NITROGEN AND ITS COMPOUNDS

Reactions of Aqueous Ammonia with Metal Ions

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

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

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

KLB Secondary Chemistry Form 3, Pages 136-138

NITROGEN AND ITS COMPOUNDS

Chemical Properties of Ammonia - Reactions with Acids and Combustion
Industrial Manufacture of Ammonia - The Haber Process

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

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

Various dilute acids, Methyl orange, Oxygen supply, Platinum wire, Copper(II) oxide, Combustion apparatus, U-tube for collection
Haber process flow charts, Industrial diagrams, Catalyst samples, Economic analysis sheets

KLB Secondary Chemistry Form 3, Pages 138-140

NITROGEN AND ITS COMPOUNDS

Uses of Ammonia and Introduction to Nitrogenous Fertilizers

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

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

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

KLB Secondary Chemistry Form 3, Pages 141-144

NITROGEN AND ITS COMPOUNDS

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

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

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.
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.

Various fertilizer formulas, Scientific calculators, Laboratory preparation materials, Environmental impact data
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 141-144
KLB Secondary Chemistry Form 3, Pages 144-145

NITROGEN AND ITS COMPOUNDS

Reactions of Dilute Nitric(V) Acid with Metals

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

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

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

KLB Secondary Chemistry Form 3, Pages 147-150

NITROGEN AND ITS COMPOUNDS

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

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

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

Various carbonates and hydroxides, Dilute nitric acid, Lime water, Universal indicator, Test tubes

KLB Secondary Chemistry Form 3, Pages 147-150

NITROGEN AND ITS COMPOUNDS

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

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

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

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

KLB Secondary Chemistry Form 3, Pages 150-151

NITROGEN AND ITS COMPOUNDS

Action of Heat on Nitrates - Decomposition Patterns

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

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

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

KLB Secondary Chemistry Form 3, Pages 151-153

NITROGEN AND ITS COMPOUNDS

Test for Nitrates - Brown Ring Test

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
Comprehensive Problem Solving - Nitrogen Chemistry

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
Solve complex problems involving nitrogen compounds
Apply knowledge to industrial processes
Calculate yields and percentages in reactions
Analyze experimental data and results

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.
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.

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
Scientific calculators, Comprehensive problem sets, Industrial data sheets, Experimental result tables

KLB Secondary Chemistry Form 3, Pages 154-157
KLB Secondary Chemistry Form 3, Pages 119-157

NITROGEN AND ITS COMPOUNDS

Laboratory Practical Assessment - Nitrogen Compounds

By the end of the lesson, the learner should be able to:
Demonstrate practical skills in nitrogen chemistry
Perform qualitative analysis of nitrogen compounds
Apply safety procedures correctly
Interpret experimental observations accurately

Practical examination: Identify unknown nitrogen compounds using chemical tests. Prepare specified nitrogen compounds. Demonstrate proper laboratory techniques. Safety assessment. Written report on observations and conclusions.

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

KLB Secondary Chemistry Form 3, Pages 119-157

NITROGEN AND ITS COMPOUNDS

Industrial Applications and Economic Importance
Chapter Review and Integration

By the end of the lesson, the learner should be able to:
Evaluate economic importance of nitrogen industry
Analyze industrial production costs and benefits
Compare different manufacturing processes
Assess impact on agricultural productivity

Case study analysis: Haber process economics, fertilizer industry impact, nitric acid production costs. Agricultural benefits: Crop yield improvements, food security. Economic calculations: Production costs, profit margins, environmental costs. Global nitrogen cycle importance.

Economic data sheets, Industry case studies, Agricultural statistics, Cost-benefit analysis templates
Concept mapping materials, Comparison charts, Flow diagram templates, Integration worksheets

KLB Secondary Chemistry Form 3, Pages 119-157

SULPHUR AND ITS COMPOUNDS

Extraction of Sulphur
Allotropes of Sulphur
Physical Properties of Sulphur - Solubility

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
Powdered sulphur, Water, Benzene, Methylbenzene, Carbon(IV) sulphide, Test tubes, Charts showing molecular structure

KLB Secondary Chemistry Form 4, Pages 160-161

SULPHUR AND ITS COMPOUNDS

Physical Properties of Sulphur - Effect of Heat
Chemical Properties of Sulphur - Reactions with Elements
Chemical Properties of Sulphur - Reactions with Acids
Uses of Sulphur and Introduction to Oxides
Preparation of Sulphur(IV) Oxide

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

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
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 164-165
KLB Secondary Chemistry Form 4, Pages 167-168

SULPHUR AND ITS COMPOUNDS

Physical and Chemical Properties of Sulphur(IV) Oxide
Bleaching Action of Sulphur(IV) Oxide

By the end of the lesson, the learner should be able to:
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
Colored flower petals (red/blue), SO2 gas jars, Hand lens for observation, Charts comparing bleaching agents

KLB Secondary Chemistry Form 4, Pages 171-173

SULPHUR AND ITS COMPOUNDS

Reducing Action of Sulphur(IV) Oxide

By the end of the lesson, the learner should be able to:
Investigate SO2 as a reducing agent. Test reactions with various oxidizing agents. Write ionic equations for redox reactions. Identify color changes in redox reactions.

Practical work: Experiment 7 - Testing SO2 with acidified potassium dichromate(VI), potassium manganate(VII), bromine water, iron(III) chloride. Recording observations in Table 6. Color changes: Orange to green, purple to colorless, brown to colorless, yellow to pale green. Writing half-equations and overall equations.

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

KLB Secondary Chemistry Form 4, Pages 173-176

SULPHUR AND ITS COMPOUNDS

Oxidising Action of Sulphur(IV) Oxide

By the end of the lesson, the learner should be able to:
Investigate SO2 as an oxidizing agent. Demonstrate reaction with stronger reducing agents. Explain the dual nature of SO Write equations for oxidation reactions by SO

Practical work: Experiment 8 - Lowering burning magnesium into SO2 gas. Observation: Continued burning, white fumes of MgO, yellow specks of sulphur. Reaction with hydrogen sulphide gas (demonstration). Discussion: SO2 decomposition providing oxygen. Writing equations: 2Mg + SO2 → 2MgO + S.

SO2 gas jars, Magnesium ribbon, Deflagrating spoon, Hydrogen sulphide gas, Water droppers, Safety equipment

KLB Secondary Chemistry Form 4, Pages 176-177

SULPHUR AND ITS COMPOUNDS

Test for Sulphate and Sulphite Ions & Uses of SO2
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:
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.
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.

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.
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.

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

KLB Secondary Chemistry Form 4, Pages 178-179
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

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

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

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

KLB Secondary Chemistry Form 4, Pages 184

SULPHUR AND ITS COMPOUNDS

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

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
Sodium carbonate, Zinc carbonate, Calcium carbonate, Copper(II) carbonate, Dilute H2SO4, Lime water, Test tubes

KLB Secondary Chemistry Form 4, Pages 184-185

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.
Describe laboratory preparation of hydrogen sulphide. Set up apparatus for H2S preparation. State the physical properties of H2S. Explain the toxicity and safety precautions.

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.
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.

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
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.

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
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

GAS LAWS

Boyle's Law - Introduction and Experimental Investigation
Boyle's Law - Mathematical Expression and Graphical Representation
Boyle's Law - Numerical Problems and Applications

By the end of the lesson, the learner should be able to:
State Boyle's law
Explain Boyle's law using kinetic theory of matter
Investigate the relationship between pressure and volume of a fixed mass of gas
Plot graphs to illustrate Boyle's law

Teacher demonstration: Use bicycle pump to show volume-pressure relationship. Students observe force needed to compress gas. Q/A: Review kinetic theory. Class experiment: Investigate pressure-volume relationship using syringes. Record observations in table format. Discuss observations using kinetic theory.

Bicycle pump, Syringes, Gas jars, Chart showing volume-pressure relationship
Graph papers, Scientific calculators, Chart showing mathematical expressions
Scientific calculators, Worked example charts, Unit conversion tables

KLB Secondary Chemistry Form 3, Pages 1-3

GAS LAWS

Charles's Law - Introduction and Temperature Scales
Charles's Law - Experimental Investigation and Mathematical Expression

By the end of the lesson, the learner should be able to:
State Charles's law
Convert temperatures between Celsius and Kelvin scales
Define absolute zero temperature
Explain the concept of absolute temperature

Teacher demonstration: Flask with colored water column experiment. Q/A: Observe volume changes with temperature. Exposition: Introduce Kelvin scale and absolute zero concept. Practice: Temperature conversions between °C and K. Discuss absolute zero and ideal gas concept.

Round-bottomed flask, Narrow glass tube, Colored water, Rubber bung, Hot and cold water baths
Glass apparatus, Thermometers, Graph papers, Water baths at different temperatures

KLB Secondary Chemistry Form 3, Pages 6-8

GAS LAWS

Charles's Law - Numerical Problems and Applications
Combined Gas Law and Standard Conditions
Introduction to Diffusion - Experimental Investigation
Rates of Diffusion - Comparative Study
Graham's Law of Diffusion - Theory and Mathematical Expression

By the end of the lesson, the learner should be able to:
Solve numerical problems using Charles's law
Apply V₁/T₁ = V₂/T₂ in calculations
Predict gas behavior with temperature changes
Relate Charles's law to everyday phenomena
Compare diffusion rates of different gases
Investigate factors affecting diffusion rates
Measure relative distances covered by diffusing gases
Calculate rates of diffusion using distance and time data

Worked examples: Step-by-step problem solving with temperature conversions. Supervised practice: Calculate volumes at different temperatures. Discuss applications: hot air balloons, tire pressure changes, weather balloons. Assignment: Practice problems with real-life contexts.
Class experiment: Ammonia and HCl diffusion in glass tube. Insert cotton wool soaked in concentrated NH₃ and HCl at opposite ends. Time the formation of white NH₄Cl ring. Measure distances covered by each gas. Calculate rates: distance/time. Compare molecular masses of NH₃ and HCl.

Scientific calculators, Temperature conversion charts, Application examples
Scientific calculators, Combined law derivation charts, Standard conditions reference table
KMnO₄ crystals, Bromine liquid, Gas jars, Combustion tube, Litmus papers, Stopwatch
Glass tube (25cm), Cotton wool, Concentrated NH₃ and HCl, Stopwatch, Ruler, Safety equipment
Graham's law charts, Molecular mass tables, Mathematical derivation displays

KLB Secondary Chemistry Form 3, Pages 10-12
KLB Secondary Chemistry Form 3, Pages 16-18

GAS LAWS

Graham's Law - Numerical Applications and Problem Solving

By the end of the lesson, the learner should be able to:
Solve numerical problems using Graham's law
Calculate relative rates of diffusion
Determine molecular masses from diffusion data
Compare diffusion times for equal volumes of gases

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

Scientific calculators, Worked example charts, Molecular mass reference tables

KLB Secondary Chemistry Form 3, Pages 20-22

THE MOLE

Relative Mass - Introduction and Experimental Investigation

By the end of the lesson, the learner should be able to:
Define relative mass using practical examples
Compare masses of different objects using a reference standard
Explain the concept of relative atomic mass
Identify carbon-12 as the reference standard

Experiment: Weighing different sized nails using beam balance. Use smallest nail as reference standard. Q/A: Discuss everyday examples of relative measurements. Teacher exposition: Introduction of carbon-12 scale and IUPAC recommendations. Calculate relative masses from experimental data.

Different sized nails ( 5-15cm), Beam balance, Fruits of different masses, Reference charts

KLB Secondary Chemistry Form 3, Pages 25-27

THE MOLE

Avogadro's Constant and the Mole Concept
Interconversion of Mass and Moles for Elements

By the end of the lesson, the learner should be able to:
Define Avogadro's constant and its value
Explain the concept of a mole as a counting unit
Relate molar mass to relative atomic mass
Calculate number of atoms in given masses of elements

Experiment: Determine number of nails with mass equal to relative mass in grams. Teacher exposition: Introduce Avogadro's constant (6.023 × 10²³). Discussion: Mole as counting unit like dozen. Worked examples: Calculate moles from mass and vice versa.

Beam balance, Various sized nails, Scientific calculators, Avogadro's constant charts
Scientific calculators, Periodic table, Worked example charts, Formula triangles

KLB Secondary Chemistry Form 3, Pages 27-30

THE MOLE

Molecules and Moles - Diatomic Elements
Empirical Formula - Experimental Determination

By the end of the lesson, the learner should be able to:
Distinguish between atoms and molecules
Define relative molecular mass
Calculate moles of molecules from given mass
Determine number of atoms in molecular compounds
Define empirical formula
Determine empirical formula from experimental data
Calculate mole ratios from mass data
Express results as simplest whole number ratios

Discussion: Elements existing as molecules (O₂, H₂, N₂, Cl₂). Teacher exposition: Difference between atomic and molecular mass. Worked examples: Calculate moles of molecular elements. Problem solving: Number of atoms in molecular compounds.
Experiment: Burning magnesium in air to form magnesium oxide. Measure masses before and after reaction. Calculate moles of Mg and O from mass data. Determine mole ratio and empirical formula. Safety precautions during heating.

Molecular models, Charts showing diatomic elements, Scientific calculators
Crucible and lid, Magnesium ribbon, Bunsen burner, Beam balance, Tongs, Safety equipment

KLB Secondary Chemistry Form 3, Pages 29-30
KLB Secondary Chemistry Form 3, Pages 32-35

THE MOLE

Empirical Formula - Reduction Method
Empirical Formula - Percentage Composition Method

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

Experiment: Reduction of copper(II) oxide using laboratory gas. Measure masses before and after reduction. Calculate moles of copper and oxygen. Determine empirical formula from mole ratios. Discuss experimental precautions.

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

KLB Secondary Chemistry Form 3, Pages 35-37

THE MOLE

Molecular Formula - Determination from Empirical Formula

By the end of the lesson, the learner should be able to:
Define molecular formula
Relate molecular formula to empirical formula
Calculate molecular formula using molecular mass
Apply the relationship (empirical formula)ₙ = molecular formula

Teacher exposition: Difference between empirical and molecular formulas. Worked examples: Calculate molecular formula from empirical formula and molecular mass. Formula: n = molecular mass/empirical formula mass. Practice problems with various organic compounds.

Scientific calculators, Molecular mass charts, Worked example displays

KLB Secondary Chemistry Form 3, Pages 38-40

THE MOLE

Molecular Formula - Combustion Analysis

By the end of the lesson, the learner should be able to:
Determine molecular formula from combustion data
Calculate moles of products in combustion
Relate product moles to reactant composition
Apply combustion analysis to hydrocarbons

Worked examples: Hydrocarbon combustion producing CO₂ and H₂O. Calculate moles of C and H from product masses. Determine empirical formula, then molecular formula. Practice: Various combustion analysis problems.

Scientific calculators, Combustion analysis charts, Molecular models of hydrocarbons

KLB Secondary Chemistry Form 3, Pages 40-41