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
Molecules and Moles - Diatomic Elements
Empirical Formula - Experimental Determination

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
Distinguish between atoms and molecules
Define relative molecular mass
Calculate moles of molecules from given mass
Determine number of atoms in molecular compounds

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.
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.

Scientific calculators, Periodic table, Worked example charts, Formula triangles
Molecular models, Charts showing diatomic elements, Scientific calculators
Crucible and lid, Magnesium ribbon, Bunsen burner, Beam balance, Tongs, Safety equipment

KLB Secondary Chemistry Form 3, Pages 30-32
KLB Secondary Chemistry Form 3, Pages 29-30

THE MOLE

Empirical Formula - Reduction Method

By the end of the lesson, the learner should be able to:
Determine empirical formula using reduction reactions
Calculate empirical formula from reduction data
Apply reduction method to copper oxides
Analyze experimental errors and sources

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.

Combustion tube, Porcelain boat, Copper(II) oxide, Laboratory gas, Beam balance, Bunsen burner

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
Preparation of Molar Solutions
Dilution 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
Define dilution process
Apply dilution formula M₁V₁ = M₂V₂
Calculate concentrations after dilution
Prepare dilute solutions from concentrated ones

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.
Experiment: Dilute 25cm³ of 2M HCl to different final volumes (250cm³ and 500cm³). Calculate resulting concentrations. Worked examples using dilution formula. Safety precautions when diluting acids.

Scientific calculators, Molarity charts, Various salt samples for demonstration
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 41-43
KLB Secondary Chemistry Form 3, Pages 46-50

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
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
Standardization of Solutions

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
Define standardization process
Standardize HCl using Na₂CO₃ as primary standard
Calculate accurate concentrations from titration data
Understand importance of primary standards

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.
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.

Burettes, Pipettes, 0.1M NaOH, 0.1M HCl, Phenolphthalein indicator, Conical flasks
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 59-62
KLB Secondary Chemistry Form 3, Pages 65-67

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

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
Potassium manganate(VII), Potassium dichromate(VI), Iron(II) solutions, Color change charts

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
THE MOLE
NITROGEN AND ITS COMPOUNDS

Combining Volumes of Gases - Experimental Investigation
Gas Laws and Chemical Equations
Introduction to Nitrogen - Properties and Occurrence

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
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

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.
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.

Gas syringes, Dry NH₃ generator, Dry HCl generator, Glass connecting tubes, Clips
Scientific calculators, Gas law charts, Volume ratio examples
Periodic table charts, Atmospheric composition diagrams, Molecular models showing N≡N triple bond

KLB Secondary Chemistry Form 3, Pages 75-77
KLB Secondary Chemistry Form 3, Pages 77-79

NITROGEN AND ITS COMPOUNDS

Isolation of Nitrogen from Air - Industrial and Laboratory Methods

By the end of the lesson, the learner should be able to:
Describe isolation of nitrogen from air
Explain fractional distillation of liquid air
Set up apparatus for laboratory isolation
Identify impurities removed during isolation

Experiment: Laboratory isolation using aspirator. Pass air through KOH solution to remove CO₂, then over heated copper to remove oxygen. Teacher demonstration: Fractional distillation principles. Flow chart study: Industrial nitrogen production steps.

Aspirator, KOH solution, Copper turnings, Heating apparatus, Fractional distillation flow chart

KLB Secondary Chemistry Form 3, Pages 119-121

NITROGEN AND ITS COMPOUNDS

Laboratory Preparation of Nitrogen Gas
Properties and Uses of Nitrogen Gas

By the end of the lesson, the learner should be able to:
Prepare nitrogen gas from ammonium compounds
Use sodium nitrite and ammonium chloride method
Test physical and chemical properties of nitrogen
Write equations for nitrogen preparation

Experiment: Mix sodium nitrite (7g) and ammonium chloride ( 5g) with water. Heat gently and collect gas over water. Tests: Color, smell, burning splint, litmus paper, lime water, burning Mg and S. Safety precautions during heating.

Sodium nitrite, Ammonium chloride, Round-bottomed flask, Gas collection apparatus, Test reagents, Deflagrating spoon
Property summary charts, Uses of nitrogen displays, Industrial application diagrams

KLB Secondary Chemistry Form 3, Pages 121-123

NITROGEN AND ITS COMPOUNDS

Nitrogen(I) Oxide - Preparation and Properties

By the end of the lesson, the learner should be able to:
Prepare nitrogen(I) oxide from ammonium nitrate
Test physical and chemical properties
Explain decomposition and oxidizing properties
Describe uses of nitrogen(I) oxide

Experiment: Heat ammonium nitrate carefully in test tube. Collect gas over warm water. Tests: Color, smell, glowing splint test, reaction with heated copper and sulfur. Safety: Stop heating while some solid remains to avoid explosion.

Ammonium nitrate, Test tubes, Gas collection apparatus, Copper turnings, Sulfur, Glowing splints

KLB Secondary Chemistry Form 3, Pages 123-125

NITROGEN AND ITS COMPOUNDS

Nitrogen(II) Oxide - Preparation and Properties
Nitrogen(IV) Oxide - Preparation and Properties
Comparison of Nitrogen Oxides and Environmental Effects

By the end of the lesson, the learner should be able to:
Prepare nitrogen(II) oxide from copper and dilute nitric acid
Observe colorless gas and brown fumes formation
Test reactions with air and iron(II) sulfate
Explain oxidation in air to NO₂
Compare preparation methods of nitrogen oxides
Distinguish between different nitrogen oxides
Explain formation in vehicle engines
Describe environmental pollution effects

Experiment: Add dilute HNO₃ to copper turnings. Observe brown fumes formation then disappearance. Tests: Effect on litmus, burning splint, FeSO₄ complex formation. Discussion: NO oxidation to NO₂ in air.
Comparative study: Properties table of N₂O, NO, NO₂. Discussion: Formation in internal combustion engines. Environmental effects: Acid rain formation, smog, health problems. Worked examples: Distinguishing tests for each oxide.

Copper turnings, Dilute nitric acid, Gas collection apparatus, Iron(II) sulfate solution, Test reagents
Copper turnings, Concentrated nitric acid, Lead(II) nitrate, Gas collection apparatus, U-tube with ice, Testing materials
Comparison charts, Environmental impact diagrams, Vehicle emission illustrations

KLB Secondary Chemistry Form 3, Pages 125-127
KLB Secondary Chemistry Form 3, Pages 123-131

NITROGEN AND ITS COMPOUNDS

Laboratory Preparation of Ammonia
Preparation of Aqueous Ammonia and Solubility

By the end of the lesson, the learner should be able to:
Prepare ammonia from ammonium salts and alkalis
Set up apparatus with proper gas collection
Test characteristic properties of ammonia
Explain displacement reaction principle

Experiment: Heat mixture of calcium hydroxide and ammonium chloride. Collect gas by upward delivery using calcium oxide as drying agent. Tests: Color, smell, combustion, HCl fumes test, litmus paper. Safety: Slanted flask position.

Calcium hydroxide, Ammonium chloride, Round-bottomed flask, Calcium oxide, HCl solution, Glass rod, Litmus paper
Ammonia generation apparatus, Funnel, Universal indicator, Fountain apparatus, pH meter/paper

KLB Secondary Chemistry Form 3, Pages 131-134

NITROGEN AND ITS COMPOUNDS

Reactions of Aqueous Ammonia with Metal Ions

By the end of the lesson, the learner should be able to:
Test reactions of aqueous ammonia with various metal ions
Observe precipitate formation and dissolution
Explain complex ion formation
Use reactions for metal ion identification

Experiment: Add aqueous ammonia dropwise to solutions of Ca²⁺, Mg²⁺, Al³⁺, Zn²⁺, Fe²⁺, Fe³⁺, Pb²⁺, Cu²⁺. Record observations with few drops vs excess ammonia. Identify complex ion formation with Zn²⁺ and Cu²⁺.

Various metal salt solutions, Aqueous ammonia, Test tubes, Droppers, Observation recording tables

KLB Secondary Chemistry Form 3, Pages 136-138

NITROGEN AND ITS COMPOUNDS

Chemical Properties of Ammonia - Reactions with Acids and Combustion

By the end of the lesson, the learner should be able to:
Test neutralization reactions with acids
Investigate combustion of ammonia
Examine catalytic oxidation with platinum
Study reducing properties with metal oxides

Experiments: (a) Neutralize H₂SO₄, HCl, HNO₃ with aqueous ammonia using indicators. (b) Attempt combustion in air and oxygen. (c) Catalytic oxidation with heated platinum wire. (d) Reduction of CuO by ammonia. Record all observations.

Various dilute acids, Methyl orange, Oxygen supply, Platinum wire, Copper(II) oxide, Combustion apparatus, U-tube for collection

KLB Secondary Chemistry Form 3, Pages 138-140

NITROGEN AND ITS COMPOUNDS

Industrial Manufacture of Ammonia - The Haber Process
Uses of Ammonia and Introduction to Nitrogenous Fertilizers
Nitrogenous Fertilizers - Types and Calculations

By the end of the lesson, the learner should be able to:
Describe raw materials and their sources
Explain optimum conditions for ammonia synthesis
Draw flow diagram of Haber process
Explain economic considerations and catalyst use
Calculate percentage nitrogen in various fertilizers
Compare fertilizer effectiveness
Prepare simple nitrogenous fertilizers
Discuss environmental considerations

Teacher exposition: N₂ from air, H₂ from natural gas/cracking. Process conditions: 500°C, 200 atm, iron catalyst. Flow diagram study: Purification, compression, catalytic chamber, separation, recycling. Economic factors: Compromise between yield and rate.
Worked examples: Calculate % N in (NH₄)₂SO₄, NH₄NO₃, (NH₄)₃PO₄, CO(NH₂)₂, CAN. Comparison: Urea has highest nitrogen content. Practical: Prepare ammonium sulfate from ammonia and sulfuric acid. Environmental impact discussion.

Haber process flow charts, Industrial diagrams, Catalyst samples, Economic analysis sheets
Fertilizer samples, Percentage calculation worksheets, Use application charts, Calculator
Various fertilizer formulas, Scientific calculators, Laboratory preparation materials, Environmental impact data

KLB Secondary Chemistry Form 3, Pages 140-141
KLB Secondary Chemistry Form 3, Pages 141-144

NITROGEN AND ITS COMPOUNDS

Laboratory Preparation of Nitric(V) Acid
Industrial Manufacture of Nitric(V) Acid

By the end of the lesson, the learner should be able to:
Prepare nitric acid from nitrate and concentrated sulfuric acid
Set up all-glass apparatus safely
Explain brown fumes and yellow color
Purify nitric acid by air bubbling

Experiment: Heat mixture of KNO₃ and concentrated H₂SO₄ in all-glass apparatus. Collect yellow nitric acid. Explain brown fumes (NO₂) and yellow color. Bubble air through to remove dissolved NO₂. Safety: Gentle heating, fume cupboard.

Potassium nitrate, Concentrated sulfuric acid, All-glass apparatus, Condenser, Retort stand, Safety equipment
Industrial process flow charts, Catalyst samples, Process condition charts, Efficiency calculation sheets

KLB Secondary Chemistry Form 3, Pages 144-145

NITROGEN AND ITS COMPOUNDS

Reactions of Dilute Nitric(V) Acid with Metals

By the end of the lesson, the learner should be able to:
Test reactions with various metals
Explain absence of hydrogen gas production
Observe formation of nitrogen oxides
Write equations for metal-acid reactions

Experiment: Add dilute HNO₃ to Mg, Zn, Cu. Test gases produced with burning splint. Observe that no H₂ is produced (except with Mg in very dilute acid). Explain oxidation of any H₂ formed to water. Record observations and write equations.

Various metals (Mg, Zn, Cu), Dilute nitric acid, Test tubes, Gas testing apparatus, Burning splints

KLB Secondary Chemistry Form 3, Pages 147-150

NITROGEN AND ITS COMPOUNDS

Reactions of Dilute Nitric(V) Acid with Carbonates and Hydroxides
Reactions of Concentrated Nitric(V) Acid - Oxidizing Properties

By the end of the lesson, the learner should be able to:
Test reactions with carbonates and hydrogen carbonates
Test neutralization with metal hydroxides and oxides
Identify products formed
Write balanced chemical equations

Experiments: (a) Add dilute HNO₃ to Na₂CO₃, CaCO₃, ZnCO₃, CuCO₃, NaHCO₃. Test gas evolved with lime water. (b) Neutralize NaOH, CaO, CuO, PbO with dilute HNO₃. Record color changes and write equations.

Various carbonates and hydroxides, Dilute nitric acid, Lime water, Universal indicator, Test tubes
Concentrated nitric acid, Iron(II) sulfate, Sulfur powder, Copper turnings, Test tubes, Fume cupboard access

KLB Secondary Chemistry Form 3, Pages 147-150

NITROGEN AND ITS COMPOUNDS

Uses of Nitric(V) Acid and Introduction to Nitrates
Action of Heat on Nitrates - Decomposition Patterns
Test for Nitrates - Brown Ring Test

By the end of the lesson, the learner should be able to:
List major industrial uses of nitric acid
Explain importance in fertilizer manufacture
Describe use in explosives and dyes
Introduce nitrate salts and their preparation
Test thermal decomposition of different nitrates
Classify decomposition patterns based on metal reactivity
Identify products formed on heating
Write equations for decomposition reactions

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.
Experiment: Heat KNO₃, NaNO₃, Zn(NO₃)₂, Cu(NO₃)₂, NH₄NO₃ separately. Test gases with glowing splint. Observe residues. Classification: Group I nitrates → nitrite + O₂; Group II → oxide + NO₂ + O₂; NH₄NO₃ → N₂O + H₂O.

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

KLB Secondary Chemistry Form 3, Pages 151
KLB Secondary Chemistry Form 3, Pages 151-153

NITROGEN AND ITS COMPOUNDS

Environmental Pollution by Nitrogen Compounds

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

KLB Secondary Chemistry Form 3, Pages 154-157

NITROGEN AND ITS COMPOUNDS

Pollution Control and Environmental Solutions
Comprehensive Problem Solving - Nitrogen Chemistry

By the end of the lesson, the learner should be able to:
Analyze methods to reduce nitrogen pollution
Design pollution control strategies
Evaluate effectiveness of current measures
Propose new solutions for environmental protection

Discussion and analysis: Catalytic converters in vehicles, sewage treatment, lime addition to soils/lakes, proper fertilizer application, industrial gas recycling. Group activity: Design pollution control strategy for local area. Evaluation of current measures.

Case studies, Pollution control technology information, Group activity worksheets, Local environmental data
Scientific calculators, Comprehensive problem sets, Industrial data sheets, Experimental result tables

KLB Secondary Chemistry Form 3, Pages 154-157

NITROGEN AND ITS COMPOUNDS

Laboratory Practical Assessment - Nitrogen Compounds

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

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.

Unknown nitrogen compounds, All laboratory chemicals and apparatus used in chapter, Safety equipment, Assessment rubrics

KLB Secondary Chemistry Form 3, Pages 119-157

NITROGEN AND ITS COMPOUNDS
SULPHUR AND ITS COMPOUNDS

Industrial Applications and Economic Importance
Chapter Review and Integration
Extraction of Sulphur
Allotropes of Sulphur
Physical Properties of Sulphur - Solubility

By the end of the lesson, the learner should be able to:
Evaluate economic importance of nitrogen industry
Analyze industrial production costs and benefits
Compare different manufacturing processes
Assess impact on agricultural productivity
Define sulphur and state its position in the periodic table. Describe the occurrence of sulphur in nature. Explain the Frasch process for extraction of sulphur. Evaluate the effectiveness of the Frasch process.

Case study analysis: Haber process economics, fertilizer industry impact, nitric acid production costs. Agricultural benefits: Crop yield improvements, food security. Economic calculations: Production costs, profit margins, environmental costs. Global nitrogen cycle importance.
Q/A: Review group VI elements and electron configuration of sulphur. Teacher demonstration: Using diagrams to explain the Frasch process setup. Discussion: Why ordinary mining is impossible for sulphur deposits. Group work: Students draw and label the Frasch process diagram.

Economic data sheets, Industry case studies, Agricultural statistics, Cost-benefit analysis templates
Concept mapping materials, Comparison charts, Flow diagram templates, Integration worksheets
Charts showing periodic table, Diagram of Frasch process, Samples of sulphur compounds (pyrites, gypsum)
Powdered sulphur, Carbon(IV) sulphide, Evaporating dish, Glass rod, Hand lens, Boiling tubes, Filter paper, Beakers
Powdered sulphur, Water, Benzene, Methylbenzene, Carbon(IV) sulphide, Test tubes, Charts showing molecular structure

KLB Secondary Chemistry Form 3, Pages 119-157
KLB Secondary Chemistry Form 4, Pages 160-161

SULPHUR AND ITS COMPOUNDS

Physical Properties of Sulphur - Effect of Heat
Chemical Properties of Sulphur - Reactions with Elements
Chemical Properties of Sulphur - Reactions with Acids

By the end of the lesson, the learner should be able to:
Investigate the effect of heat on sulphur. Describe changes in color and viscosity of molten sulphur. Explain the molecular changes occurring during heating. Identify "flowers of sulphur".

Practical work: Experiment 2(b) - Heating sulphur and observing changes. Observation: Color changes from yellow to amber to reddish-brown to black. Testing viscosity by inverting test tube. Demonstration: Sublimation of sulphur vapour. Discussion: Breaking of S8 rings to form long chains.

Powdered sulphur, Test tubes, Bunsen burner, Cold surface for condensation, Thermometer, Safety equipment
Sulphur, Iron powder, Copper powder, Oxygen gas jar, Deflagrating spoon, Moist litmus papers, Test tubes, Bunsen burner
Sulphur powder, Concentrated HNO3, Concentrated H2SO4, Concentrated HCl, Barium chloride solution, Test tubes, Fume cupboard access

KLB Secondary Chemistry Form 4, Pages 164-165

SULPHUR AND ITS COMPOUNDS

Uses of Sulphur and Introduction to Oxides
Preparation of Sulphur(IV) Oxide
Physical and Chemical Properties of Sulphur(IV) Oxide

By the end of the lesson, the learner should be able to:
List the uses of sulphur in industry and agriculture. Identify the two main oxides of sulphur. Compare sulphur(IV) oxide and sulphur(VI) oxide. Plan laboratory preparation methods for sulphur oxides.

Discussion: Industrial uses - sulphuric acid manufacture, fungicide, vulcanization of rubber, bleaching agents, dyes and fireworks. Q/A: Review oxidation states of sulphur in compounds. Introduction: SO2 and SO3 as important compounds. Preparation planning: Methods for laboratory preparation of SO

Charts showing uses of sulphur, Samples of vulcanized rubber, Fungicides, Industrial photographs, Textbook diagrams
Sodium sulphite, Dilute HCl, Round-bottomed flask, Delivery tubes, Gas jars, Concentrated H2SO4 for drying, Acidified potassium chromate(VI) paper
SO2 gas from previous preparation, Litmus papers, Universal indicator, 0.1M NaOH solution, Water, Test tubes, Safety equipment

KLB Secondary Chemistry Form 4, Pages 168-170

SULPHUR AND ITS COMPOUNDS

Bleaching Action of Sulphur(IV) Oxide

By the end of the lesson, the learner should be able to:
Investigate the bleaching properties of SO Compare SO2 bleaching with chlorine bleaching. Explain the mechanism of SO2 bleaching. Relate bleaching to paper manufacturing.

Practical work: Experiment 6 - Placing colored flower petals in SO2 gas. Observation: Temporary bleaching effect. Discussion: SO2 + H2O → H2SO3, reduction of organic dyes. Comparison: Permanent vs temporary bleaching. Application: Paper industry bleaching processes.

Colored flower petals (red/blue), SO2 gas jars, Hand lens for observation, Charts comparing bleaching agents

KLB Secondary Chemistry Form 4, Pages 173

SULPHUR AND ITS COMPOUNDS

Reducing Action of Sulphur(IV) Oxide
Oxidising Action of Sulphur(IV) Oxide
Test for Sulphate and Sulphite Ions & Uses of SO2

By the end of the lesson, the learner should be able to:
Investigate SO2 as a reducing agent. Test reactions with various oxidizing agents. Write ionic equations for redox reactions. Identify color changes in redox reactions.
Investigate SO2 as an oxidizing agent. Demonstrate reaction with stronger reducing agents. Explain the dual nature of SO Write equations for oxidation reactions by SO

Practical work: Experiment 7 - Testing SO2 with acidified potassium dichromate(VI), potassium manganate(VII), bromine water, iron(III) chloride. Recording observations in Table 6. Color changes: Orange to green, purple to colorless, brown to colorless, yellow to pale green. Writing half-equations and overall equations.
Practical work: Experiment 8 - Lowering burning magnesium into SO2 gas. Observation: Continued burning, white fumes of MgO, yellow specks of sulphur. Reaction with hydrogen sulphide gas (demonstration). Discussion: SO2 decomposition providing oxygen. Writing equations: 2Mg + SO2 → 2MgO + S.

SO2 gas, Acidified K2Cr2O7, Acidified KMnO4, Bromine water, Iron(III) chloride solution, Concentrated HNO3, Test tubes
SO2 gas jars, Magnesium ribbon, Deflagrating spoon, Hydrogen sulphide gas, Water droppers, Safety equipment
Sodium sulphate solution, Sodium sulphite solution, Barium chloride solution, Dilute HCl, Test tubes, Charts showing industrial uses

KLB Secondary Chemistry Form 4, Pages 173-176
KLB Secondary Chemistry Form 4, Pages 176-177

SULPHUR AND ITS COMPOUNDS

Large-scale Manufacture of Sulphuric(VI) Acid - Contact Process

By the end of the lesson, the learner should be able to:
Describe the contact process for manufacturing H2SO Identify raw materials and conditions used. Explain the role of catalyst in the process. Draw flow diagrams of the contact process.

Study of flow diagram: Figure 12 - Contact process. Discussion: Raw materials (sulphur, air), burning sulphur to SO Purification: Electrostatic precipitation, drying with H2SO Catalytic chamber: V2O5 catalyst at 450°C, 2-3 atmospheres. Formation of oleum: H2S2O7. Safety and environmental considerations.

Flow chart diagrams, Charts showing industrial plant, Samples of catalyst (V2O5), Photographs of Thika chemical plant, Calculator for percentage calculations

KLB Secondary Chemistry Form 4, Pages 179-181

SULPHUR AND ITS COMPOUNDS

Properties of Concentrated Sulphuric(VI) Acid - Dehydrating Properties
Properties of Concentrated Sulphuric(VI) Acid - Oxidizing Properties

By the end of the lesson, the learner should be able to:
Investigate the dehydrating properties of concentrated H2SO Demonstrate removal of water from hydrated salts. Show dehydration of organic compounds. Explain the hygroscopic nature of the acid.

Practical work: Experiment 10 - Adding concentrated H2SO4 to copper(II) sulphate crystals, sucrose crystals, ethanol. Observations: Blue to white crystals, charring of sugar, formation of ethene. Safety: Proper dilution technique - acid to water. Testing evolved gases. Discussion: Chemical vs physical dehydration.

Concentrated H2SO4, Copper(II) sulphate crystals, Sucrose, Ethanol, KMnO4 solution, Test tubes, Beakers, Safety equipment, Fume cupboard
Copper foil, Zinc granules, Charcoal powder, Concentrated H2SO4, Acidified K2Cr2O7 paper, Lime water, Test tubes, Bunsen burner

KLB Secondary Chemistry Form 4, Pages 181-183

SULPHUR AND ITS COMPOUNDS

Properties of Concentrated Sulphuric(VI) Acid - Displacement Reactions

By the end of the lesson, the learner should be able to:
Investigate acid displacement reactions. Demonstrate formation of volatile acids. Test the evolved gases for identification. Write equations for displacement reactions.

Practical work: Experiment 10 (continued) - Reactions with potassium nitrate and sodium chloride. Testing evolved gases with moist blue litmus, concentrated ammonia. Observations: Brown fumes (NO2), white fumes (HCl). Discussion: Less volatile acid displacing more volatile acids. Industrial applications.

Potassium nitrate crystals, Sodium chloride crystals, Concentrated H2SO4, Moist blue litmus paper, Concentrated ammonia, Test tubes, Bunsen burner

KLB Secondary Chemistry Form 4, Pages 184

SULPHUR AND ITS COMPOUNDS

Reactions of Dilute Sulphuric(VI) Acid - With Metals
Reactions of Dilute Sulphuric(VI) Acid - With Carbonates
Reactions of Dilute Sulphuric(VI) Acid - With Oxides and Hydroxides

By the end of the lesson, the learner should be able to:
Investigate reactions of dilute H2SO4 with metals. Compare reactivity of different metals. Test for hydrogen gas evolution. Relate reactions to reactivity series.
Investigate reactions of dilute H2SO4 with metal oxides and hydroxides. Identify neutralization reactions. Explain formation of insoluble sulphates. Write equations for acid-base reactions.

Practical work: Experiment 11 - Reactions with magnesium, zinc, copper. Testing evolved gas with burning splint. Recording observations in Table 10. Discussion: More reactive metals above hydrogen displace it. Vigour of reaction decreases down reactivity series. Writing ionic equations.
Practical work: Experiment 13 - Reactions with magnesium oxide, zinc oxide, copper(II) oxide, lead(II) oxide, sodium hydroxide. Recording observations in Table 1 Discussion: Salt and water formation, immediate stopping with lead(II) oxide due to insoluble PbSO Acid-base neutralization concept.

Magnesium ribbon, Zinc granules, Copper turnings, Dilute H2SO4, Test tubes, Burning splints, Reactivity series chart
Sodium carbonate, Zinc carbonate, Calcium carbonate, Copper(II) carbonate, Dilute H2SO4, Lime water, Test tubes
Metal oxides (MgO, ZnO, CuO, PbO), NaOH solution, 2M H2SO4, Test tubes, Bunsen burner for warming

KLB Secondary Chemistry Form 4, Pages 184-185
KLB Secondary Chemistry Form 4, Pages 186-187

SULPHUR AND ITS COMPOUNDS

Hydrogen Sulphide - Preparation and Physical Properties
Chemical Properties of Hydrogen Sulphide

By the end of the lesson, the learner should be able to:
Describe laboratory preparation of hydrogen sulphide. Set up apparatus for H2S preparation. State the physical properties of H2S. Explain the toxicity and safety precautions.

Demonstration: Figure 13 apparatus setup for H2S preparation. Reaction: FeS + 2HCl → FeCl2 + H2S. Collection over warm water due to solubility. Drying: Using anhydrous CaCl2 (not H2SO4). Properties: Colorless, rotten egg smell, poisonous, denser than air. Safety precautions in handling.

Iron(II) sulphide, Dilute HCl, Apparatus for gas generation, Anhydrous CaCl2, Gas jars, Safety equipment, Fume cupboard
H2S gas, Bromine water, Iron(III) chloride, KMnO4, K2Cr2O7, Metal salt solutions, Test tubes, Droppers

KLB Secondary Chemistry Form 4, Pages 187-188

SULPHUR AND ITS COMPOUNDS

Pollution Effects and Summary

By the end of the lesson, the learner should be able to:
Explain environmental pollution by sulphur compounds. Describe formation and effects of acid rain. Suggest methods to reduce sulphur pollution. Summarize key concepts of sulphur chemistry.

Discussion: Sources of SO2 pollution - burning fossil fuels, metal extraction, H2SO4 manufacture. Formation of acid rain: SO2 + H2O → H2SO3 → H2SO Effects: Plant damage, aquatic life destruction, building corrosion, soil acidification. Control measures: Scrubbing with Ca(OH)2, catalytic converters. Revision: Key reactions, properties, uses.

Charts showing pollution effects, Photographs of acid rain damage, Environmental data, Summary charts of reactions, Industrial pollution control diagrams

KLB Secondary Chemistry Form 4, Pages 190-194