ACIDS, BASES AND SALTS

Definition of Acids

By the end of the lesson, the learner should be able to:
- Define an acid in terms of hydrogen ions
-Investigate reactions of magnesium and zinc carbonate with different acids
-Write equations for reactions taking place
-Explain why magnesium strip should be cleaned

Class experiment: React cleaned magnesium strips with 2M HCl, 2M ethanoic acid, 2M H₂SO₄, 2M ethanedioic acid. Record observations in table. Repeat using zinc carbonate. Write chemical equations. Discuss hydrogen ion displacement and gas evolution.

Magnesium strips, zinc carbonate, 2M HCl, 2M ethanoic acid, 2M H₂SO₄, 2M ethanedioic acid, test tubes, test tube rack

KLB Secondary Chemistry Form 4, Pages 1-3

ACIDS, BASES AND SALTS

Strength of Acids
Definition of Bases
Strength of Bases
Acid-Base Reactions
Effect of Solvent on Acids

By the end of the lesson, the learner should be able to:
- Compare strengths of acids using pH values
-Determine strengths of acids by comparing their electrical conductivity
-Classify acids as either strong or weak
-Explain complete and partial dissociation of acids
- Compare strengths of bases using pH values
-Determine strengths of bases by comparing their electrical conductivity
-Classify bases as either strong or weak
-Explain complete and partial ionization of bases

Class experiment: Test pH of 2M HCl and 2M ethanoic acid using universal indicator. Set up electrical conductivity apparatus with both acids. Record milliammeter readings. Compare results and explain in terms of hydrogen ion concentration. Discuss strong vs weak acid definitions.
Class experiment: Test pH of 2M NaOH and 2M ammonia solution using universal indicator. Test electrical conductivity of both solutions using same apparatus as acids. Compare deflections and pH values. Explain in terms of OH⁻ ion concentration and complete vs partial ionization.

2M HCl, 2M ethanoic acid, universal indicator, pH chart, electrical conductivity apparatus, milliammeter, carbon electrodes, beakers, wires
Calcium hydroxide, red litmus paper, phenolphthalein indicator, distilled water, test tubes, spatula, evaporating dish
2M NaOH, 2M ammonia solution, universal indicator, pH chart, electrical conductivity apparatus, milliammeter, carbon electrodes
Various acids and bases from previous lessons, indicators, beakers, measuring cylinders, stirring rods
HCl gas, distilled water, methylbenzene, magnesium ribbon, calcium carbonate, litmus paper, test tubes, gas absorption apparatus

KLB Secondary Chemistry Form 4, Pages 3-5
KLB Secondary Chemistry Form 4, Pages 5-7

ACIDS, BASES AND SALTS

Effect of Solvent on Bases
Amphoteric Oxides and Hydroxides

By the end of the lesson, the learner should be able to:
- Investigate effect of polar and non-polar solvents on ammonia gas
-Compare ammonia behavior in water vs methylbenzene
-Explain formation of ammonium hydroxide
-Write equations for ammonia dissolution in water

Class experiment: Test dry ammonia with dry litmus. Dissolve ammonia in water and test with litmus. Dissolve ammonia in methylbenzene and test with litmus. Record observations in table. Write equation for NH₃ + H₂O reaction. Explain why only aqueous ammonia shows basic properties.

Dry ammonia gas, distilled water, methylbenzene, red litmus paper, test tubes, gas collection apparatus
Al₂O₃, ZnO, PbO, Zn(OH)₂, Al(OH)₃, Pb(OH)₂, 2M HNO₃, 2M NaOH, boiling tubes, heating source

KLB Secondary Chemistry Form 4, Pages 9-10

ACIDS, BASES AND SALTS

Definition of Salts and Precipitation

By the end of the lesson, the learner should be able to:
- Define a salt as an ionic compound
-Define a precipitate
-Investigate precipitation reactions
-Write ionic equations showing formation of precipitates

Q/A: Review salt definition from Book 2. Demonstrate precipitation: Add sodium carbonate to solutions containing Mg²⁺, Ca²⁺, Zn²⁺, Al³⁺, Cu²⁺, Fe²⁺, Ba²⁺, Pb²⁺ ions. Record observations. Write ionic equations for precipitate formation. Explain why Fe³⁺ and Al³⁺ give different results.

Na₂CO₃ solution, salt solutions containing various metal ions, test tubes, droppers

KLB Secondary Chemistry Form 4, Pages 11-14

ACIDS, BASES AND SALTS

Solubility of Chlorides, Sulphates and Sulphites
Complex Ions Formation

By the end of the lesson, the learner should be able to:
- Find out cations that form insoluble chlorides, sulphates and sulphites
-Write ionic equations for formation of insoluble salts
-Distinguish between sulphate and sulphite precipitates
-Investigate effect of warming on precipitates

Class experiment: Add NaCl, Na₂SO₄, Na₂SO₃ to solutions of Pb²⁺, Ba²⁺, Mg²⁺, Ca²⁺, Zn²⁺, Cu²⁺, Fe²⁺, Fe³⁺, Al³⁺. Warm mixtures. Record observations in table. Test sulphite precipitates with dilute HCl. List soluble and insoluble salts.

2M NaCl, 2M Na₂SO₄, 2M Na₂SO₃, 0.1M salt solutions, dilute HCl, test tubes, heating source
2M NaOH, 2M NH₃ solution, 0.5M salt solutions, test tubes, droppers

KLB Secondary Chemistry Form 4, Pages 14-16

ACIDS, BASES AND SALTS

Solubility and Saturated Solutions
Effect of Temperature on Solubility

By the end of the lesson, the learner should be able to:
- Define the term solubility
-Determine solubility of a given salt at room temperature
-Calculate mass of solute and solvent
-Express solubility in different units
- Investigate the effect of temperature on solubility of potassium chlorate
-Record temperature at which crystals appear
-Calculate solubility at different temperatures
-Plot solubility curve

Class experiment: Weigh evaporating dish and watch glass. Measure 20cm³ saturated KNO₃ solution. Record temperature. Evaporate to dryness carefully. Calculate masses of solute, solvent, and solution. Determine solubility per 100g water and in moles per litre. Discuss definition and significance.
Class experiment: Dissolve 4g KClO₃ in 15cm³ water by warming. Cool while stirring and note crystallization temperature. Add 5cm³ water portions and repeat until total volume is 40cm³. Calculate solubility in g/100g water for each temperature. Plot solubility vs temperature graph.

Saturated KNO₃ solution, evaporating dish, watch glass, measuring cylinder, thermometer, balance, heating source
KClO₃, measuring cylinders, thermometer, burette, boiling tubes, heating source, graph paper

KLB Secondary Chemistry Form 4, Pages 16-18
KLB Secondary Chemistry Form 4, Pages 18-20

ACIDS, BASES AND SALTS

Solubility Curves and Applications

By the end of the lesson, the learner should be able to:
- Plot solubility curves for various salts
-Use solubility curves to determine mass of crystals formed
-Apply solubility curves to practical problems
-Compare solubility patterns of different salts

Using data from textbook, plot solubility curves for KNO₃, KClO₃, NaCl, CaSO₄. Calculate mass of crystals deposited when saturated solutions are cooled. Work through examples: KClO₃ cooled from 70°C to 30°C. Discuss applications in salt extraction and purification.

Graph paper, ruler, pencil, calculator, data tables from textbook

KLB Secondary Chemistry Form 4, Pages 20-21

ACIDS, BASES AND SALTS

Fractional Crystallization
Hardness of Water - Investigation

By the end of the lesson, the learner should be able to:
- Define fractional crystallization
-Apply knowledge of solubility curves in separation of salts
-Calculate masses of salts that crystallize
-Explain separation of salt mixtures

Work through separation problems using solubility data for KNO₃ and KClO₃ mixtures. Calculate which salt crystallizes first when cooled from 50°C to 20°C. Plot combined solubility curves. Discuss applications in Lake Magadi and Ngomeni salt works. Solve practice problems.

Calculator, graph paper, data tables, worked examples from textbook
Soap solution, burette, various salt solutions, conical flasks, distilled water, tap water, rainwater, heating source

KLB Secondary Chemistry Form 4, Pages 21-22

ACIDS, BASES AND SALTS

Types and Causes of Water Hardness

By the end of the lesson, the learner should be able to:
- Define temporary and permanent hardness
-Explain causes of temporary hardness
-Explain causes of permanent hardness
-Write equations for decomposition of hydrogen carbonates

Q/A: Review previous experiment results. Explain temporary hardness caused by Ca(HCO₃)₂ and Mg(HCO₃)₂. Write decomposition equations when boiled. Explain permanent hardness caused by CaSO₄, MgSO₄, Ca(NO₃)₂, Mg(NO₃)₂. Discuss why permanent hardness cannot be removed by boiling.

Student books, examples from previous experiment, chalkboard for equations

KLB Secondary Chemistry Form 4, Pages 24-25

ACIDS, BASES AND SALTS

Effects of Hard Water
Methods of Removing Hardness I

By the end of the lesson, the learner should be able to:
- State disadvantages of hard water
-State advantages of hard water
-Explain formation of scum and fur
-Discuss economic and health implications
- Explain removal of hardness by boiling
-Explain removal by distillation
-Write equations for these processes
-Compare effectiveness of different methods

Discussion based on practical experience: Soap wastage, scum formation on clothes, fur in kettles and pipes, pipe bursting in boilers. Advantages: calcium for bones, protection of lead pipes, use in brewing. Show examples of fur deposits. Calculate economic costs of hard water in households.
Demonstrate boiling method: Boil hard water samples from previous experiments and test with soap. Write equations for Ca(HCO₃)₂ and Mg(HCO₃)₂ decomposition. Discuss distillation method using apparatus setup. Compare costs and effectiveness. Explain why boiling only removes temporary hardness.

Samples of fur deposits, pictures of scaled pipes, calculator for cost analysis
Hard water samples, heating source, soap solution, distillation apparatus diagram

KLB Secondary Chemistry Form 4, Pages 24-25
KLB Secondary Chemistry Form 4, Pages 25-26

ACIDS, BASES AND SALTS

Methods of Removing Hardness II

By the end of the lesson, the learner should be able to:
- Explain removal using sodium carbonate
-Describe ion exchange method
-Explain removal using calcium hydroxide and ammonia
-Write equations for all processes

Demonstrate addition of Na₂CO₃ to hard water - observe precipitation. Explain ion exchange using resin (NaX) showing Ca²⁺ + 2NaX → CaX₂ + 2Na⁺. Discuss regeneration with brine. Write equations for Ca(OH)₂ and NH₃ methods. Compare all methods for effectiveness and cost.

Na₂CO₃ solution, hard water samples, ion exchange resin diagram, Ca(OH)₂, NH₃ solution

KLB Secondary Chemistry Form 4, Pages 25-26

ORGANIC CHEMISTRY I

Introduction to Organic Chemistry and Hydrocarbons
Sources of Alkanes - Natural Gas, Biogas, and Crude Oil

By the end of the lesson, the learner should be able to:
Define organic chemistry and hydrocarbons
Explain why carbon forms many compounds
Classify hydrocarbons into alkanes, alkenes, and alkynes
Identify the bonding in carbon compounds

Teacher exposition: Definition of organic chemistry. Discussion: Unique properties of carbon - tetravalency, catenation, multiple bonding. Q/A: Examples of hydrocarbons in daily life. Introduction to three main groups of hydrocarbons.

Carbon models, Hydrocarbon structure charts, Molecular model kits
Biogas digester model/diagram, Natural gas composition charts, Organic waste samples

KLB Secondary Chemistry Form 3, Pages 86-87

ORGANIC CHEMISTRY I

Fractional Distillation of Crude Oil

By the end of the lesson, the learner should be able to:
Explain fractional distillation process
Perform fractional distillation of crude oil
Identify different fractions and their uses
Relate boiling points to molecular size

Experiment: Fractional distillation of crude oil using improvised column. Collect fractions at different temperatures (120°C intervals up to 350°C). Test fractions for appearance, flammability, and viscosity. Record observations and relate to molecular size.

Crude oil sample, Boiling tubes, High-temperature thermometer, Sand/porcelain chips, Bunsen burner, Test tubes

KLB Secondary Chemistry Form 3, Pages 87-89

ORGANIC CHEMISTRY I

Cracking of Alkanes - Thermal and Catalytic Methods

By the end of the lesson, the learner should be able to:
Define cracking of alkanes
Distinguish between thermal and catalytic cracking
Write equations for cracking reactions
Explain industrial importance of cracking

Teacher exposition: Definition and purpose of cracking. Discussion: Thermal vs catalytic cracking conditions. Worked examples: Cracking equations producing smaller alkanes, alkenes, and hydrogen. Q/A: Industrial applications and hydrogen production.

Cracking process diagrams, Chemical equation charts, Catalyst samples for demonstration

KLB Secondary Chemistry Form 3, Pages 89-90

ORGANIC CHEMISTRY I

Alkane Series and Homologous Series Concept

By the end of the lesson, the learner should be able to:
Define homologous series using alkanes
Write molecular formulas for first 10 alkanes
Identify characteristics of homologous series
Apply general formula CₙH₂ₙ₊₂ for alkanes

Teacher exposition: Homologous series definition and characteristics. Table completion: Names, molecular formulas, and structures of first 10 alkanes. Discussion: General formula application. Pattern recognition: Gradual change in physical properties.

Alkane series chart, Molecular formula worksheets, Periodic table

KLB Secondary Chemistry Form 3, Pages 90-92

ORGANIC CHEMISTRY I

Nomenclature of Alkanes - Straight Chain and Branched
Isomerism in Alkanes - Structural Isomers

By the end of the lesson, the learner should be able to:
Name straight-chain alkanes using IUPAC rules
Identify parent chains in branched alkanes
Name branched alkanes with substituent groups
Apply systematic naming rules correctly

Teacher demonstration: Step-by-step naming of branched alkanes. Rules application: Longest chain identification, numbering from nearest branch, substituent naming. Practice exercises: Various branched alkane structures. Group work: Name complex branched alkanes.

Structural formula charts, IUPAC naming rules poster, Molecular model kits
Molecular model kits, Isomerism charts, Structural formula worksheets

KLB Secondary Chemistry Form 3, Pages 90-92

ORGANIC CHEMISTRY I

Laboratory Preparation of Methane
Laboratory Preparation of Ethane

By the end of the lesson, the learner should be able to:
Describe laboratory preparation of methane
Perform methane preparation experiment safely
Test physical and chemical properties of methane
Write equation for methane preparation
Prepare ethane using sodium propanoate and soda lime
Compare preparation methods of methane and ethane
Test properties of ethane gas
Write general equation for alkane preparation

Experiment: Heat mixture of sodium ethanoate and soda lime. Collect methane gas over water. Tests: Color, smell, combustion, reaction with bromine in dark. Record observations in table format. Safety precautions during gas collection.
Experiment: Prepare ethane from sodium propanoate and soda lime. Compare with methane preparation method. Carry out similar tests as for methane. Discussion: General pattern for alkane preparation from sodium alkanoates.

Sodium ethanoate, Soda lime, Round-bottomed flask, Gas collection apparatus, Bromine water, Wooden splints
Sodium propanoate, Soda lime, Gas collection apparatus, Testing materials

KLB Secondary Chemistry Form 3, Pages 94-96

ORGANIC CHEMISTRY I

Physical Properties of Alkanes

By the end of the lesson, the learner should be able to:
Describe physical properties of alkanes
Explain trends in melting and boiling points
Relate molecular size to physical properties
Compare solubility in different solvents

Data analysis: Study table of physical properties of first 10 alkanes. Graph plotting: Boiling points vs number of carbon atoms. Discussion: Intermolecular forces and property trends. Q/A: Solubility patterns in polar and non-polar solvents.

Physical properties data tables, Graph paper, Calculators, Solubility demonstration materials

KLB Secondary Chemistry Form 3, Pages 96-97

ORGANIC CHEMISTRY I

Chemical Properties of Alkanes - Combustion and Substitution

By the end of the lesson, the learner should be able to:
Write equations for complete and incomplete combustion
Explain substitution reactions with halogens
Describe conditions for halogenation reactions
Name halogenated alkane products

Worked examples: Combustion equations for various alkanes. Teacher demonstration: Methane + bromine in sunlight (or simulation). Discussion: Free radical mechanism in substitution. Practice: Write equations for chlorination of methane.

Molecular models, Halogenation reaction charts, Chemical equation worksheets

KLB Secondary Chemistry Form 3, Pages 97-98

ORGANIC CHEMISTRY I

Uses of Alkanes in Industry and Daily Life
Introduction to Alkenes and Functional Groups

By the end of the lesson, the learner should be able to:
List major uses of different alkanes
Explain industrial applications of alkanes
Describe environmental considerations
Evaluate economic importance of alkanes

Discussion: Uses of gaseous alkanes as fuels. Teacher exposition: Industrial applications - carbon black, methanol production, hydrogen source. Q/A: Environmental impact and cleaner fuel initiatives. Assignment: Research local uses of alkane products.

Industrial application charts, Product samples, Environmental impact materials
Alkene series charts, Molecular models showing double bonds, Functional group posters

KLB Secondary Chemistry Form 3, Pages 98-100

ORGANIC CHEMISTRY I

Nomenclature of Alkenes
Isomerism in Alkenes - Branching and Positional

By the end of the lesson, the learner should be able to:
Apply IUPAC rules for naming alkenes
Number carbon chains to give lowest numbers to double bonds
Name branched alkenes with substituents
Distinguish position isomers of alkenes
Draw structural isomers of alkenes
Distinguish between branching and positional isomerism
Identify geometric isomers in alkenes
Predict isomer numbers for given molecular formulas

Teacher demonstration: Step-by-step naming of alkenes. Rules application: Longest chain with double bond, numbering from end nearest double bond. Practice exercises: Name various alkene structures. Group work: Complex branched alkenes with substituents.
Practical exercise: Draw all isomers of butene and pentene. Teacher exposition: Branching vs positional isomerism in alkenes. Model building: Use molecular models for isomer visualization. Discussion: Geometric isomerism introduction (basic level).

IUPAC naming charts for alkenes, Structural formula worksheets, Molecular model kits
Molecular model kits, Isomerism worksheets, Geometric isomer models

KLB Secondary Chemistry Form 3, Pages 101-102
KLB Secondary Chemistry Form 3, Pages 102

ORGANIC CHEMISTRY I

Laboratory Preparation of Ethene

By the end of the lesson, the learner should be able to:
Prepare ethene by dehydration of ethanol
Describe role of concentrated sulfuric acid
Set up apparatus safely for ethene preparation
Test physical and chemical properties of ethene

Experiment: Dehydration of ethanol using concentrated H₂SO₄ at 170°C. Use sand bath for controlled heating. Pass gas through NaOH to remove impurities. Tests: Bromine water, acidified KMnO₄, combustion. Safety precautions with concentrated acid.

Ethanol, Concentrated H₂SO₄, Round-bottomed flask, Sand bath, Gas collection apparatus, Testing solutions

KLB Secondary Chemistry Form 3, Pages 102-104

ORGANIC CHEMISTRY I

Alternative Preparation of Ethene and Physical Properties
Chemical Properties of Alkenes - Addition Reactions

By the end of the lesson, the learner should be able to:
Describe catalytic dehydration using aluminum oxide
Compare different preparation methods
List physical properties of ethene
Explain trends in alkene physical properties

Demonstration: Alternative method using Al₂O₃ catalyst. Comparison: Acid vs catalytic dehydration methods. Data analysis: Physical properties of alkenes table. Discussion: Property trends with increasing molecular size.

Aluminum oxide catalyst, Glass wool, Alternative apparatus setup, Physical properties charts
Addition reaction charts, Mechanism diagrams, Chemical equation worksheets

KLB Secondary Chemistry Form 3, Pages 102-104

ORGANIC CHEMISTRY I

Oxidation Reactions of Alkenes and Polymerization

By the end of the lesson, the learner should be able to:
Describe oxidation by KMnO₄ and K₂Cr₂O₇
Explain polymerization of ethene
Define monomers and polymers
Write equations for polymer formation

Demonstration: Decolorization of KMnO₄ by alkenes. Teacher exposition: Polymerization process and polymer formation. Examples: Ethene → polyethene formation. Discussion: Industrial importance of polymerization. Practice: Write polymerization equations.

Oxidizing agents for demonstration, Polymer samples, Polymerization charts, Monomer-polymer models

KLB Secondary Chemistry Form 3, Pages 107-108

ORGANIC CHEMISTRY I

Tests for Alkenes and Uses
Introduction to Alkynes and Triple Bond

By the end of the lesson, the learner should be able to:
Perform chemical tests to identify alkenes
Use bromine water and KMnO₄ as test reagents
List industrial and domestic uses of alkenes
Explain importance in plastic manufacture
Define alkynes and triple bond structure
Write general formula for alkynes (CₙH₂ₙ₋₂)
Identify first members of alkyne series
Compare degree of unsaturation in hydrocarbons

Practical session: Test known alkenes with bromine water and acidified KMnO₄. Observe rapid decolorization compared to alkanes. Discussion: Uses in plastics, ethanol production, fruit ripening, detergents. Assignment: Research alkene applications.
Teacher exposition: Alkynes definition and C≡C triple bond. Table study: First 6 members of alkyne series with structures. Discussion: Degrees of unsaturation - alkanes vs alkenes vs alkynes. Model demonstration: Triple bond representation.

Test alkenes, Bromine water, Acidified KMnO₄, Plastic samples, Uses reference charts
Alkyne series charts, Triple bond molecular models, Unsaturation comparison charts

KLB Secondary Chemistry Form 3, Pages 108-109
KLB Secondary Chemistry Form 3, Pages 109-110

ORGANIC CHEMISTRY I

Nomenclature and Isomerism in Alkynes

By the end of the lesson, the learner should be able to:
Apply IUPAC naming rules for alkynes
Name branched alkynes with substituents
Draw structural isomers of alkynes
Identify branching and positional isomerism

Teacher demonstration: Systematic naming of alkynes using -yne suffix. Practice exercises: Name various alkyne structures. Drawing exercise: Isomers of pentyne and hexyne. Group work: Complex branched alkynes with multiple substituents.

IUPAC naming rules for alkynes, Structural formula worksheets, Molecular model kits

KLB Secondary Chemistry Form 3, Pages 110-111

ORGANIC CHEMISTRY I

Laboratory Preparation of Ethyne
Physical and Chemical Properties of Alkynes

By the end of the lesson, the learner should be able to:
Prepare ethyne from calcium carbide and water
Set up gas collection apparatus safely
Test physical and chemical properties of ethyne
Write equation for ethyne preparation

Experiment: Calcium carbide + water reaction. Use sand layer for heat absorption. Collect ethyne over water. Tests: Color, smell, combustion, bromine water, acidified KMnO₄. Safety: Dry apparatus, controlled water addition.

Calcium carbide, Sand, Flat-bottomed flask, Dropping funnel, Gas collection apparatus, Testing solutions
Physical properties charts, Comparison tables, Combustion equation examples

KLB Secondary Chemistry Form 3, Pages 111-112

ORGANIC CHEMISTRY I

Addition Reactions of Alkynes and Chemical Tests
Uses of Alkynes and Industrial Applications

By the end of the lesson, the learner should be able to:
Write equations for halogenation of alkynes
Describe hydrogenation and hydrohalogenation
Compare reaction rates: alkynes vs alkenes
Perform chemical tests for alkynes

Worked examples: Two-step addition reactions of ethyne with Br₂, Cl₂, H₂. Discussion: Faster reaction rates in alkynes compared to alkenes. Practical session: Test alkynes with oxidizing agents. Comparison: Rate of decolorization vs alkenes.

Addition reaction charts, Chemical equation worksheets, Test solutions, Stopwatch for rate comparison
Industrial application charts, Welding equipment demonstration/video, Synthetic fiber samples

KLB Secondary Chemistry Form 3, Pages 113-115