SULPHUR AND ITS COMPOUNDS

Extraction of Sulphur

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

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.

Charts showing periodic table, Diagram of Frasch process, Samples of sulphur compounds (pyrites, gypsum)

KLB Secondary Chemistry Form 4, Pages 160-161

SULPHUR AND ITS COMPOUNDS

Allotropes of Sulphur
Physical Properties of Sulphur - Solubility

By the end of the lesson, the learner should be able to:
Define allotropy and allotropes. Prepare rhombic sulphur in the laboratory. Prepare monoclinic sulphur in the laboratory. Compare the properties of rhombic and monoclinic sulphur.

Practical work: Experiment 1(a) - Preparation of rhombic sulphur using carbon(IV) sulphide. Practical work: Experiment 1(b) - Preparation of monoclinic sulphur by heating and cooling. Observation: Using hand lens to examine crystal shapes. Discussion: Compare crystal structures and transition temperature.

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 4, Pages 161-163

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
Bleaching Action 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.
Investigate the physical properties of SO2 gas. Test the solubility and acidity of SO Write equations for formation of sulphurous acid. Identify the acidic nature of SO

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
Practical work: Experiment 5 - Testing color, smell, solubility in water. Testing with dry and moist litmus papers. Universal indicator tests with water and NaOH. Formation of normal and acid salts. Recording observations in Table Safety: Proper ventilation due to toxic nature.

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

KLB Secondary Chemistry Form 4, Pages 168-170
KLB Secondary Chemistry Form 4, Pages 171-173

SULPHUR AND ITS COMPOUNDS

Reducing Action of Sulphur(IV) Oxide

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.

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.

SO2 gas, Acidified K2Cr2O7, Acidified KMnO4, Bromine water, Iron(III) chloride solution, Concentrated HNO3, Test tubes

KLB Secondary Chemistry Form 4, Pages 173-176

SULPHUR AND ITS COMPOUNDS

Oxidising Action of Sulphur(IV) Oxide

By the end of the lesson, the learner should be able to:
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 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 jars, Magnesium ribbon, Deflagrating spoon, Hydrogen sulphide gas, Water droppers, Safety equipment

KLB Secondary Chemistry Form 4, Pages 176-177

SULPHUR AND ITS COMPOUNDS

Test for Sulphate and Sulphite Ions & Uses of SO2

By the end of the lesson, the learner should be able to:
Carry out confirmatory tests for sulphate and sulphite ions. Distinguish between sulphate and sulphite using chemical tests. List the uses of sulphur(IV) oxide. Explain the applications in industry.

Practical work: Experiment 9 - Testing sodium sulphate and sodium sulphite with barium chloride. Adding dilute HCl to precipitates. Recording observations in Table 8. Discussion: BaSO4 insoluble in acid, BaSO3 dissolves. Uses: Raw material for H2SO4, bleaching wood pulp, fumigant, preservative.

Sodium sulphate solution, Sodium sulphite solution, Barium chloride solution, Dilute HCl, Test tubes, Charts showing industrial uses

KLB Secondary Chemistry Form 4, Pages 178-179

SULPHUR AND ITS COMPOUNDS

Large-scale Manufacture of Sulphuric(VI) Acid - Contact Process
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:
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.
Investigate the oxidizing properties of concentrated H2SO Test reactions with metals and non-metals. Identify the products of oxidation reactions. Write balanced equations for redox reactions.

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.
Practical work: Experiment 10 (continued) - Reactions with copper foil, zinc granules, charcoal. Testing evolved gases with acidified K2Cr2O7 paper, lime water. Observations: SO2 evolution, color changes. Discussion: H2SO4 → SO2 + H2O + [O]. Writing half-equations and overall equations.

Flow chart diagrams, Charts showing industrial plant, Samples of catalyst (V2O5), Photographs of Thika chemical plant, Calculator for percentage calculations
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 179-181
KLB Secondary Chemistry Form 4, Pages 183-184

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

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.

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.

Magnesium ribbon, Zinc granules, Copper turnings, Dilute H2SO4, Test tubes, Burning splints, Reactivity series chart

KLB Secondary Chemistry Form 4, Pages 184-185

SULPHUR AND ITS COMPOUNDS

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 carbonates. Test for carbon dioxide evolution. Explain why some reactions stop prematurely. Compare reactions of different metal carbonates.

Practical work: Experiment 12 - Reactions with sodium carbonate, zinc carbonate, calcium carbonate, copper(II) carbonate. Testing evolved gas with lime water. Recording observations in Table 1 Discussion: Formation of insoluble calcium sulphate coating. Effervescence and CO2 identification.

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 185-186

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.
Investigate H2S as a reducing agent. Test reactions with oxidizing agents. Demonstrate precipitation of metal sulphides. Write ionic equations for redox reactions.

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.
Practical demonstrations: H2S with bromine water, iron(III) chloride, acidified KMnO4, K2Cr2O7. Precipitation tests: H2S with copper(II) sulphate, lead(II) nitrate, zinc sulphate. Color changes: Brown to colorless, yellow to green, purple to colorless. Formation of black, yellow, and white precipitates.

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
KLB Secondary Chemistry Form 4, Pages 188-190

SULPHUR AND ITS COMPOUNDS
NITROGEN AND ITS COMPOUNDS

Pollution Effects and Summary
Introduction to Nitrogen - Properties and Occurrence

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
Periodic table charts, Atmospheric composition diagrams, Molecular models showing N≡N triple bond

KLB Secondary Chemistry Form 4, Pages 190-194

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

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

KLB Secondary Chemistry Form 3, Pages 121-123

NITROGEN AND ITS COMPOUNDS

Properties and Uses of Nitrogen Gas
Nitrogen(I) Oxide - Preparation and Properties
Nitrogen(II) Oxide - Preparation and Properties

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

Analysis of test results: Colorless, odorless, does not burn or support combustion. Discussion: Triple bond strength and chemical inertness. High temperature reactions with metals forming nitrides. Uses: Haber process, light bulbs, refrigerant, inert atmosphere.
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.

Property summary charts, Uses of nitrogen displays, Industrial application diagrams
Ammonium nitrate, Test tubes, Gas collection apparatus, Copper turnings, Sulfur, Glowing splints
Copper turnings, Dilute nitric acid, Gas collection apparatus, Iron(II) sulfate solution, Test reagents

KLB Secondary Chemistry Form 3, Pages 121-123
KLB Secondary Chemistry Form 3, Pages 123-125

NITROGEN AND ITS COMPOUNDS

Nitrogen(IV) Oxide - Preparation and Properties

By the end of the lesson, the learner should be able to:
Prepare nitrogen(IV) oxide from copper and concentrated nitric acid
Prepare from thermal decomposition of nitrates
Test properties including equilibrium with N₂O₄
Describe reactions and uses

Experiment: Add concentrated HNO₃ to copper turnings. Collect red-brown gas by downward delivery. Alternative: Heat lead(II) nitrate with cooling U-tube. Tests: Solubility, effect on litmus, burning elements, cooling/heating effects.

Copper turnings, Concentrated nitric acid, Lead(II) nitrate, Gas collection apparatus, U-tube with ice, Testing materials

KLB Secondary Chemistry Form 3, Pages 127-131

NITROGEN AND ITS COMPOUNDS

Comparison of Nitrogen Oxides and Environmental Effects

By the end of the lesson, the learner should be able to:
Compare preparation methods of nitrogen oxides
Distinguish between different nitrogen oxides
Explain formation in vehicle engines
Describe environmental pollution effects

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.

Comparison charts, Environmental impact diagrams, Vehicle emission illustrations

KLB Secondary Chemistry Form 3, Pages 123-131

NITROGEN AND ITS COMPOUNDS

Laboratory Preparation of Ammonia

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

KLB Secondary Chemistry Form 3, Pages 131-134

NITROGEN AND ITS COMPOUNDS

Preparation of Aqueous Ammonia and Solubility
Reactions of Aqueous Ammonia with Metal Ions
Chemical Properties of Ammonia - Reactions with Acids and Combustion

By the end of the lesson, the learner should be able to:
Prepare aqueous ammonia solution
Demonstrate high solubility using fountain experiment
Explain alkaline properties of aqueous ammonia
Write equations for ammonia in water
Test neutralization reactions with acids
Investigate combustion of ammonia
Examine catalytic oxidation with platinum
Study reducing properties with metal oxides

Experiment: Dissolve ammonia in water using inverted funnel method. Fountain experiment: Show partial vacuum formation due to high solubility. Tests: Effect on universal indicator, pH measurement. Theory: NH₃ + H₂O equilibrium.
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.

Ammonia generation apparatus, Funnel, Universal indicator, Fountain apparatus, pH meter/paper
Various metal salt solutions, Aqueous ammonia, Test tubes, Droppers, Observation recording tables
Various dilute acids, Methyl orange, Oxygen supply, Platinum wire, Copper(II) oxide, Combustion apparatus, U-tube for collection

KLB Secondary Chemistry Form 3, Pages 134-136
KLB Secondary Chemistry Form 3, Pages 138-140

NITROGEN AND ITS COMPOUNDS

Industrial Manufacture of Ammonia - The Haber Process

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

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.

Haber process flow charts, Industrial diagrams, Catalyst samples, Economic analysis sheets

KLB Secondary Chemistry Form 3, Pages 140-141

NITROGEN AND ITS COMPOUNDS

Uses of Ammonia and Introduction to Nitrogenous Fertilizers

By the end of the lesson, the learner should be able to:
List major uses of ammonia
Explain importance as fertilizer
Calculate nitrogen percentages in fertilizers
Compare different nitrogenous fertilizers

Discussion: Uses - fertilizer, refrigerant, cleaning agent, hydrazine production. Introduction to fertilizers: Ammonium sulfate, ammonium nitrate, ammonium phosphate, urea, CAN. Calculations: Percentage nitrogen content in each fertilizer type.

Fertilizer samples, Percentage calculation worksheets, Use application charts, Calculator

KLB Secondary Chemistry Form 3, Pages 141-144

NITROGEN AND ITS COMPOUNDS

Nitrogenous Fertilizers - Types and Calculations
Laboratory Preparation of Nitric(V) Acid

By the end of the lesson, the learner should be able to:
Calculate percentage nitrogen in various fertilizers
Compare fertilizer effectiveness
Prepare simple nitrogenous fertilizers
Discuss environmental considerations

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.

Various fertilizer formulas, Scientific calculators, Laboratory preparation materials, Environmental impact data
Potassium nitrate, Concentrated sulfuric acid, All-glass apparatus, Condenser, Retort stand, Safety equipment

KLB Secondary Chemistry Form 3, Pages 141-144

NITROGEN AND ITS COMPOUNDS

Industrial Manufacture of Nitric(V) Acid
Reactions of Dilute Nitric(V) Acid with Metals

By the end of the lesson, the learner should be able to:
Describe catalytic oxidation process
Explain raw materials and conditions
Draw flow diagram of industrial process
Calculate theoretical yields and efficiency
Test reactions with various metals
Explain absence of hydrogen gas production
Observe formation of nitrogen oxides
Write equations for metal-acid reactions

Teacher exposition: Ostwald process - NH₃ oxidation with Pt-Rh catalyst at 900°C. Flow diagram: Oxidation chamber, cooling, absorption tower. Equations: NH₃ → NO → NO₂ → HNO₃. Economic factors: Catalyst cost, heat recovery.
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.

Industrial process flow charts, Catalyst samples, Process condition charts, Efficiency calculation sheets
Various metals (Mg, Zn, Cu), Dilute nitric acid, Test tubes, Gas testing apparatus, Burning splints

KLB Secondary Chemistry Form 3, Pages 145-147
KLB Secondary Chemistry Form 3, Pages 147-150

NITROGEN AND ITS COMPOUNDS

Reactions of Dilute Nitric(V) Acid with Carbonates and Hydroxides

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

KLB Secondary Chemistry Form 3, Pages 147-150

NITROGEN AND ITS COMPOUNDS

Reactions of Concentrated Nitric(V) Acid - Oxidizing Properties
Uses of Nitric(V) Acid and Introduction to Nitrates

By the end of the lesson, the learner should be able to:
Demonstrate strong oxidizing properties
Test reactions with FeSO₄, sulfur, and copper
Observe formation of nitrogen dioxide
Explain electron transfer in oxidation

Experiments: (a) Add concentrated HNO₃ to acidified FeSO₄ - observe color change. (b) Add to sulfur - observe reaction. (c) Add to copper turnings - observe vigorous reaction and brown fumes. Explain oxidizing power and reduction to NO₂.

Concentrated nitric acid, Iron(II) sulfate, Sulfur powder, Copper turnings, Test tubes, Fume cupboard access
Industrial use charts, Nitrate salt samples, Preparation method diagrams, Safety data sheets

KLB Secondary Chemistry Form 3, Pages 150-151

NITROGEN AND ITS COMPOUNDS

Action of Heat on Nitrates - Decomposition Patterns

By the end of the lesson, the learner should be able to:
Test thermal decomposition of different nitrates
Classify decomposition patterns based on metal reactivity
Identify products formed on heating
Write equations for decomposition reactions

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.

Various nitrate salts, Test tubes, Bunsen burner, Gas collection apparatus, Glowing splints, Observation recording sheets

KLB Secondary Chemistry Form 3, Pages 151-153

NITROGEN AND ITS COMPOUNDS

Test for Nitrates - Brown Ring Test
Environmental Pollution by Nitrogen Compounds

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
Explain sources of nitrogen pollution
Describe formation of acid rain
Discuss effects on environment and health
Evaluate pollution control measures

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.
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.

Sodium nitrate, Fresh FeSO₄ solution, Concentrated H₂SO₄, Copper turnings, Test tubes, Unknown nitrate samples
Environmental pollution charts, Acid rain effect photos, Vehicle emission diagrams, Control measure illustrations

KLB Secondary Chemistry Form 3, Pages 153-154
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

Industrial Applications and Economic Importance

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

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.

Economic data sheets, Industry case studies, Agricultural statistics, Cost-benefit analysis templates

KLB Secondary Chemistry Form 3, Pages 119-157

NITROGEN AND ITS COMPOUNDS
GAS LAWS
GAS LAWS

Chapter Review and Integration
Boyle's Law - Introduction and Experimental Investigation
Boyle's Law - Mathematical Expression and Graphical Representation
Boyle's Law - Numerical Problems and Applications
Charles's Law - Introduction and Temperature Scales

By the end of the lesson, the learner should be able to:
Synthesize all nitrogen chemistry concepts
Compare preparation methods for nitrogen compounds
Relate structure to properties and reactivity
Connect laboratory and industrial processes
Solve numerical problems involving Boyle's law
Convert between different pressure units
Apply Boyle's law to real-life situations
Calculate volumes and pressures using P₁V₁ = P₂V₂

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.
Worked examples: Demonstrate step-by-step problem solving. Supervised practice: Students solve problems involving pressure and volume calculations. Convert units (mmHg, atm, Pa). Discuss applications in tire inflation, aerosol cans. Assignment: Additional practice problems.

Concept mapping materials, Comparison charts, Flow diagram templates, Integration worksheets
Bicycle pump, Syringes, Gas jars, Chart showing volume-pressure relationship
Graph papers, Scientific calculators, Chart showing mathematical expressions
Scientific calculators, Worked example charts, Unit conversion tables
Round-bottomed flask, Narrow glass tube, Colored water, Rubber bung, Hot and cold water baths

KLB Secondary Chemistry Form 3, Pages 119-157
KLB Secondary Chemistry Form 3, Pages 4-5

GAS LAWS

Charles's Law - Experimental Investigation and Mathematical Expression
Charles's Law - Numerical Problems and Applications
Combined Gas Law and Standard Conditions

By the end of the lesson, the learner should be able to:
Investigate relationship between volume and temperature
Express Charles's law mathematically
Plot volume vs temperature graphs
Extrapolate graphs to find absolute zero

Class experiment: Volume-temperature relationship using flask and capillary tube. Record data at different temperatures. Plot graphs: volume vs temperature (°C) and volume vs absolute temperature (K). Extrapolate graph to find absolute zero. Derive V₁/T₁ = V₂/T₂ equation.

Glass apparatus, Thermometers, Graph papers, Water baths at different temperatures
Scientific calculators, Temperature conversion charts, Application examples
Scientific calculators, Combined law derivation charts, Standard conditions reference table

KLB Secondary Chemistry Form 3, Pages 8-10

GAS LAWS

Introduction to Diffusion - Experimental Investigation
Rates of Diffusion - Comparative Study

By the end of the lesson, the learner should be able to:
Define diffusion process
Investigate diffusion in liquids and gases
Compare rates of diffusion in different media
Explain diffusion using kinetic theory

Class experiments: (a) KMnO₄ crystal in water - observe spreading over time. (b) Bromine vapor in gas jars - observe color distribution. (c) Ammonia gas in combustion tube with litmus paper. Record observations over time. Discuss particle movement and kinetic energy.

KMnO₄ crystals, Bromine liquid, Gas jars, Combustion tube, Litmus papers, Stopwatch
Glass tube (25cm), Cotton wool, Concentrated NH₃ and HCl, Stopwatch, Ruler, Safety equipment

KLB Secondary Chemistry Form 3, Pages 14-16

GAS LAWS

Graham's Law of Diffusion - Theory and Mathematical Expression

By the end of the lesson, the learner should be able to:
State Graham's law of diffusion
Express Graham's law mathematically
Relate diffusion rate to molecular mass and density
Explain the inverse relationship between rate and √molecular mass

Teacher exposition: Graham's law statement and mathematical derivation. Discussion: Rate ∝ 1/√density and Rate ∝ 1/√molecular mass. Derive comparative expressions for two gases. Explain relationship between density and molecular mass. Practice: Identify faster diffusing gas from molecular masses.

Graham's law charts, Molecular mass tables, Mathematical derivation displays

KLB Secondary Chemistry Form 3, Pages 18-20

GAS LAWS
THE MOLE

Graham's Law - Numerical Applications and Problem Solving
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:
Solve numerical problems using Graham's law
Calculate relative rates of diffusion
Determine molecular masses from diffusion data
Compare diffusion times for equal volumes of gases
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

Worked examples: Calculate relative diffusion rates using √(M₂/M₁). Problems involving time comparisons for equal volumes. Calculate unknown molecular masses from rate data. Supervised practice: Various Graham's law calculations. Real-life applications: gas separation, gas masks.
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.

Scientific calculators, Worked example charts, Molecular mass reference tables
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 20-22
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

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

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

KLB Secondary Chemistry Form 3, Pages 32-35

THE MOLE

Empirical Formula - Reduction Method
Empirical Formula - Percentage Composition Method
Molecular Formula - Determination from Empirical Formula
Molecular Formula - Combustion Analysis

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
Define molecular formula
Relate molecular formula to empirical formula
Calculate molecular formula using molecular mass
Apply the relationship (empirical formula)ₙ = molecular formula

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.
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.

Combustion tube, Porcelain boat, Copper(II) oxide, Laboratory gas, Beam balance, Bunsen burner
Scientific calculators, Percentage composition charts, Worked example displays
Scientific calculators, Molecular mass charts, Worked example displays
Scientific calculators, Combustion analysis charts, Molecular models of hydrocarbons

KLB Secondary Chemistry Form 3, Pages 35-37
KLB Secondary Chemistry Form 3, Pages 38-40