NITROGEN AND ITS COMPOUNDS

Introduction to Nitrogen - Properties and Occurrence
Isolation of Nitrogen from Air - Industrial and Laboratory Methods

By the end of the lesson, the learner should be able to:
Describe position of nitrogen in the periodic table
State electron configuration of nitrogen
Identify natural occurrence of nitrogen
Explain why nitrogen exists as diatomic molecules

Teacher exposition: Nitrogen as Group V element, atomic number 7, electron arrangement Discussion: 78% of atmosphere is nitrogen. Q/A: Combined nitrogen in compounds - nitrates, proteins. Explanation: N≡N triple bond strength.

Periodic table charts, Atmospheric composition diagrams, Molecular models showing N≡N triple bond
Aspirator, KOH solution, Copper turnings, Heating apparatus, Fractional distillation flow chart

KLB Secondary Chemistry Form 3, Pages 119

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

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

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.

Property summary charts, Uses of nitrogen displays, Industrial application diagrams
Ammonium nitrate, Test tubes, Gas collection apparatus, Copper turnings, Sulfur, Glowing splints

KLB Secondary Chemistry Form 3, Pages 121-123

NITROGEN AND ITS COMPOUNDS

Nitrogen(II) Oxide - Preparation and Properties
Nitrogen(IV) Oxide - Preparation and Properties

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
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 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.
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, 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

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

NITROGEN AND ITS COMPOUNDS

Comparison of Nitrogen Oxides and Environmental Effects
Laboratory Preparation of Ammonia

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
Calcium hydroxide, Ammonium chloride, Round-bottomed flask, Calcium oxide, HCl solution, Glass rod, Litmus paper

KLB Secondary Chemistry Form 3, Pages 123-131

NITROGEN AND ITS COMPOUNDS

Preparation of Aqueous Ammonia and Solubility

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

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.

Ammonia generation apparatus, Funnel, Universal indicator, Fountain apparatus, pH meter/paper

KLB Secondary Chemistry Form 3, Pages 134-136

NITROGEN AND ITS COMPOUNDS

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

KLB Secondary Chemistry Form 3, Pages 136-138

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
List major uses of ammonia
Explain importance as fertilizer
Calculate nitrogen percentages in fertilizers
Compare different nitrogenous fertilizers

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.
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.

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

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

KLB Secondary Chemistry Form 3, Pages 144-145

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

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.

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

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
Action of Heat on Nitrates - Decomposition Patterns

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
Test thermal decomposition of different nitrates
Classify decomposition patterns based on metal reactivity
Identify products formed on heating
Write equations for decomposition reactions

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.
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.

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

KLB Secondary Chemistry Form 3, Pages 150-151
KLB Secondary Chemistry Form 3, Pages 151-153

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
NITROGEN AND ITS COMPOUNDS
SULPHUR AND ITS COMPOUNDS

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

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

KLB Secondary Chemistry Form 3, Pages 119-157

SULPHUR AND ITS COMPOUNDS

Allotropes of Sulphur
Physical Properties of Sulphur - Solubility
Physical Properties of Sulphur - Effect of Heat

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
Powdered sulphur, Test tubes, Bunsen burner, Cold surface for condensation, Thermometer, Safety equipment

KLB Secondary Chemistry Form 4, Pages 161-163

SULPHUR AND ITS COMPOUNDS

Chemical Properties of Sulphur - Reactions with Elements
Chemical Properties of Sulphur - Reactions with Acids
Uses of Sulphur and Introduction to Oxides

By the end of the lesson, the learner should be able to:
Investigate the reaction of sulphur with oxygen. Investigate the reaction of sulphur with metals. Write balanced equations for reactions of sulphur. Explain the formation of sulphides.

Practical work: Experiment 3(a) - Burning sulphur in oxygen using deflagrating spoon. Testing with moist litmus paper. Practical work: Heating mixtures of sulphur with iron powder and copper powder. Observation: Exothermic reactions and color changes. Writing equations: Fe + S → FeS, 2Cu + S → Cu2S.

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
Charts showing uses of sulphur, Samples of vulcanized rubber, Fungicides, Industrial photographs, Textbook diagrams

KLB Secondary Chemistry Form 4, Pages 165-167

SULPHUR AND ITS COMPOUNDS

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:
Describe laboratory preparation of sulphur(IV) oxide. Set up apparatus for gas preparation and collection. Write balanced equations for the preparation reactions. Explain the drying and collection methods used.

Practical work: Experiment 4 - Preparation of SO2 using sodium sulphite and dilute HCl. Apparatus setup: Round-bottomed flask, delivery tube, gas jars. Collection: Downward delivery method. Testing: Using acidified potassium chromate(VI) paper. Alternative method: Copper + concentrated H2SO

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 170-171

SULPHUR AND ITS COMPOUNDS

Bleaching Action of Sulphur(IV) Oxide
Reducing Action of Sulphur(IV) Oxide
Oxidising 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.
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 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.
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.

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

KLB Secondary Chemistry Form 4, Pages 173
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

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
Concentrated H2SO4, Copper(II) sulphate crystals, Sucrose, Ethanol, KMnO4 solution, Test tubes, Beakers, Safety equipment, Fume cupboard

KLB Secondary Chemistry Form 4, Pages 179-181

SULPHUR AND ITS COMPOUNDS

Properties of Concentrated Sulphuric(VI) Acid - Oxidizing Properties

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

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.

Copper foil, Zinc granules, Charcoal powder, Concentrated H2SO4, Acidified K2Cr2O7 paper, Lime water, Test tubes, Bunsen burner

KLB Secondary Chemistry Form 4, Pages 183-184

SULPHUR AND ITS COMPOUNDS

Properties of Concentrated Sulphuric(VI) Acid - Displacement Reactions
Reactions of Dilute Sulphuric(VI) Acid - With Metals
Reactions of Dilute Sulphuric(VI) Acid - With Carbonates

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.
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 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.
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.

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

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

SULPHUR AND ITS COMPOUNDS

Reactions of Dilute Sulphuric(VI) Acid - With Oxides and Hydroxides
Hydrogen Sulphide - Preparation and Physical Properties

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

Metal oxides (MgO, ZnO, CuO, PbO), NaOH solution, 2M H2SO4, Test tubes, Bunsen burner for warming
Iron(II) sulphide, Dilute HCl, Apparatus for gas generation, Anhydrous CaCl2, Gas jars, Safety equipment, Fume cupboard

KLB Secondary Chemistry Form 4, Pages 186-187

SULPHUR AND ITS COMPOUNDS

Chemical Properties of Hydrogen Sulphide

By the end of the lesson, the learner should be able to:
Investigate H2S as a reducing agent. Test reactions with oxidizing agents. Demonstrate precipitation of metal sulphides. Write ionic equations for redox reactions.

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.

H2S gas, Bromine water, Iron(III) chloride, KMnO4, K2Cr2O7, Metal salt solutions, Test tubes, Droppers

KLB Secondary Chemistry Form 4, Pages 188-190

SULPHUR AND ITS COMPOUNDS
CHLORINE AND ITS COMPOUNDS
CHLORINE AND ITS COMPOUNDS

Pollution Effects and Summary
Introduction and Preparation of Chlorine
Physical Properties of Chlorine

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
Manganese(IV) oxide, Concentrated HCl, Gas collection apparatus, Water, Concentrated H2SO4, Blue litmus paper, Gas jars
Preserved chlorine gas, Water trough, Gas jars, Observation tables, Safety equipment

KLB Secondary Chemistry Form 4, Pages 190-194

CHLORINE AND ITS COMPOUNDS

Chemical Properties of Chlorine - Reaction with Water
Chemical Properties of Chlorine - Reaction with Metals
Chemical Properties of Chlorine - Reaction with Non-metals
Oxidising Properties of Chlorine
Reaction of Chlorine with Alkali Solutions

By the end of the lesson, the learner should be able to:
Investigate the reaction of chlorine with water. Explain the formation of chlorine water. Test the acidic nature of chlorine water. Demonstrate the bleaching action of chlorine.
Investigate chlorine as an oxidizing agent. Test reactions with reducing agents. Write ionic equations for redox reactions. Identify color changes in oxidation reactions.

Practical work: Experiment 6.3 - Bubbling chlorine through water. Testing with litmus papers (dry vs moist). Testing with colored flower petals. Formation of green-yellow chlorine water. Writing equations: Cl2 + H2O → HCl + HOCl. Discussion: Formation of hypochlorous acid and hydrochloric acid.
Practical work: Experiment 6.6 - Bubbling chlorine through sodium sulphite solution, testing with barium nitrate and lead nitrate. Reactions with hydrogen sulphide and ammonia. Recording observations in Table 6. Color changes and precipitate formation. Writing ionic equations: SO3²⁻ + Cl2 + H2O → SO4²⁻ + 2Cl⁻ + 2H⁺.

Chlorine gas, Distilled water, Blue and red litmus papers, Colored flower petals, Gas jars, Boiling tubes
Magnesium ribbon, Iron wire, Chlorine gas, Deflagrating spoon, Combustion tube, Anhydrous CaCl2, Gas jars
Red phosphorus, Hydrogen gas, Chlorine gas, Deflagrating spoon, Gas jars, Bunsen burner, Safety equipment
Sodium sulphite solution, Barium nitrate, Lead nitrate, Hydrogen sulphide gas, Aqueous ammonia, Chlorine gas, Test tubes
Sodium hydroxide solutions (dilute cold, concentrated hot), Chlorine gas, Beakers, Bunsen burner, Thermometer

KLB Secondary Chemistry Form 4, Pages 197-199
KLB Secondary Chemistry Form 4, Pages 201-202

CHLORINE AND ITS COMPOUNDS

Oxidising Properties - Displacement Reactions
Test for Chloride Ions

By the end of the lesson, the learner should be able to:
Investigate displacement reactions of chlorine with halides. Test reactions with bromides and iodides. Write ionic equations for displacement reactions. Explain the order of reactivity of halogens.

Practical work: Experiment 6.8 - Bubbling chlorine through potassium bromide and potassium iodide solutions. Observations: Colorless to orange (Br2), colorless to brown (I2). Writing ionic equations: Cl2 + 2Br⁻ → 2Cl⁻ + Br2, Cl2 + 2I⁻ → 2Cl⁻ + I Discussion: Displacement as evidence of relative reactivity.

Potassium bromide solution, Potassium iodide solution, Chlorine gas, Test tubes, Observation charts
Sodium chloride, Concentrated H2SO4, Lead(II) nitrate solution, Aqueous ammonia, Glass rod, Test tubes, Bunsen burner

KLB Secondary Chemistry Form 4, Pages 203-204

CHLORINE AND ITS COMPOUNDS

Uses of Chlorine and its Compounds
Hydrogen Chloride - Laboratory Preparation

By the end of the lesson, the learner should be able to:
List the industrial uses of chlorine. Explain the use of chlorine in water treatment. Describe manufacture of chlorine compounds. Relate properties to uses of chlorine.

Discussion: Industrial applications - HCl manufacture, bleaching agents for cotton and paper industries, water treatment and sewage plants. Study Figure 6.3(a) - bleaching chemicals. Applications: Chloroform (anaesthetic), solvents (trichloroethane), CFCs, PVC plastics, pesticides (DDT), germicides and fungicides. Q/A: Relating chemical properties to practical applications.

Charts showing industrial uses, Samples of bleaching agents, PVC materials, Photographs of water treatment plants, Industrial application diagrams
Rock salt (NaCl), Concentrated H2SO4, Gas collection apparatus, Ammonia solution, Litmus papers, Water trough, Gas jars

KLB Secondary Chemistry Form 4, Pages 205-207

CHLORINE AND ITS COMPOUNDS

Chemical Properties of Hydrogen Chloride

By the end of the lesson, the learner should be able to:
Prepare aqueous hydrogen chloride (hydrochloric acid). Investigate acid properties of HCl solution. Test reactions with metals, bases, and carbonates. Compare HCl in water vs organic solvents.

Practical work: Experiment 6.11 - Preparation of aqueous HCl using apparatus in Figure 6. Testing with metals (Zn, Fe, Mg, Cu), NaOH, carbonates, lead nitrate. Recording observations in Table 6.7. Testing HCl in methylbenzene - no acid properties. Discussion: Ionization in water vs molecular existence in organic solvents. Writing equations for acid reactions.

Distilled water, Filter funnel, Metals (Zn, Fe, Mg, Cu), NaOH solution, Carbonates, Lead nitrate, Methylbenzene, Indicators

KLB Secondary Chemistry Form 4, Pages 208-211

CHLORINE AND ITS COMPOUNDS

Large-scale Manufacture of Hydrochloric Acid
Uses of Hydrochloric Acid
Environmental Pollution by Chlorine Compounds and Summary

By the end of the lesson, the learner should be able to:
Describe industrial production of hydrochloric acid. Identify raw materials and conditions used. Explain the controlled combustion process. Draw flow diagrams of the industrial process.
Explain environmental effects of chlorine compounds. Describe the impact of CFCs on ozone layer. Discuss pollution by chlorine-containing pesticides. Summarize key concepts of chlorine chemistry.

Study of Figure 6.4 - Large-scale manufacture setup. Discussion: Raw materials (H2 from electrolysis/cracking, Cl2 from electrolysis). Controlled combustion: H2 + Cl2 → 2HCl in jet burner. Dissolving HCl gas in water over glass beads. Safety: Explosive nature of H2/Cl2 mixture, use of excess chlorine. Industrial considerations: 35% concentration, transport in rubber-lined steel tanks.
Discussion: Environmental impacts - chlorine gas forming acid rain, CFCs (life span CCl3F = 75 years, CCl2F2 = 110 years) breaking down ozone layer. DDT as persistent pesticide, PVC as non-biodegradable plastic. NEMA role in environmental protection, Stockholm Convention on DDT. Control measures and alternatives. Revision: Key reactions, properties, uses, and environmental considerations. Summary of halogen chemistry concepts.

Flow diagrams, Industrial photographs, Glass beads samples, Charts showing electrolysis processes, Safety equipment models
Samples of rusted and cleaned metals, Photographic materials, pH control charts, Industrial application videos, Water treatment diagrams
Environmental pollution charts, Ozone layer diagrams, DDT restriction documents, PVC waste samples, NEMA guidelines, Summary charts of reactions

KLB Secondary Chemistry Form 4, Pages 211-212
KLB Secondary Chemistry Form 4, Pages 213-215