CHLORINE AND ITS COMPOUNDS

Chemical Properties of Chlorine - Reaction with 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

KLB Secondary Chemistry Form 4, Pages 199-201

CHLORINE AND ITS COMPOUNDS

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

By the end of the lesson, the learner should be able to:
Investigate reactions of chlorine with non-metals. Demonstrate reaction with phosphorus and hydrogen. Write equations for non-metal chloride formation. Explain the vigorous nature of these reactions.

Practical work: Experiment 6.5 - Warming red phosphorus and lowering into chlorine. Demonstration: Burning hydrogen jet in chlorine. Observations: White fumes of phosphorus chlorides, hydrogen chloride formation. Writing equations: P4 + 6Cl2 → 4PCl3, H2 + Cl2 → 2HCl. Discussion: Formation of covalent chlorides.

Red phosphorus, Hydrogen gas, Chlorine gas, Deflagrating spoon, Gas jars, Bunsen burner, Safety equipment
Sodium sulphite solution, Barium nitrate, Lead nitrate, Hydrogen sulphide gas, Aqueous ammonia, Chlorine gas, Test tubes

KLB Secondary Chemistry Form 4, Pages 201

CHLORINE AND ITS COMPOUNDS

Reaction of Chlorine with Alkali Solutions
Oxidising Properties - Displacement Reactions
Test for Chloride Ions

By the end of the lesson, the learner should be able to:
Investigate reactions of chlorine with alkalis. Compare reactions with cold dilute and hot concentrated alkalis. Write equations for formation of chlorates and hypochlorites. Explain formation of bleaching powder.

Practical work: Experiment 6.7 - Bubbling chlorine through cold dilute NaOH and hot concentrated NaOH. Recording observations in Table 6. Formation of pale-yellow solution (cold) vs colorless solution (hot). Equations: 3Cl2 + 6NaOH → 5NaCl + NaClO3 + 3H2O (hot), Cl2 + 2NaOH → NaCl + NaClO + H2O (cold). Discussion: Industrial production of bleaching powder.

Sodium hydroxide solutions (dilute cold, concentrated hot), Chlorine gas, Beakers, Bunsen burner, Thermometer
Potassium bromide solution, Potassium iodide solution, Chlorine gas, Test tubes, Observation charts
Sodium chloride, Concentrated H2SO4, Lead(II) nitrate solution, Aqueous ammonia, Glass rod, Test tubes, Bunsen burner

KLB Secondary Chemistry Form 4, Pages 202-203

CHLORINE AND ITS COMPOUNDS

Uses of Chlorine and its Compounds

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

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

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

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

KLB Secondary Chemistry Form 4, Pages 211-212

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

ORGANIC CHEMISTRY I

Introduction to Organic Chemistry and Hydrocarbons

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

KLB Secondary Chemistry Form 3, Pages 86-87

ORGANIC CHEMISTRY I

Sources of Alkanes - Natural Gas, Biogas, and Crude Oil

By the end of the lesson, the learner should be able to:
Identify natural sources of alkanes
Describe composition of natural gas and biogas
Explain crude oil as major source of alkanes
Describe biogas digester and its operation

Discussion: Natural gas composition (80% methane). Explanation: Biogas formation from organic waste decomposition. Teacher demonstration: Biogas digester model/diagram. Q/A: Environmental benefits of biogas production.

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
Cracking of Alkanes - Thermal and Catalytic Methods

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

KLB Secondary Chemistry Form 3, Pages 87-89

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

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

KLB Secondary Chemistry Form 3, Pages 90-92

ORGANIC CHEMISTRY I

Isomerism in Alkanes - Structural Isomers

By the end of the lesson, the learner should be able to:
Define isomerism in alkanes
Draw structural isomers of butane and pentane
Distinguish between chain and positional isomerism
Predict number of isomers for given alkanes

Teacher exposition: Isomerism definition and types. Practical exercise: Draw all isomers of butane and pentane. Discussion: Physical property differences between isomers. Model building: Use molecular models to show isomeric structures.

Molecular model kits, Isomerism charts, Structural formula worksheets

KLB Secondary Chemistry Form 3, Pages 92-94

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

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.

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

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

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.

IUPAC naming charts for alkenes, Structural formula worksheets, Molecular model kits

KLB Secondary Chemistry Form 3, Pages 101-102

ORGANIC CHEMISTRY I

Isomerism in Alkenes - Branching and Positional

By the end of the lesson, the learner should be able to:
Draw structural isomers of alkenes
Distinguish between branching and positional isomerism
Identify geometric isomers in alkenes
Predict isomer numbers for given molecular formulas

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).

Molecular model kits, Isomerism worksheets, Geometric isomer models

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

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

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.

Test alkenes, Bromine water, Acidified KMnO₄, Plastic samples, Uses reference charts

KLB Secondary Chemistry Form 3, Pages 108-109

ORGANIC CHEMISTRY I

Introduction to Alkynes and Triple Bond

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

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.

Alkyne series charts, Triple bond molecular models, Unsaturation comparison charts

KLB Secondary Chemistry Form 3, Pages 109-110

ORGANIC CHEMISTRY I

Nomenclature and Isomerism in Alkynes
Laboratory Preparation of Ethyne

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
Calcium carbide, Sand, Flat-bottomed flask, Dropping funnel, Gas collection apparatus, Testing solutions

KLB Secondary Chemistry Form 3, Pages 110-111

ORGANIC CHEMISTRY I

Physical and Chemical Properties of Alkynes

By the end of the lesson, the learner should be able to:
Describe physical properties of alkynes
Compare alkyne properties with alkenes and alkanes
Write combustion equations for alkynes
Explain addition reactions of alkynes

Data analysis: Physical properties of alkynes table. Comparison: Alkynes vs alkenes vs alkanes properties. Worked examples: Combustion reactions of ethyne. Teacher exposition: Two-step addition reactions due to triple bond.

Physical properties charts, Comparison tables, Combustion equation examples

KLB Secondary Chemistry Form 3, Pages 112-113

ORGANIC CHEMISTRY I

Addition Reactions of Alkynes and Chemical Tests

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

KLB Secondary Chemistry Form 3, Pages 113-115

ORGANIC CHEMISTRY I
ACIDS, BASES AND SALTS

Uses of Alkynes and Industrial Applications
Definition of Acids

By the end of the lesson, the learner should be able to:
List industrial uses of alkynes
Explain oxy-acetylene welding applications
Describe use in synthetic fiber production
Evaluate importance as chemical starting materials

Discussion: Industrial applications of alkynes in adhesives, plastics, synthetic fibers. Teacher demonstration: Oxy-acetylene flame principles (or video). Q/A: Starting materials for chemical synthesis. Assignment: Research local industrial uses.

Industrial application charts, Welding equipment demonstration/video, Synthetic fiber samples
Magnesium strips, zinc carbonate, 2M HCl, 2M ethanoic acid, 2M H₂SO₄, 2M ethanedioic acid, test tubes, test tube rack

KLB Secondary Chemistry Form 3, Pages 115-116

ACIDS, BASES AND SALTS

Strength of Acids
Definition of Bases
Strength of Bases

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

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.

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

KLB Secondary Chemistry Form 4, Pages 3-5

ACIDS, BASES AND SALTS

Acid-Base Reactions
Effect of Solvent on Acids

By the end of the lesson, the learner should be able to:
- Write equations for acid-base reactions
-Explain neutralization process
-Identify products of acid-base reactions
-Demonstrate formation of salt and water

Q/A: Review acid and base definitions. Demonstrate neutralization reactions: HCl + NaOH, H₂SO₄ + Ca(OH)₂, HNO₃ + KOH. Write molecular and ionic equations. Explain H⁺ + OH⁻ → H₂O. Discuss salt formation. Use indicators to show neutralization point.

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 6-7

ACIDS, BASES AND SALTS

Effect of Solvent on Bases
Amphoteric Oxides and Hydroxides
Definition of Salts and Precipitation

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

KLB Secondary Chemistry Form 4, Pages 9-10

ACIDS, BASES AND SALTS

Solubility of Chlorides, Sulphates and Sulphites

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

KLB Secondary Chemistry Form 4, Pages 14-16

ACIDS, BASES AND SALTS

Complex Ions Formation

By the end of the lesson, the learner should be able to:
- Explain formation of complex ions
-Investigate reactions with excess sodium hydroxide and ammonia
-Identify metal ions that form complex ions
-Write equations for complex ion formation

Class experiment: Add NaOH dropwise then in excess to Mg²⁺, Ca²⁺, Zn²⁺, Al³⁺, Cu²⁺, Fe²⁺, Fe³⁺, Pb²⁺ solutions. Repeat with NH₃ solution. Record observations showing precipitate formation and dissolution. Write equations for complex ion formation: [Zn(OH)₄]²⁻, [Al(OH)₄]⁻, [Pb(OH)₄]²⁻, [Zn(NH₃)₄]²⁺, [Cu(NH₃)₄]²⁺.

2M NaOH, 2M NH₃ solution, 0.5M salt solutions, test tubes, droppers

KLB Secondary Chemistry Form 4, Pages 15-16