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
Nitrogenous Fertilizers - Types and Calculations

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
Calculate percentage nitrogen in various fertilizers
Compare fertilizer effectiveness
Prepare simple nitrogenous fertilizers
Discuss environmental considerations

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.
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.

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 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

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

KLB Secondary Chemistry Form 3, Pages 145-147

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
Demonstrate strong oxidizing properties
Test reactions with FeSO₄, sulfur, and copper
Observe formation of nitrogen dioxide
Explain electron transfer in oxidation

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.
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.

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
KLB Secondary Chemistry Form 3, Pages 150-151

NITROGEN AND ITS COMPOUNDS

Uses of Nitric(V) Acid and Introduction to Nitrates

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

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.

Industrial use charts, Nitrate salt samples, Preparation method diagrams, Safety data sheets

KLB Secondary Chemistry Form 3, Pages 151

NITROGEN AND ITS COMPOUNDS

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

KLB Secondary Chemistry Form 3, Pages 151-153

SULPHUR AND ITS COMPOUNDS

Extraction of Sulphur
Allotropes 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)
Powdered sulphur, Carbon(IV) sulphide, Evaporating dish, Glass rod, Hand lens, Boiling tubes, Filter paper, Beakers

KLB Secondary Chemistry Form 4, Pages 160-161

SULPHUR AND ITS COMPOUNDS

Physical Properties of Sulphur - Solubility
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 solubility of sulphur in different solvents. Explain the molecular structure of sulphur. Compare solubility in polar and non-polar solvents. State the physical properties of sulphur.
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 2(a) - Testing solubility of sulphur in water, benzene, methylbenzene, and carbon(IV) sulphide. Observation and recording in Table Discussion: Explain why sulphur dissolves in organic solvents but not water. Drawing: Puckered ring structure of S8 molecule.
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.

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
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 163-164
KLB Secondary Chemistry Form 4, Pages 165-167

SULPHUR AND ITS COMPOUNDS

Uses of Sulphur and Introduction to Oxides
Preparation 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

KLB Secondary Chemistry Form 4, Pages 168-170

SULPHUR AND ITS COMPOUNDS

Physical and Chemical Properties of Sulphur(IV) Oxide

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

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.

SO2 gas from previous preparation, Litmus papers, Universal indicator, 0.1M NaOH solution, Water, Test tubes, Safety equipment

KLB Secondary Chemistry Form 4, Pages 171-173

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

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

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

SULPHUR AND ITS COMPOUNDS

Test for Sulphate and Sulphite Ions & Uses of SO2
Large-scale Manufacture of Sulphuric(VI) Acid - Contact Process

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
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 178-179

SULPHUR AND ITS COMPOUNDS

Properties of Concentrated Sulphuric(VI) Acid - Dehydrating 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

KLB Secondary Chemistry Form 4, Pages 181-183

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

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 metals. Compare reactivity of different metals. Test for hydrogen gas evolution. Relate reactions to reactivity series.

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 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.

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

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

SULPHUR AND ITS COMPOUNDS

Reactions of Dilute Sulphuric(VI) Acid - With Carbonates

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

KLB Secondary Chemistry Form 4, Pages 185-186

SULPHUR AND ITS COMPOUNDS

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 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

KLB Secondary Chemistry Form 4, Pages 186-187

SULPHUR AND ITS COMPOUNDS

Hydrogen Sulphide - Preparation and Physical Properties

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

KLB Secondary Chemistry Form 4, Pages 187-188

SULPHUR AND ITS COMPOUNDS

Chemical Properties of Hydrogen Sulphide
Pollution Effects and Summary

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.
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.

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.
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.

H2S gas, Bromine water, Iron(III) chloride, KMnO4, K2Cr2O7, Metal salt solutions, Test tubes, Droppers
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 188-190
KLB Secondary Chemistry Form 4, Pages 190-194

CHLORINE AND ITS COMPOUNDS

Introduction and Preparation of Chlorine
Physical Properties of Chlorine
Chemical Properties of Chlorine - Reaction with Water

By the end of the lesson, the learner should be able to:
Define chlorine and state its position in the periodic table. Describe the occurrence of chlorine in nature. Describe laboratory preparation of chlorine gas. Write balanced equations for chlorine preparation.

Q/A: Review Group VII elements and electron configuration of chlorine ( 8.7). Discussion: Occurrence as sodium chloride in sea water and rock salt. Practical work: Experiment 6.1 - Preparation using MnO2 + concentrated HCl. Setup apparatus as in Figure 6. Safety precautions for handling chlorine gas.

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
Chlorine gas, Distilled water, Blue and red litmus papers, Colored flower petals, Gas jars, Boiling tubes

KLB Secondary Chemistry Form 4, Pages 195-196

CHLORINE AND ITS COMPOUNDS

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

By the end of the lesson, the learner should be able to:
Investigate reactions of chlorine with metals. Write balanced equations for metal-chlorine reactions. Explain the formation of metal chlorides. Demonstrate exothermic nature of these reactions.

Practical work: Experiment 6.4 - Reactions with burning magnesium, hot iron wire, dry chlorine over hot iron coil (Figure 6.2). Recording observations in Table 6. Observations: White fumes (MgCl2), glowing iron wire, black crystals (FeCl3). Discussion: Formation of higher oxidation state chlorides. Safety: Proper ventilation and eye protection.

Magnesium ribbon, Iron wire, Chlorine gas, Deflagrating spoon, Combustion tube, Anhydrous CaCl2, Gas jars
Red phosphorus, Hydrogen gas, Chlorine gas, Deflagrating spoon, Gas jars, Bunsen burner, Safety equipment

KLB Secondary Chemistry Form 4, Pages 199-201

CHLORINE AND ITS COMPOUNDS

Oxidising Properties of Chlorine
Reaction of Chlorine with Alkali Solutions

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

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

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

KLB Secondary Chemistry Form 4, Pages 201-202

CHLORINE AND ITS COMPOUNDS

Oxidising Properties - Displacement Reactions
Test for Chloride Ions
Uses of Chlorine and its Compounds

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.
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.

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.
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.

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
Charts showing industrial uses, Samples of bleaching agents, PVC materials, Photographs of water treatment plants, Industrial application diagrams

KLB Secondary Chemistry Form 4, Pages 203-204
KLB Secondary Chemistry Form 4, Pages 205-207

CHLORINE AND ITS COMPOUNDS

Hydrogen Chloride - Laboratory Preparation

By the end of the lesson, the learner should be able to:
Describe laboratory preparation of hydrogen chloride gas. Set up apparatus for HCl preparation. Investigate physical properties of HCl gas. Explain the method of collection used.

Practical work: Experiment 6.10 - Preparation using rock salt (NaCl) + concentrated H2SO Setup apparatus as in Figure 6.3(b). Testing physical properties and recording in Table 6.6. Tests: Solubility (fountain experiment), reaction with ammonia, effect on litmus. Collection by downward delivery due to density. Writing equation: NaCl + H2SO4 → NaHSO4 + HCl.

Rock salt (NaCl), Concentrated H2SO4, Gas collection apparatus, Ammonia solution, Litmus papers, Water trough, Gas jars

KLB Secondary Chemistry Form 4, Pages 207-208

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

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

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

Flow diagrams, Industrial photographs, Glass beads samples, Charts showing electrolysis processes, Safety equipment models

KLB Secondary Chemistry Form 4, Pages 211-212

CHLORINE AND ITS COMPOUNDS

Uses of Hydrochloric Acid

By the end of the lesson, the learner should be able to:
List the industrial uses of hydrochloric acid. Explain applications in metal treatment. Describe use in water treatment and manufacturing. Relate acid properties to industrial applications.

Discussion: Applications - rust removal and descaling, galvanizing preparation, electroplating preparation, water treatment (chlorination), sewage treatment. Manufacturing uses: dyes, drugs, photographic materials (AgCl), pH control in industries. Q/A: How acid properties make HCl suitable for these uses. Case studies: Metal cleaning processes, water purification systems.

Samples of rusted and cleaned metals, Photographic materials, pH control charts, Industrial application videos, Water treatment diagrams

KLB Secondary Chemistry Form 4, Pages 212-213

CHLORINE AND ITS COMPOUNDS

Environmental Pollution by Chlorine Compounds and Summary

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

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

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

KLB Secondary Chemistry Form 4, Pages 213-215