THE MOLE

Standardization of Solutions

By the end of the lesson, the learner should be able to:
Define standardization process
Standardize HCl using Na₂CO₃ as primary standard
Calculate accurate concentrations from titration data
Understand importance of primary standards

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

Anhydrous Na₂CO₃, Approximately 0.1M HCl, Methyl orange, Volumetric flasks, Analytical balance

KLB Secondary Chemistry Form 3, Pages 65-67

THE MOLE

Back Titration Method

By the end of the lesson, the learner should be able to:
Understand principle of back titration
Apply back titration to determine composition
Calculate concentrations using back titration data
Determine atomic masses from back titration

Experiment: Determine atomic mass of divalent metal in MCO₃. Add excess HCl to carbonate, then titrate excess with NaOH. Calculate moles of acid that reacted with carbonate. Determine metal's atomic mass.

Metal carbonate sample, 0.5M HCl, 0M NaOH, Phenolphthalein, Conical flasks

KLB Secondary Chemistry Form 3, Pages 67-70

THE MOLE

Redox Titrations - Principles

By the end of the lesson, the learner should be able to:
Explain principles of redox titrations
Identify color changes in redox reactions
Understand self-indicating nature of some redox reactions
Write ionic equations for redox processes

Teacher exposition: Redox titration principles. Demonstrate color changes: MnO₄⁻ (purple) → Mn²⁺ (colorless), Cr₂O₇²⁻ (orange) → Cr³⁺ (green). Discussion: Self-indicating reactions. Write half-equations and overall ionic equations.

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

KLB Secondary Chemistry Form 3, Pages 68-70

THE MOLE

Redox Titrations - KMnO₄ Standardization
Water of Crystallization Determination

By the end of the lesson, the learner should be able to:
Standardize KMnO₄ solution using iron(II) salt
Calculate molarity from redox titration data
Apply 1:5 mole ratio in calculations
Prepare solutions for redox titrations
Determine water of crystallization in hydrated salts
Use redox titration to find formula of hydrated salt
Calculate value of 'n' in crystallization formulas
Apply analytical data to determine complete formulas

Experiment: Standardize KMnO₄ using FeSO₄(NH₄)₂SO₄·6H₂O. Dissolve iron salt in boiled, cooled water. Titrate with KMnO₄ until persistent pink color. Calculate molarity using 5:1 mole ratio.
Experiment: Determine 'n' in FeSO₄(NH₄)₂SO₄·nH₂O. Dissolve known mass in acid, titrate with standardized KMnO₄. Calculate moles of iron(II), hence complete formula. Compare theoretical and experimental values.

Iron(II) ammonium sulfate, KMnO₄ solution, Dilute H₂SO₄, Pipettes, Burettes
Hydrated iron(II) salt, Standardized KMnO₄, Dilute H₂SO₄, Analytical balance

KLB Secondary Chemistry Form 3, Pages 70-72
KLB Secondary Chemistry Form 3, Pages 72-73

THE MOLE

Atomicity and Molar Gas Volume

By the end of the lesson, the learner should be able to:
Define atomicity of gaseous elements
Classify gases as monoatomic, diatomic, or triatomic
Determine molar gas volume experimentally
Calculate gas densities and molar masses

Experiment: Measure volumes and masses of different gases (O₂, CO₂, Cl₂). Calculate densities and molar masses. Determine volume occupied by one mole. Compare values at different conditions.

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

KLB Secondary Chemistry Form 3, Pages 73-75

THE MOLE

Combining Volumes of Gases - Experimental Investigation

By the end of the lesson, the learner should be able to:
Investigate Gay-Lussac's law experimentally
Measure combining volumes of reacting gases
Determine simple whole number ratios
Write equations from volume relationships

Experiment: React NH₃ and HCl gases in measured volumes. Observe formation of NH₄Cl solid. Measure residual gas volumes. Determine combining ratios. Apply to other gas reactions.

Gas syringes, Dry NH₃ generator, Dry HCl generator, Glass connecting tubes, Clips

KLB Secondary Chemistry Form 3, Pages 75-77

THE MOLE

Gas Laws and Chemical Equations

By the end of the lesson, the learner should be able to:
Apply Avogadro's law to chemical reactions
Use volume ratios to determine chemical equations
Calculate product volumes from reactant volumes
Solve problems involving gas stoichiometry

Worked examples: Use Gay-Lussac's law to determine equations. Calculate volumes of products from given reactant volumes. Apply Avogadro's law to find number of molecules. Practice: Complex gas stoichiometry problems.

Scientific calculators, Gas law charts, Volume ratio examples

KLB Secondary Chemistry Form 3, Pages 77-79

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
Describe isolation of nitrogen from air
Explain fractional distillation of liquid air
Set up apparatus for laboratory isolation
Identify impurities removed during isolation

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.
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.

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
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

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

KLB Secondary Chemistry Form 3, Pages 121-123

NITROGEN AND ITS COMPOUNDS

Nitrogen(I) Oxide - Preparation and Properties

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

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

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

KLB Secondary Chemistry Form 3, Pages 123-125

NITROGEN AND ITS COMPOUNDS

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

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

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

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
Test neutralization reactions with acids
Investigate combustion of ammonia
Examine catalytic oxidation with platinum
Study reducing properties with metal oxides

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

Various 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
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

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

KLB Secondary Chemistry Form 3, Pages 141-144

NITROGEN AND ITS COMPOUNDS

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

By the end of the lesson, the learner should be able to:
Prepare nitric acid from nitrate and concentrated sulfuric acid
Set up all-glass apparatus safely
Explain brown fumes and yellow color
Purify nitric acid by air bubbling
Describe catalytic oxidation process
Explain raw materials and conditions
Draw flow diagram of industrial process
Calculate theoretical yields and efficiency

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.
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.

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

KLB Secondary Chemistry Form 3, Pages 144-145
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

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
SULPHUR AND ITS COMPOUNDS

Reactions of Concentrated Nitric(V) Acid - Oxidizing Properties
Extraction of Sulphur

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

KLB Secondary Chemistry Form 3, Pages 150-151

SULPHUR AND ITS COMPOUNDS

Allotropes of Sulphur
Physical Properties of Sulphur - Solubility
Physical Properties of Sulphur - Effect of Heat
Chemical Properties of Sulphur - Reactions with Elements

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.
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 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.
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, 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
Sulphur, Iron powder, Copper powder, Oxygen gas jar, Deflagrating spoon, Moist litmus papers, Test tubes, Bunsen burner

KLB Secondary Chemistry Form 4, Pages 161-163
KLB Secondary Chemistry Form 4, Pages 164-165

SULPHUR AND ITS COMPOUNDS

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 concentrated acids. Identify the products formed in these reactions. Write balanced equations for oxidation reactions. Test for sulphate ions using barium chloride.

Practical work: Experiment 3(b) - Reactions with concentrated nitric(V) acid, sulphuric(VI) acid, and hydrochloric acid. Testing with barium chloride solution. Observation: Formation of sulphate ions, brown fumes, no reaction with HCl. Discussion: Sulphur as a reducing agent, acids as oxidizing agents.

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 167-168

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

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

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

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

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

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

KLB Secondary Chemistry Form 4, Pages 179-181

SULPHUR AND ITS COMPOUNDS

Properties of Concentrated Sulphuric(VI) Acid - Dehydrating Properties

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
Properties of Concentrated Sulphuric(VI) Acid - Displacement Reactions

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.
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 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.
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.

Copper foil, Zinc granules, Charcoal powder, Concentrated H2SO4, Acidified K2Cr2O7 paper, Lime water, Test tubes, Bunsen burner
Potassium nitrate crystals, Sodium chloride crystals, Concentrated H2SO4, Moist blue litmus paper, Concentrated ammonia, Test tubes, Bunsen burner

KLB Secondary Chemistry Form 4, Pages 183-184
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

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
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

Pollution Effects and Summary

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

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

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

KLB Secondary Chemistry Form 4, Pages 190-194