THE MOLE

Relative Mass - Introduction and Experimental Investigation
Avogadro's Constant and the Mole Concept

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

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.

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

KLB Secondary Chemistry Form 3, Pages 25-27

THE MOLE

Interconversion of Mass and Moles for Elements

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

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.

Scientific calculators, Periodic table, Worked example charts, Formula triangles

KLB Secondary Chemistry Form 3, Pages 30-32

THE MOLE

Molecules and Moles - Diatomic Elements
Empirical Formula - Experimental Determination
Empirical Formula - Reduction Method

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
Determine empirical formula using reduction reactions
Calculate empirical formula from reduction data
Apply reduction method to copper oxides
Analyze experimental errors and sources

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.
Experiment: Reduction of copper(II) oxide using laboratory gas. Measure masses before and after reduction. Calculate moles of copper and oxygen. Determine empirical formula from mole ratios. Discuss experimental precautions.

Molecular models, Charts showing diatomic elements, Scientific calculators
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 29-30
KLB Secondary Chemistry Form 3, Pages 35-37

THE MOLE

Empirical Formula - Percentage Composition Method
Molecular Formula - Determination from Empirical Formula

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
Scientific calculators, Molecular mass charts, Worked example displays

KLB Secondary Chemistry Form 3, Pages 37-38

THE MOLE

Molecular Formula - Combustion Analysis

By the end of the lesson, the learner should be able to:
Determine molecular formula from combustion data
Calculate moles of products in combustion
Relate product moles to reactant composition
Apply combustion analysis to hydrocarbons

Worked examples: Hydrocarbon combustion producing CO₂ and H₂O. Calculate moles of C and H from product masses. Determine empirical formula, then molecular formula. Practice: Various combustion analysis problems.

Scientific calculators, Combustion analysis charts, Molecular models of hydrocarbons

KLB Secondary Chemistry Form 3, Pages 40-41

THE MOLE

Concentration and Molarity of Solutions

By the end of the lesson, the learner should be able to:
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: 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, Molarity charts, Various salt samples for demonstration

KLB Secondary Chemistry Form 3, Pages 41-43

THE MOLE

Preparation of Molar Solutions
Dilution of Solutions
Stoichiometry - Experimental Determination of Equations

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
Determine chemical equations from experimental data
Calculate mole ratios from mass measurements
Write balanced chemical equations
Apply stoichiometry to displacement reactions

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.
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.

Volumetric flasks (250, 500, 1000cm³), Sodium hydroxide pellets, Beam balance, Wash bottles, Beakers
Volumetric flasks, Hydrochloric acid (2M), Measuring cylinders, Pipettes, Safety equipment
Iron filings, Copper(II) sulphate solution, Beam balance, Beakers, Filter equipment

KLB Secondary Chemistry Form 3, Pages 43-46
KLB Secondary Chemistry Form 3, Pages 50-53

THE MOLE

Stoichiometry - Precipitation Reactions
Stoichiometry - Gas Evolution 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
Conical flask, Thistle funnel, Plastic bags, Rubber bands, Sodium carbonate, HCl solution

KLB Secondary Chemistry Form 3, Pages 53-56

THE MOLE

Volumetric Analysis - Introduction and Apparatus

By the end of the lesson, the learner should be able to:
Define volumetric analysis and titration
Identify and use titration apparatus correctly
Explain functions of pipettes and burettes
Demonstrate proper reading techniques

Practical session: Familiarization with pipettes and burettes. Practice filling and reading burettes accurately. Learn proper meniscus reading. Use pipette fillers safely. Rinse apparatus with appropriate solutions.

Pipettes (10, 20, 25cm³), Burettes (50cm³), Pipette fillers, Conical flasks, Various solutions

KLB Secondary Chemistry Form 3, Pages 58-59

THE MOLE

Titration - Acid-Base Neutralization
Titration - Diprotic Acids

By the end of the lesson, the learner should be able to:
Perform acid-base titrations accurately
Use indicators to determine end points
Record titration data properly
Calculate average titres from multiple readings

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.

Burettes, Pipettes, 0.1M NaOH, 0.1M HCl, Phenolphthalein indicator, Conical flasks
Burettes, Pipettes, 0.1M H₂SO₄, 0.1M NaOH, Phenolphthalein, Basicity reference chart

KLB Secondary Chemistry Form 3, Pages 59-62

THE MOLE

Standardization of Solutions
Back Titration Method
Redox Titrations - Principles

By the end of the lesson, the learner should be able to:
Define standardization process
Standardize HCl using Na₂CO₃ as primary standard
Calculate accurate concentrations from titration data
Understand importance of primary standards
Understand principle of back titration
Apply back titration to determine composition
Calculate concentrations using back titration data
Determine atomic masses from back titration

Experiment: Prepare approximately 0.1M HCl and standardize using accurately weighed Na₂CO₃. Use methyl orange indicator. Calculate exact molarity from titration results. Discuss primary standard requirements.
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.

Anhydrous Na₂CO₃, Approximately 0.1M HCl, Methyl orange, Volumetric flasks, Analytical balance
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 65-67
KLB Secondary Chemistry Form 3, Pages 67-70

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

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
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

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
Gas syringes (50cm³), Various gases, Analytical balance, Gas supply apparatus

KLB Secondary Chemistry Form 3, Pages 72-73

THE MOLE

Combining Volumes of Gases - Experimental Investigation

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

KLB Secondary Chemistry Form 3, Pages 75-77

THE MOLE
NITROGEN AND ITS COMPOUNDS

Gas Laws and Chemical Equations
Uses of Nitric(V) Acid and Introduction to Nitrates
Action of Heat on Nitrates - Decomposition Patterns

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
List major industrial uses of nitric acid
Explain importance in fertilizer manufacture
Describe use in explosives and dyes
Introduce nitrate salts and their preparation

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.
Discussion: Uses - fertilizer production (NH₄NO₃), explosives (TNT), dyes, drugs, metal purification, etching. Introduction to nitrates as salts of nitric acid. Methods of preparation: acid + base, acid + carbonate, acid + metal. Examples of common nitrates.

Scientific calculators, Gas law charts, Volume ratio examples
Industrial use charts, Nitrate salt samples, Preparation method diagrams, Safety data sheets
Various nitrate salts, Test tubes, Bunsen burner, Gas collection apparatus, Glowing splints, Observation recording sheets

KLB Secondary Chemistry Form 3, Pages 77-79
KLB Secondary Chemistry Form 3, Pages 151

NITROGEN AND ITS COMPOUNDS

Test for Nitrates - Brown Ring Test

By the end of the lesson, the learner should be able to:
Perform brown ring test for nitrates
Explain mechanism of complex formation
Use alternative copper test method
Apply tests to unknown samples

Experiments: (a) Brown ring test - add FeSO₄ solution to nitrate, then carefully add concentrated H₂SO₄. Observe brown ring formation. (b) Alternative test - warm nitrate with H₂SO₄ and copper turnings. Observe brown fumes. Test unknown samples.

Sodium nitrate, Fresh FeSO₄ solution, Concentrated H₂SO₄, Copper turnings, Test tubes, Unknown nitrate samples

KLB Secondary Chemistry Form 3, Pages 153-154

NITROGEN AND ITS COMPOUNDS

Environmental Pollution by Nitrogen Compounds
Pollution Control and Environmental Solutions

By the end of the lesson, the learner should be able to:
Explain sources of nitrogen pollution
Describe formation of acid rain
Discuss effects on environment and health
Evaluate pollution control measures

Teacher exposition: NOₓ from vehicles, HNO₃ formation in atmosphere, acid rain effects. Discussion: Chlorosis in plants, building corrosion, soil leaching, smog formation, health effects. Control measures: Catalytic converters, emission controls, proper fertilizer use.

Environmental pollution charts, Acid rain effect photos, Vehicle emission diagrams, Control measure illustrations
Case studies, Pollution control technology information, Group activity worksheets, Local environmental data

KLB Secondary Chemistry Form 3, Pages 154-157

NITROGEN AND ITS COMPOUNDS

Comprehensive Problem Solving - Nitrogen Chemistry

By the end of the lesson, the learner should be able to:
Solve complex problems involving nitrogen compounds
Apply knowledge to industrial processes
Calculate yields and percentages in reactions
Analyze experimental data and results

Problem-solving session: Mixed calculations involving nitrogen preparation, ammonia synthesis, nitric acid concentration, fertilizer analysis. Industrial application problems. Data analysis from experiments. Integration of all nitrogen chemistry concepts.

Scientific calculators, Comprehensive problem sets, Industrial data sheets, Experimental result tables

KLB Secondary Chemistry Form 3, Pages 119-157

NITROGEN AND ITS COMPOUNDS

Laboratory Practical Assessment - Nitrogen Compounds
Industrial Applications and Economic Importance
Chapter Review and Integration

By the end of the lesson, the learner should be able to:
Demonstrate practical skills in nitrogen chemistry
Perform qualitative analysis of nitrogen compounds
Apply safety procedures correctly
Interpret experimental observations accurately
Synthesize all nitrogen chemistry concepts
Compare preparation methods for nitrogen compounds
Relate structure to properties and reactivity
Connect laboratory and industrial processes

Practical examination: Identify unknown nitrogen compounds using chemical tests. Prepare specified nitrogen compounds. Demonstrate proper laboratory techniques. Safety assessment. Written report on observations and conclusions.
Comprehensive review: Concept mapping of all nitrogen compounds and their relationships. Comparison tables: Preparation methods, properties, uses. Flow chart: Nitrogen cycle in industry and environment. Integration exercises connecting all topics.

Unknown nitrogen compounds, All laboratory chemicals and apparatus used in chapter, Safety equipment, Assessment rubrics
Economic data sheets, Industry case studies, Agricultural statistics, Cost-benefit analysis templates
Concept mapping materials, Comparison charts, Flow diagram templates, Integration worksheets

KLB Secondary Chemistry Form 3, Pages 119-157