THE MOLE

Relative Mass - Introduction and Experimental Investigation
Avogadro's Constant and the Mole Concept
Interconversion of Mass and Moles for Elements

By the end of the lesson, the learner should be able to:
Define relative mass using practical examples
Compare masses of different objects using a reference standard
Explain the concept of relative atomic mass
Identify carbon-12 as the reference standard
Apply the formula: moles = mass/molar mass
Calculate mass from given moles of elements
Convert between moles and number of atoms
Solve numerical problems involving moles and mass

Experiment: Weighing different sized nails using beam balance. Use smallest nail as reference standard. Q/A: Discuss everyday examples of relative measurements. Teacher exposition: Introduction of carbon-12 scale and IUPAC recommendations. Calculate relative masses from experimental data.
Worked examples: Mass-mole conversions using triangle method. Supervised practice: Calculate moles in given masses of common elements. Problem solving: Convert moles to atoms using Avogadro's number. Assignment: Practice problems on interconversion.

Different sized nails ( 5-15cm), Beam balance, Fruits of different masses, Reference charts
Beam balance, Various sized nails, Scientific calculators, Avogadro's constant charts
Scientific calculators, Periodic table, Worked example charts, Formula triangles

KLB Secondary Chemistry Form 3, Pages 25-27
KLB Secondary Chemistry Form 3, Pages 30-32

THE MOLE

Molecules and Moles - Diatomic Elements

By the end of the lesson, the learner should be able to:
Distinguish between atoms and molecules
Define relative molecular mass
Calculate moles of molecules from given mass
Determine number of atoms in molecular compounds

Discussion: Elements existing as molecules (O₂, H₂, N₂, Cl₂). Teacher exposition: Difference between atomic and molecular mass. Worked examples: Calculate moles of molecular elements. Problem solving: Number of atoms in molecular compounds.

Molecular models, Charts showing diatomic elements, Scientific calculators

KLB Secondary Chemistry Form 3, Pages 29-30

THE MOLE

Empirical Formula - Experimental Determination
Empirical Formula - Reduction Method

By the end of the lesson, the learner should be able to:
Define empirical formula
Determine empirical formula from experimental data
Calculate mole ratios from mass data
Express results as simplest whole number ratios

Experiment: Burning magnesium in air to form magnesium oxide. Measure masses before and after reaction. Calculate moles of Mg and O from mass data. Determine mole ratio and empirical formula. Safety precautions during heating.

Crucible and lid, Magnesium ribbon, Bunsen burner, Beam balance, Tongs, Safety equipment
Combustion tube, Porcelain boat, Copper(II) oxide, Laboratory gas, Beam balance, Bunsen burner

KLB Secondary Chemistry Form 3, Pages 32-35

THE MOLE

Empirical Formula - Percentage Composition Method

By the end of the lesson, the learner should be able to:
Calculate empirical formula from percentage composition
Convert percentages to moles
Determine simplest whole number ratios
Apply method to various compounds

Worked examples: Calculate empirical formula from percentage data. Method: percentage → mass → moles → ratio. Practice problems: Various compounds with different compositions. Discussion: When to multiply ratios to get whole numbers.

Scientific calculators, Percentage composition charts, Worked example displays

KLB Secondary Chemistry Form 3, Pages 37-38

THE MOLE

Molecular Formula - Determination from Empirical Formula
Molecular Formula - Combustion Analysis
Concentration and Molarity of Solutions

By the end of the lesson, the learner should be able to:
Define molecular formula
Relate molecular formula to empirical formula
Calculate molecular formula using molecular mass
Apply the relationship (empirical formula)ₙ = molecular formula
Define concentration and molarity of solutions
Calculate molarity from mass and volume data
Convert between different concentration units
Apply molarity calculations to various solutions

Teacher exposition: Difference between empirical and molecular formulas. Worked examples: Calculate molecular formula from empirical formula and molecular mass. Formula: n = molecular mass/empirical formula mass. Practice problems with various organic compounds.
Teacher exposition: Definition of molarity (moles/dm³). Worked examples: Calculate molarity from mass of solute and volume. Convert between g/dm³ and mol/dm³. Practice problems: Various salt solutions and their molarities.

Scientific calculators, Molecular mass charts, Worked example displays
Scientific calculators, Combustion analysis charts, Molecular models of hydrocarbons
Scientific calculators, Molarity charts, Various salt samples for demonstration

KLB Secondary Chemistry Form 3, Pages 38-40
KLB Secondary Chemistry Form 3, Pages 41-43

THE MOLE

Preparation of Molar Solutions
Dilution of Solutions

By the end of the lesson, the learner should be able to:
Describe procedure for preparing molar solutions
Use volumetric flasks correctly
Calculate masses needed for specific molarities
Prepare standard solutions accurately

Experiment: Prepare 1M, 0.5M, and 0.25M NaOH solutions in different volumes. Use volumetric flasks of 1000cm³, 500cm³, and 250cm³. Calculate required masses. Demonstrate proper dissolution and dilution techniques.

Volumetric flasks (250, 500, 1000cm³), Sodium hydroxide pellets, Beam balance, Wash bottles, Beakers
Volumetric flasks, Hydrochloric acid (2M), Measuring cylinders, Pipettes, Safety equipment

KLB Secondary Chemistry Form 3, Pages 43-46

THE MOLE

Stoichiometry - Experimental Determination of Equations

By the end of the lesson, the learner should be able to:
Determine chemical equations from experimental data
Calculate mole ratios from mass measurements
Write balanced chemical equations
Apply stoichiometry to displacement reactions

Experiment: Iron displacement of copper from CuSO₄ solution. Measure masses of iron used and copper displaced. Calculate mole ratios. Derive balanced chemical equation. Discuss spectator ions.

Iron filings, Copper(II) sulphate solution, Beam balance, Beakers, Filter equipment

KLB Secondary Chemistry Form 3, Pages 50-53

THE MOLE

Stoichiometry - Precipitation Reactions

By the end of the lesson, the learner should be able to:
Investigate stoichiometry of precipitation reactions
Determine mole ratios from volume measurements
Write ionic equations for precipitation
Analyze limiting and excess reagents

Experiment: Pb(NO₃)₂ + KI precipitation reaction. Use different volumes to determine stoichiometry. Measure precipitate heights. Plot graphs to find reaction ratios. Identify limiting reagents.

Test tubes, Lead(II) nitrate solution, Potassium iodide solution, Burettes, Ethanol, Rulers

KLB Secondary Chemistry Form 3, Pages 53-56

THE MOLE

Stoichiometry - Gas Evolution Reactions
Volumetric Analysis - Introduction and Apparatus
Titration - Acid-Base Neutralization

By the end of the lesson, the learner should be able to:
Determine stoichiometry of gas-producing reactions
Collect and measure gas volumes
Calculate mole ratios involving gases
Write equations for acid-carbonate reactions
Perform acid-base titrations accurately
Use indicators to determine end points
Record titration data properly
Calculate average titres from multiple readings

Experiment: HCl + Na₂CO₃ reaction. Collect CO₂ gas in plastic bag. Measure gas mass and calculate moles. Determine mole ratios of reactants and products. Write balanced equation.
Experiment: Titrate 25cm³ of 0.1M NaOH with 0.1M HCl using phenolphthalein. Repeat three times for consistency. Record data in tabular form. Calculate average titre. Discuss accuracy and precision.

Conical flask, Thistle funnel, Plastic bags, Rubber bands, Sodium carbonate, HCl solution
Pipettes (10, 20, 25cm³), Burettes (50cm³), Pipette fillers, Conical flasks, Various solutions
Burettes, Pipettes, 0.1M NaOH, 0.1M HCl, Phenolphthalein indicator, Conical flasks

KLB Secondary Chemistry Form 3, Pages 56-58
KLB Secondary Chemistry Form 3, Pages 59-62

THE MOLE

Titration - Diprotic Acids
Standardization of Solutions

By the end of the lesson, the learner should be able to:
Investigate titrations involving diprotic acids
Determine basicity of acids from titration data
Compare volumes needed for mono- and diprotic acids
Write equations for diprotic acid reactions

Experiment: Titrate 25cm³ of 0.1M NaOH with 0.1M H₂SO₄. Compare volume used with previous HCl titration. Calculate mole ratios. Explain concept of basicity. Introduce dibasic and tribasic acids.

Burettes, Pipettes, 0.1M H₂SO₄, 0.1M NaOH, Phenolphthalein, Basicity reference chart
Anhydrous Na₂CO₃, Approximately 0.1M HCl, Methyl orange, Volumetric flasks, Analytical balance

KLB Secondary Chemistry Form 3, Pages 62-65

THE MOLE

Back Titration Method

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

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.

Metal carbonate sample, 0.5M HCl, 0M NaOH, Phenolphthalein, Conical flasks

KLB Secondary Chemistry Form 3, Pages 67-70

THE MOLE

Redox Titrations - Principles
Redox Titrations - KMnO₄ Standardization

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

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.

Potassium manganate(VII), Potassium dichromate(VI), Iron(II) solutions, Color change charts
Iron(II) ammonium sulfate, KMnO₄ solution, Dilute H₂SO₄, Pipettes, Burettes

KLB Secondary Chemistry Form 3, Pages 68-70

THE MOLE

Water of Crystallization Determination
Atomicity and Molar Gas Volume

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
Define atomicity of gaseous elements
Classify gases as monoatomic, diatomic, or triatomic
Determine molar gas volume experimentally
Calculate gas densities and molar masses

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.
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.

Hydrated iron(II) salt, Standardized KMnO₄, Dilute H₂SO₄, Analytical balance
Gas syringes (50cm³), Various gases, Analytical balance, Gas supply apparatus

KLB Secondary Chemistry Form 3, Pages 72-73
KLB Secondary Chemistry Form 3, Pages 73-75

THE MOLE

Combining Volumes of Gases - Experimental Investigation
Gas Laws and Chemical Equations

By the end of the lesson, the learner should be able to:
Investigate Gay-Lussac's law experimentally
Measure combining volumes of reacting gases
Determine simple whole number ratios
Write equations from volume relationships

Experiment: React NH₃ and HCl gases in measured volumes. Observe formation of NH₄Cl solid. Measure residual gas volumes. Determine combining ratios. Apply to other gas reactions.

Gas syringes, Dry NH₃ generator, Dry HCl generator, Glass connecting tubes, Clips
Scientific calculators, Gas law charts, Volume ratio examples

KLB Secondary Chemistry Form 3, Pages 75-77

ORGANIC CHEMISTRY I

Introduction to Organic Chemistry and Hydrocarbons

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

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.

Carbon models, Hydrocarbon structure charts, Molecular model kits

KLB Secondary Chemistry Form 3, Pages 86-87

ORGANIC CHEMISTRY I

Sources of Alkanes - Natural Gas, Biogas, and Crude Oil
Fractional Distillation of Crude Oil

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

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.

Biogas digester model/diagram, Natural gas composition charts, Organic waste samples
Crude oil sample, Boiling tubes, High-temperature thermometer, Sand/porcelain chips, Bunsen burner, Test tubes

KLB Secondary Chemistry Form 3, Pages 86-87

ORGANIC CHEMISTRY I

Cracking of Alkanes - Thermal and Catalytic Methods
Alkane Series and Homologous Series Concept

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
Define homologous series using alkanes
Write molecular formulas for first 10 alkanes
Identify characteristics of homologous series
Apply general formula CₙH₂ₙ₊₂ for alkanes

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.
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.

Cracking process diagrams, Chemical equation charts, Catalyst samples for demonstration
Alkane series chart, Molecular formula worksheets, Periodic table

KLB Secondary Chemistry Form 3, Pages 89-90
KLB Secondary Chemistry Form 3, Pages 90-92

ORGANIC CHEMISTRY I

Nomenclature of Alkanes - Straight Chain and Branched
Isomerism in Alkanes - Structural Isomers

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

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
Molecular model kits, Isomerism charts, Structural formula worksheets

KLB Secondary Chemistry Form 3, Pages 90-92

ORGANIC CHEMISTRY I

Laboratory Preparation of Methane

By the end of the lesson, the learner should be able to:
Describe laboratory preparation of methane
Perform methane preparation experiment safely
Test physical and chemical properties of methane
Write equation for methane preparation

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.

Sodium ethanoate, Soda lime, Round-bottomed flask, Gas collection apparatus, Bromine water, Wooden splints

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

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
Uses of Alkanes in Industry and Daily Life
Introduction to Alkenes and Functional Groups

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
List major uses of different alkanes
Explain industrial applications of alkanes
Describe environmental considerations
Evaluate economic importance of alkanes

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.
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.

Molecular models, Halogenation reaction charts, Chemical equation worksheets
Industrial application charts, Product samples, Environmental impact materials
Alkene series charts, Molecular models showing double bonds, Functional group posters

KLB Secondary Chemistry Form 3, Pages 97-98
KLB Secondary Chemistry Form 3, Pages 98-100

ORGANIC CHEMISTRY I

Nomenclature of Alkenes

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

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.

IUPAC naming charts for alkenes, Structural formula worksheets, Molecular model kits

KLB Secondary Chemistry Form 3, Pages 101-102

ORGANIC CHEMISTRY I

Isomerism in Alkenes - Branching and Positional

By the end of the lesson, the learner should be able to:
Draw structural isomers of alkenes
Distinguish between branching and positional isomerism
Identify geometric isomers in alkenes
Predict isomer numbers for given molecular formulas

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).

Molecular model kits, Isomerism worksheets, Geometric isomer models

KLB Secondary Chemistry Form 3, Pages 102

ORGANIC CHEMISTRY I

Laboratory Preparation of Ethene
Alternative Preparation of Ethene and Physical Properties

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

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
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
Oxidation Reactions of Alkenes and Polymerization
Tests for Alkenes and Uses

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
Describe oxidation by KMnO₄ and K₂Cr₂O₇
Explain polymerization of ethene
Define monomers and polymers
Write equations for polymer formation

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.
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.

Addition reaction charts, Mechanism diagrams, Chemical equation worksheets
Oxidizing agents for demonstration, Polymer samples, Polymerization charts, Monomer-polymer models
Test alkenes, Bromine water, Acidified KMnO₄, Plastic samples, Uses reference charts

KLB Secondary Chemistry Form 3, Pages 105-107
KLB Secondary Chemistry Form 3, Pages 107-108

ORGANIC CHEMISTRY I

Introduction to Alkynes and Triple Bond

By the end of the lesson, the learner should be able to:
Define alkynes and triple bond structure
Write general formula for alkynes (CₙH₂ₙ₋₂)
Identify first members of alkyne series
Compare degree of unsaturation in hydrocarbons

Teacher exposition: Alkynes definition and C≡C triple bond. Table study: First 6 members of alkyne series with structures. Discussion: Degrees of unsaturation - alkanes vs alkenes vs alkynes. Model demonstration: Triple bond representation.

Alkyne series charts, Triple bond molecular models, Unsaturation comparison charts

KLB Secondary Chemistry Form 3, Pages 109-110

ORGANIC CHEMISTRY I

Nomenclature and Isomerism in Alkynes
Laboratory Preparation of Ethyne

By the end of the lesson, the learner should be able to:
Apply IUPAC naming rules for alkynes
Name branched alkynes with substituents
Draw structural isomers of alkynes
Identify branching and positional isomerism

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.

IUPAC naming rules for alkynes, Structural formula worksheets, Molecular model kits
Calcium carbide, Sand, Flat-bottomed flask, Dropping funnel, Gas collection apparatus, Testing solutions

KLB Secondary Chemistry Form 3, Pages 110-111

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

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
ORGANIC CHEMISTRY I
CHLORINE AND ITS COMPOUNDS
CHLORINE AND ITS COMPOUNDS

Addition Reactions of Alkynes and Chemical Tests
Uses of Alkynes and Industrial Applications
Introduction and Preparation of Chlorine
Physical Properties of Chlorine

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
List industrial uses of alkynes
Explain oxy-acetylene welding applications
Describe use in synthetic fiber production
Evaluate importance as chemical starting materials

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.
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.

Addition reaction charts, Chemical equation worksheets, Test solutions, Stopwatch for rate comparison
Industrial application charts, Welding equipment demonstration/video, Synthetic fiber samples
Manganese(IV) oxide, Concentrated HCl, Gas collection apparatus, Water, Concentrated H2SO4, Blue litmus paper, Gas jars
Preserved chlorine gas, Water trough, Gas jars, Observation tables, Safety equipment

KLB Secondary Chemistry Form 3, Pages 113-115
KLB Secondary Chemistry Form 3, Pages 115-116

CHLORINE AND ITS COMPOUNDS

Chemical Properties of Chlorine - Reaction with Water
Chemical Properties of Chlorine - Reaction with Metals
Chemical Properties of Chlorine - Reaction with Non-metals

By the end of the lesson, the learner should be able to:
Investigate the reaction of chlorine with water. Explain the formation of chlorine water. Test the acidic nature of chlorine water. Demonstrate the bleaching action of chlorine.

Practical work: Experiment 6.3 - Bubbling chlorine through water. Testing with litmus papers (dry vs moist). Testing with colored flower petals. Formation of green-yellow chlorine water. Writing equations: Cl2 + H2O → HCl + HOCl. Discussion: Formation of hypochlorous acid and hydrochloric acid.

Chlorine gas, Distilled water, Blue and red litmus papers, Colored flower petals, Gas jars, Boiling tubes
Magnesium ribbon, Iron wire, Chlorine gas, Deflagrating spoon, Combustion tube, Anhydrous CaCl2, Gas jars
Red phosphorus, Hydrogen gas, Chlorine gas, Deflagrating spoon, Gas jars, Bunsen burner, Safety equipment

KLB Secondary Chemistry Form 4, Pages 197-199

CHLORINE AND ITS COMPOUNDS

Oxidising Properties of Chlorine
Reaction of Chlorine with Alkali Solutions
Oxidising Properties - Displacement Reactions

By the end of the lesson, the learner should be able to:
Investigate chlorine as an oxidizing agent. Test reactions with reducing agents. Write ionic equations for redox reactions. Identify color changes in oxidation reactions.

Practical work: Experiment 6.6 - Bubbling chlorine through sodium sulphite solution, testing with barium nitrate and lead nitrate. Reactions with hydrogen sulphide and ammonia. Recording observations in Table 6. Color changes and precipitate formation. Writing ionic equations: SO3²⁻ + Cl2 + H2O → SO4²⁻ + 2Cl⁻ + 2H⁺.

Sodium sulphite solution, Barium nitrate, Lead nitrate, Hydrogen sulphide gas, Aqueous ammonia, Chlorine gas, Test tubes
Sodium hydroxide solutions (dilute cold, concentrated hot), Chlorine gas, Beakers, Bunsen burner, Thermometer
Potassium bromide solution, Potassium iodide solution, Chlorine gas, Test tubes, Observation charts

KLB Secondary Chemistry Form 4, Pages 201-202

CHLORINE AND ITS COMPOUNDS

Test for Chloride Ions
Uses of Chlorine and its Compounds

By the end of the lesson, the learner should be able to:
Carry out confirmatory tests for chloride ions. Distinguish between different chloride tests. Practice qualitative analysis techniques. Write equations for chloride ion tests.

Practical work: Experiment 6.9 - Testing sodium chloride with concentrated H2SO4, testing with lead(II) nitrate solution. Recording observations in Table 6. Tests: White fumes with H2SO4 + ammonia test, white precipitate with Pb(NO3)2 that dissolves on warming. Writing equations: NaCl + H2SO4 → NaHSO4 + HCl, Pb²⁺ + 2Cl⁻ → PbCl

Sodium chloride, Concentrated H2SO4, Lead(II) nitrate solution, Aqueous ammonia, Glass rod, Test tubes, Bunsen burner
Charts showing industrial uses, Samples of bleaching agents, PVC materials, Photographs of water treatment plants, Industrial application diagrams

KLB Secondary Chemistry Form 4, Pages 204-205

CHLORINE AND ITS COMPOUNDS

Hydrogen Chloride - Laboratory Preparation
Chemical Properties of Hydrogen Chloride

By the end of the lesson, the learner should be able to:
Describe laboratory preparation of hydrogen chloride gas. Set up apparatus for HCl preparation. Investigate physical properties of HCl gas. Explain the method of collection used.
Prepare aqueous hydrogen chloride (hydrochloric acid). Investigate acid properties of HCl solution. Test reactions with metals, bases, and carbonates. Compare HCl in water vs organic solvents.

Practical work: Experiment 6.10 - Preparation using rock salt (NaCl) + concentrated H2SO Setup apparatus as in Figure 6.3(b). Testing physical properties and recording in Table 6.6. Tests: Solubility (fountain experiment), reaction with ammonia, effect on litmus. Collection by downward delivery due to density. Writing equation: NaCl + H2SO4 → NaHSO4 + HCl.
Practical work: Experiment 6.11 - Preparation of aqueous HCl using apparatus in Figure 6. Testing with metals (Zn, Fe, Mg, Cu), NaOH, carbonates, lead nitrate. Recording observations in Table 6.7. Testing HCl in methylbenzene - no acid properties. Discussion: Ionization in water vs molecular existence in organic solvents. Writing equations for acid reactions.

Rock salt (NaCl), Concentrated H2SO4, Gas collection apparatus, Ammonia solution, Litmus papers, Water trough, Gas jars
Distilled water, Filter funnel, Metals (Zn, Fe, Mg, Cu), NaOH solution, Carbonates, Lead nitrate, Methylbenzene, Indicators

KLB Secondary Chemistry Form 4, Pages 207-208
KLB Secondary Chemistry Form 4, Pages 208-211

CHLORINE AND ITS COMPOUNDS

Large-scale Manufacture of Hydrochloric Acid
Uses of Hydrochloric Acid

By the end of the lesson, the learner should be able to:
Describe industrial production of hydrochloric acid. Identify raw materials and conditions used. Explain the controlled combustion process. Draw flow diagrams of the industrial process.

Study of Figure 6.4 - Large-scale manufacture setup. Discussion: Raw materials (H2 from electrolysis/cracking, Cl2 from electrolysis). Controlled combustion: H2 + Cl2 → 2HCl in jet burner. Dissolving HCl gas in water over glass beads. Safety: Explosive nature of H2/Cl2 mixture, use of excess chlorine. Industrial considerations: 35% concentration, transport in rubber-lined steel tanks.

Flow diagrams, Industrial photographs, Glass beads samples, Charts showing electrolysis processes, Safety equipment models
Samples of rusted and cleaned metals, Photographic materials, pH control charts, Industrial application videos, Water treatment diagrams

KLB Secondary Chemistry Form 4, Pages 211-212

CHLORINE AND ITS COMPOUNDS

Environmental Pollution by Chlorine Compounds and Summary

By the end of the lesson, the learner should be able to:
Explain environmental effects of chlorine compounds. Describe the impact of CFCs on ozone layer. Discuss pollution by chlorine-containing pesticides. Summarize key concepts of chlorine chemistry.

Discussion: Environmental impacts - chlorine gas forming acid rain, CFCs (life span CCl3F = 75 years, CCl2F2 = 110 years) breaking down ozone layer. DDT as persistent pesticide, PVC as non-biodegradable plastic. NEMA role in environmental protection, Stockholm Convention on DDT. Control measures and alternatives. Revision: Key reactions, properties, uses, and environmental considerations. Summary of halogen chemistry concepts.

Environmental pollution charts, Ozone layer diagrams, DDT restriction documents, PVC waste samples, NEMA guidelines, Summary charts of reactions

KLB Secondary Chemistry Form 4, Pages 213-215