysis: Physical properties of alkenes table. Discussion: Property trends with increasing molecular size.

Aluminum oxide catalyst, Glass wool, Alternative apparatus setup, Physical properties charts

KLB Secondary Chemistry Form 3, Pages 102-104

ORGANIC CHEMISTRY I

Chemical Properties of Alkenes - Addition Reactions

By the end of the lesson, the learner should be able to:
Explain addition reactions due to C=C double bond
Write equations for halogenation of alkenes
Describe hydrogenation and hydrohalogenation
Explain addition mechanism

In groups, learners are guided to:
Teacher exposition: Addition reactions definition and mechanism. Worked examples: Ethene + Cl₂, Br₂, HBr, H₂. Discussion: Markovnikov's rule for unsymmetrical addition. Practice: Various addition reaction equations.

Addition reaction charts, Mechanism diagrams, Chemical equation worksheets

KLB Secondary Chemistry Form 3, Pages 105-107

ORGANIC CHEMISTRY I

Oxidation Reactions of Alkenes and Polymerization

By the end of the lesson, the learner should be able to:
Describe oxidation by KMnO₄ and K₂Cr₂O₇
Explain polymerization of ethene
Define monomers and polymers
Write equations for polymer formation

In groups, learners are guided to:
Demonstration: Decolorization of KMnO₄ by alkenes. Teacher exposition: Polymerization process and polymer formation. Examples: Ethene → polyethene formation. Discussion: Industrial importance of polymerization. Practice: Write polymerization equations.

Oxidizing agents for demonstration, Polymer samples, Polymerization charts, Monomer-polymer models

KLB Secondary Chemistry Form 3, Pages 107-108

ORGANIC CHEMISTRY I

Tests for Alkenes and Uses
Introduction to Alkynes and Triple Bond
Nomenclature and Isomerism in Alkynes

By the end of the lesson, the learner should be able to:
Perform chemical tests to identify alkenes
Use bromine water and KMnO₄ as test reagents
List industrial and domestic uses of alkenes
Explain importance in plastic manufacture
Apply IUPAC naming rules for alkynes
Name branched alkynes with substituents
Draw structural isomers of alkynes
Identify branching and positional isomerism

In groups, learners are guided to:
Practical session: Test known alkenes with bromine water and acidified KMnO₄. Observe rapid decolorization compared to alkanes. Discussion: Uses in plastics, ethanol production, fruit ripening, detergents. Assignment: Research alkene applications.
Teacher demonstration: Systematic naming of alkynes using -yne suffix. Practice exercises: Name various alkyne structures. Drawing exercise: Isomers of pentyne and hexyne. Group work: Complex branched alkynes with multiple substituents.

Test alkenes, Bromine water, Acidified KMnO₄, Plastic samples, Uses reference charts
Alkyne series charts, Triple bond molecular models, Unsaturation comparison charts
IUPAC naming rules for alkynes, Structural formula worksheets, Molecular model kits

KLB Secondary Chemistry Form 3, Pages 108-109
KLB Secondary Chemistry Form 3, Pages 110-111

ORGANIC CHEMISTRY I

Laboratory Preparation of Ethyne

By the end of the lesson, the learner should be able to:
Prepare ethyne from calcium carbide and water
Set up gas collection apparatus safely
Test physical and chemical properties of ethyne
Write equation for ethyne preparation

In groups, learners are guided to:
Experiment: Calcium carbide + water reaction. Use sand layer for heat absorption. Collect ethyne over water. Tests: Color, smell, combustion, bromine water, acidified KMnO₄. Safety: Dry apparatus, controlled water addition.

Calcium carbide, Sand, Flat-bottomed flask, Dropping funnel, Gas collection apparatus, Testing solutions

KLB Secondary Chemistry Form 3, Pages 111-112

ORGANIC CHEMISTRY I

Physical and Chemical Properties of Alkynes

By the end of the lesson, the learner should be able to:
Describe physical properties of alkynes
Compare alkyne properties with alkenes and alkanes
Write combustion equations for alkynes
Explain addition reactions of alkynes

In groups, learners are guided to:
Data analysis: Physical properties of alkynes table. Comparison: Alkynes vs alkenes vs alkanes properties. Worked examples: Combustion reactions of ethyne. Teacher exposition: Two-step addition reactions due to triple bond.

Physical properties charts, Comparison tables, Combustion equation examples

KLB Secondary Chemistry Form 3, Pages 112-113

ORGANIC CHEMISTRY I

Addition Reactions of Alkynes and Chemical Tests

By the end of the lesson, the learner should be able to:
Write equations for halogenation of alkynes
Describe hydrogenation and hydrohalogenation
Compare reaction rates: alkynes vs alkenes
Perform chemical tests for alkynes

In groups, learners are guided to:
Worked examples: Two-step addition reactions of ethyne with Br₂, Cl₂, H₂. Discussion: Faster reaction rates in alkynes compared to alkenes. Practical session: Test alkynes with oxidizing agents. Comparison: Rate of decolorization vs alkenes.

Addition reaction charts, Chemical equation worksheets, Test solutions, Stopwatch for rate comparison

KLB Secondary Chemistry Form 3, Pages 113-115

ORGANIC CHEMISTRY I

Uses of Alkynes and Industrial Applications

By the end of the lesson, the learner should be able to:
List industrial uses of alkynes
Explain oxy-acetylene welding applications
Describe use in synthetic fiber production
Evaluate importance as chemical starting materials

In groups, learners are guided to:
Discussion: Industrial applications of alkynes in adhesives, plastics, synthetic fibers. Teacher demonstration: Oxy-acetylene flame principles (or video). Q/A: Starting materials for chemical synthesis. Assignment: Research local industrial uses.

Industrial application charts, Welding equipment demonstration/video, Synthetic fiber samples

KLB Secondary Chemistry Form 3, Pages 115-116