ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Endothermic and Exothermic Reactions
Enthalpy Notation and Energy Content
Bond Breaking and Bond Formation
Latent Heat of Fusion and Vaporization

By the end of the lesson, the learner should be able to:
- Define endothermic and exothermic reactions using ΔH notation
-Investigate temperature changes when ammonium nitrate and sodium hydroxide dissolve in water
-Explain observations made during dissolution
-Draw energy level diagrams for endothermic and exothermic reactions
- Explain that energy changes are due to bond breaking and bond formation
-Describe bond breaking as endothermic and bond formation as exothermic
-Investigate energy changes during melting and boiling
-Plot heating curves for pure substances

Class experiment: Wrap 250ml plastic beakers with tissue paper. Dissolve 2 spatulafuls of NH₄NO₃ in 100ml distilled water, record temperature changes. Repeat with NaOH pellets. Compare initial and final temperatures. Draw energy level diagrams showing relative energies of reactants and products.
Class experiment: Heat crushed ice while stirring with thermometer. Record temperature every minute until ice melts completely, then continue until water boils. Plot temperature-time graph. Explain constant temperature during melting and boiling in terms of bond breaking. Discuss latent heat of fusion and vaporization.

250ml plastic beakers, tissue paper, rubber bands, NH₄NO₃, NaOH pellets, distilled water, thermometers, spatulas, measuring cylinders
Student books, calculators, worked examples from textbook, chalkboard for calculations
Crushed pure ice, 250ml glass beakers, thermometers, heating source, stopwatch, graph paper, stirring rods
Data tables showing molar heats of fusion/vaporization, calculators, heating curves from previous lesson

KLB Secondary Chemistry Form 4, Pages 29-31
KLB Secondary Chemistry Form 4, Pages 32-35

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Bond Energy Calculations
Determination of Enthalpy of Solution I

By the end of the lesson, the learner should be able to:
- Calculate energy changes in reactions using bond energies
-Apply the formula: Heat of reaction = Bond breaking energy + Bond formation energy
-Determine whether reactions are exothermic or endothermic
-Use bond energy data to solve problems

Work through formation of HCl from H₂ and Cl₂ using bond energies. Calculate energy required to break H-H and Cl-Cl bonds. Calculate energy released when H-Cl bonds form. Apply formula: ΔH = Energy absorbed - Energy released. Practice with additional examples. Discuss why calculated values may differ from experimental values.

Bond energy data tables, calculators, worked examples, practice problems
250ml plastic beakers, 2.0g samples of NH₄NO₃ and NaOH, distilled water, thermometers, measuring cylinders, analytical balance, calculators

KLB Secondary Chemistry Form 4, Pages 35-36

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Thermochemical Equations

By the end of the lesson, the learner should be able to:
- Write thermochemical equations including enthalpy changes
-Define molar heat of solution
-Draw energy level diagrams for dissolution reactions
-Interpret thermochemical equations correctly

Using data from previous experiment, write thermochemical equations for NH₄NO₃ and NaOH dissolution. Show proper notation with state symbols and ΔH values. Draw corresponding energy level diagrams. Practice writing thermochemical equations for various reactions. Explain significance of molar quantities in equations.

Results from previous experiment, graph paper for energy level diagrams, practice examples

KLB Secondary Chemistry Form 4, Pages 38-39

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Enthalpy of Solution of Concentrated Sulphuric Acid
Enthalpy of Combustion

By the end of the lesson, the learner should be able to:
- Determine heat of solution of concentrated sulphuric(VI) acid
-Apply safety precautions when handling concentrated acids
-Calculate enthalpy change considering density and purity
-Write thermochemical equation for the reaction

Teacher demonstration: Carefully add 2cm³ concentrated H₂SO₄ to 98cm³ distilled water in wrapped beaker (NEVER vice versa). Record temperature change. Calculate mass of acid using density (1.84 g/cm³) and purity (98%). Calculate molar heat of solution. Emphasize safety - always add acid to water.

Concentrated H₂SO₄, distilled water, 250ml plastic beaker, tissue paper, measuring cylinders, thermometer, safety equipment
Ethanol, small bottles with wicks, 250ml glass beakers, tripod stands, wire gauze, thermometers, analytical balance, measuring cylinders

KLB Secondary Chemistry Form 4, Pages 39-41

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Enthalpy of Displacement
Enthalpy of Neutralization
Standard Conditions and Standard Enthalpy Changes
Hess's Law - Introduction and Theory

By the end of the lesson, the learner should be able to:
- Define molar heat of displacement
-Investigate displacement of copper(II) ions by zinc
-Calculate molar heat of displacement
-Explain relationship between position in reactivity series and heat of displacement
- Identify standard conditions for measuring enthalpy changes
-Define standard enthalpy changes using ΔH° notation
-Explain importance of standard conditions
-Use subscripts to denote different types of enthalpy changes

Class experiment: Add 4.0g zinc powder to 100cm³ of 0.5M CuSO₄ solution in wrapped plastic beaker. Record temperature change and observations. Calculate moles of Zn used and Cu²⁺ displaced. Determine molar heat of displacement. Write ionic equation. Discuss why excess zinc is used. Compare with theoretical value.
Q/A: Review previous enthalpy measurements. Introduce standard conditions: 25°C (298K) and 1 atmosphere pressure (101.325 kPa). Explain ΔH° notation and subscripts (ΔH°c for combustion, ΔH°f for formation, etc.). Discuss why standard conditions are necessary for comparison. Practice using correct notation.

Zinc powder, 0.5M CuSO₄ solution, 250ml plastic beakers, tissue paper, thermometers, analytical balance, stirring rods
2M HCl, 2M NaOH, 2M ethanoic acid, 2M ammonia solution, measuring cylinders, thermometers, 250ml plastic beakers, tissue paper
Student books, examples of standard enthalpy data, notation practice exercises
Energy cycle diagrams for methane formation, chalkboard illustrations, worked examples from textbook

KLB Secondary Chemistry Form 4, Pages 44-47
KLB Secondary Chemistry Form 4, Pages 49

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Energy Cycle Diagrams

By the end of the lesson, the learner should be able to:
- Draw energy cycle diagrams
-Link enthalpy of formation with enthalpy of combustion
-Calculate unknown enthalpy changes using energy cycles
-Apply Hess's Law to determine enthalpy of formation

Work through energy cycle for formation of CO from carbon and oxygen using combustion data. Draw cycle showing Route 1 (direct combustion) and Route 2 (formation then combustion). Calculate ΔH°f(CO) = ΔH°c(C) - ΔH°c(CO). Practice with additional examples including ethanol formation.

Graph paper, energy cycle templates, combustion data tables, calculators

KLB Secondary Chemistry Form 4, Pages 52-54

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Hess's Law Calculations
Lattice Energy and Hydration Energy

By the end of the lesson, the learner should be able to:
- Solve complex problems using Hess's Law
-Apply energy cycles to multi-step reactions
-Calculate enthalpy of formation from combustion data
-Use thermochemical equations in Hess's Law problems

Work through detailed calculation for ethanol formation: 2C(s) + 3H₂(g) + ½O₂(g) → C₂H₅OH(l). Use combustion enthalpies of carbon (-393 kJ/mol), hydrogen (-286 kJ/mol), and ethanol (-1368 kJ/mol). Calculate ΔH°f(ethanol) = -278 kJ/mol. Practice with propane and other compounds.

Worked examples, combustion data, calculators, step-by-step calculation sheets
Energy cycle diagrams, lattice energy and hydration energy data tables, calculators

KLB Secondary Chemistry Form 4, Pages 54-56

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Factors Affecting Lattice and Hydration Energies
Definition and Types of Fuels

By the end of the lesson, the learner should be able to:
- Explain factors affecting lattice energy
-Explain factors affecting hydration energy
-Use data tables to identify trends
-Calculate enthalpies of solution for various ionic compounds

Analyze data tables showing lattice energies (Table 2.7) and hydration energies (Table 2.6). Identify trends: smaller ions and higher charges give larger lattice energies and hydration energies. Calculate heat of solution for MgCl₂ using: ΔH(solution) = +2489 + (-1891 + 2×(-384)) = -170 kJ/mol. Practice with other compounds.

Data tables from textbook, calculators, trend analysis exercises
Examples of different fuels, classification charts, pictures of fuel types

KLB Secondary Chemistry Form 4, Pages 54-56

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Heating Values of Fuels
Factors in Fuel Selection
Environmental Effects of Fuels
Fuel Safety and Precautions

By the end of the lesson, the learner should be able to:
- Define heating value of a fuel
-Calculate heating values from molar enthalpies of combustion
-Compare heating values of different fuels
-Explain units of heating value (kJ/g)
- Identify environmental effects of burning fuels
-Explain formation and effects of acid rain
-Describe contribution to global warming
-State measures to reduce pollution from fuels

Calculate heating value of ethanol: ΔH°c = -1360 kJ/mol, Molar mass = 46 g/mol, Heating value = 1360/46 = 30 kJ/g. Compare heating values from Table 2.8: methane (55 kJ/g), fuel oil (45 kJ/g), charcoal (33 kJ/g), wood (17 kJ/g). Discuss significance of these values for fuel selection.
Discuss pollutants from fossil fuels: SO₂, SO₃, CO, NO₂ causing acid rain. Effects: damage to buildings, corrosion, acidification of lakes, soil leaching. CO₂ and hydrocarbons cause global warming leading to ice melting, climate change. Pollution reduction measures: catalytic converters, unleaded petrol, zero emission vehicles, alternative fuels.

Heating value data table, calculators, fuel comparison charts
Fuel comparison tables, local fuel availability data, cost analysis sheets
Pictures of environmental damage, pollution data, examples of clean technology
Safety guideline charts, examples of fuel accidents, local safety case studies

KLB Secondary Chemistry Form 4, Pages 56-57
KLB Secondary Chemistry Form 4, Pages 57-58

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Endothermic and Exothermic Reactions

By the end of the lesson, the learner should be able to:
- Define endothermic and exothermic reactions using the ΔH notation
-Investigate what happens when ammonium nitrate and sodium hydroxide are separately dissolved in water
-Define enthalpy and enthalpy change
-Calculate enthalpy changes using ΔH = H(products) - H(reactants)

Class experiment: Dissolve NH₄NO₃ and NaOH separately in water, record temperature changes in Table 2.1. Explain heat absorption vs evolution. Introduce enthalpy (H) and enthalpy change (ΔH). Calculate enthalpy changes from experimental data. Draw energy level diagrams showing relative energies.

250ml plastic beakers, tissue paper, NH₄NO₃, NaOH pellets, distilled water, thermometers, calculators

KLB Secondary Chemistry Form 4, Pages 29-32

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Bond Breaking, Formation and Phase Changes
Determination of Enthalpy of Solution

By the end of the lesson, the learner should be able to:
- Explain that energy changes are due to bond breaking and bond formation
-Investigate energy changes when solids and liquids are heated
-Define latent heat of fusion and vaporization
-Calculate energy changes using bond energies

Class experiment: Heat ice to melting then boiling, record temperature every minute. Plot heating curve. Explain constant temperature periods. Define latent heat of fusion/vaporization. Calculate energy changes in H₂ + Cl₂ → 2HCl using bond energies. Apply formula: ΔH = Energy absorbed - Energy released.

Ice, glass beakers, thermometers, heating source, graph paper, bond energy data tables
2.0g samples of NH₄NO₃ and NaOH, plastic beakers, thermometers, analytical balance, calculators

KLB Secondary Chemistry Form 4, Pages 32-36

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Enthalpy of Solution of H₂SO₄ and Safety
Enthalpy of Combustion

By the end of the lesson, the learner should be able to:
- Determine heat of solution of concentrated sulphuric(VI) acid
-Apply safety precautions when handling concentrated acids
-Calculate enthalpy considering density and percentage purity
-Explain why experimental values differ from theoretical values

Teacher demonstration: Add 2cm³ concentrated H₂SO₄ to 98cm³ water (NEVER vice versa). Record temperature change. Calculate mass using density (1.84 g/cm³) and purity (98%). Calculate molar heat of solution. Emphasize safety: always add acid to water. Discuss sources of experimental error.

Concentrated H₂SO₄, distilled water, plastic beaker, tissue paper, thermometer, safety equipment
Ethanol, bottles with wicks, glass beakers, tripod stands, thermometers, analytical balance

KLB Secondary Chemistry Form 4, Pages 39-41

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Enthalpy of Displacement
Enthalpy of Neutralization
Standard Conditions and Standard Enthalpy Changes

By the end of the lesson, the learner should be able to:
- Investigate enthalpy change when zinc reacts with copper(II) sulphate
-Define molar heat of displacement
-Calculate molar heat of displacement from experimental data
-Explain relationship between reactivity series and heat evolved
- Define standard conditions for measuring enthalpy changes
-Use standard enthalpy notation ΔH°
-Apply correct notation for different types of enthalpy changes
-Explain importance of standardization for comparison

Class experiment: Add 4.0g zinc powder to 100cm³ of 0.5M CuSO₄. Record temperature change and observations (blue color fades, brown solid). Calculate moles and molar heat of displacement. Write ionic equation: Zn(s) + Cu²⁺(aq) → Zn²⁺(aq) + Cu(s). Explain why excess zinc is used.
Q/A: Review enthalpy measurements. Define standard conditions: 25°C (298K) and 1 atmosphere (101.325 kPa). Introduce ΔH° notation where θ denotes standard. Show subscripts: ΔH°c (combustion), ΔH°f (formation), ΔH°neut (neutralization), ΔH°sol (solution). Practice using correct notation in thermochemical equations.

Zinc powder, 0.5M CuSO₄ solution, plastic beakers, thermometers, analytical balance
2M HCl, 2M NaOH, 2M ethanoic acid, 2M ammonia solution, measuring cylinders, thermometers, plastic beakers
Student books, standard enthalpy data examples, notation practice exercises

KLB Secondary Chemistry Form 4, Pages 44-47
KLB Secondary Chemistry Form 4, Pages 49

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Hess's Law - Theory and Energy Cycles
Hess's Law Calculations

By the end of the lesson, the learner should be able to:
- State Hess's Law
-Explain that enthalpy change is independent of reaction route
-Draw energy cycle diagrams
-Apply Hess's Law to determine enthalpy of formation

Introduce Hess's Law: "Energy change in converting reactants to products is same regardless of route." Use methane formation showing Route 1 (direct combustion) vs Route 2 (formation then combustion). Draw energy cycle. Calculate ΔH°f(CH₄) = -965 + (-890) - (-75) = -75 kJ/mol. Practice with CO formation example.

Energy cycle diagrams for methane and CO formation, combustion data, calculators
Worked examples, combustion data tables, graph paper for diagrams, calculators

KLB Secondary Chemistry Form 4, Pages 49-52

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Lattice Energy and Hydration Energy
Definition and Types of Fuels

By the end of the lesson, the learner should be able to:
- Explain relationship between heat of solution, hydration and lattice energy
-Define lattice energy and hydration energy
-Draw energy cycles for dissolving ionic compounds
-Calculate heat of solution using energy cycles

Explain NaCl dissolution: lattice breaks (endothermic) then ions hydrate (exothermic). Define lattice energy as energy when ionic compound forms from gaseous ions. Define hydration energy as energy when gaseous ions become hydrated. Draw energy cycle: ΔH(solution) = ΔH(lattice) + ΔH(hydration). Calculate for NaCl: +781 + (-774) = +7 kJ/mol.

Energy cycle diagrams, hydration diagram (Fig 2.17), Tables 2.6 and 2.7 with lattice/hydration energies
Examples of local fuels, Table 2.8 showing heating values, calculators

KLB Secondary Chemistry Form 4, Pages 54-56

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Fuel Selection Factors
Environmental Effects and Safety

By the end of the lesson, the learner should be able to:
- State and explain factors that influence choice of a fuel
-Compare suitability of fuels for different purposes
-Explain fuel selection for domestic use vs specialized applications
-Apply selection criteria to local situations

Discuss seven factors: heating value, ease of combustion, availability, transportation, storage, environmental effects, cost. Compare wood/charcoal for domestic use (cheap, available, safe, slow burning) vs methylhydrazine for rockets (rapid burning, high heat 4740 kJ/mol, easy ignition). Students analyze best fuels for their local area.

Fuel comparison tables, local fuel cost data, examples of specialized fuel applications
Pictures of environmental damage, pollution reduction examples, safety guideline charts

KLB Secondary Chemistry Form 4, Pages 57

ELECTROCHEMISTRY

Redox Reactions and Oxidation Numbers
Oxidation Numbers in Naming and Redox Identification
Displacement Reactions - Metals and Halogens
Electrochemical Cells and Cell Diagrams
Standard Electrode Potentials
Calculating Cell EMF and Predicting Reactions
Types of Electrochemical Cells

By the end of the lesson, the learner should be able to:
Define redox reactions in terms of electron transfer
- State rules for assigning oxidation numbers
- Calculate oxidation numbers in compounds
- Identify oxidation and reduction processes
Define electrode potential and EMF
- Describe electrochemical cell components
- Draw cell diagrams using correct notation
- Explain electron flow and salt bridge function

Q/A: Review previous knowledge
- Experiment 4.1: Iron filings + copper(II) sulphate
- Experiment 4.2: Iron(II) ions + hydrogen peroxide
- Discussion on oxidation number rules with examples
Experiment 4.5: Set up Zn/Cu cell and other metal combinations
- Measure EMF values
- Practice writing cell notation
- Learn conventional representation methods

Iron filings, 1M CuSO₄, 1M FeSO₄, 2M NaOH, 20V H₂O₂, test tubes
Compound charts, calculators, student books, practice exercises
Various metals (Ca, Mg, Zn, Fe, Pb, Cu), metal salt solutions, halogens (Cl₂, Br₂, I₂), halide solutions
Metal electrodes, 1M metal salt solutions, voltmeters, salt bridges, connecting wires
Standard electrode potential table, diagrams, charts showing standard conditions
Calculators, electrode potential data, worked examples, practice problems
Cell diagrams, sample batteries, charts showing cell applications

KLB Secondary Chemistry Form 4, Pages 108-116
KLB Secondary Chemistry Form 4, Pages 123-128

ELECTROCHEMISTRY

Electrolysis of Aqueous Solutions I
Electrolysis of Aqueous Solutions II

By the end of the lesson, the learner should be able to:
Define electrolysis and preferential discharge
- Investigate electrolysis of dilute sodium chloride
- Compare dilute vs concentrated solution effects
- Test products formed

Experiment 4.6(a): Electrolysis of dilute NaCl
- Experiment 4.6(b): Electrolysis of brine
- Test gases evolved
- Compare results and explain differences

Dilute and concentrated NaCl solutions, carbon electrodes, gas collection tubes, test equipment
U-tube apparatus, 2M H₂SO₄, 0.5M MgSO₄, platinum/carbon electrodes, gas syringes

KLB Secondary Chemistry Form 4, Pages 141-146

ELECTROCHEMISTRY

Effect of Electrode Material on Electrolysis
Factors Affecting Electrolysis

By the end of the lesson, the learner should be able to:
Compare inert vs reactive electrodes
- Investigate electrode dissolution
- Explain electrode selection importance
- Analyze copper purification process

Experiment 4.9: Electrolysis of CuSO₄ with carbon vs copper electrodes
- Weigh electrodes before/after
- Observe color changes
- Discussion on electrode effects

Copper and carbon electrodes, 3M CuSO₄ solution, accurate balance, beakers, connecting wires
Electrochemical series chart, summary tables, practice exercises, student books

KLB Secondary Chemistry Form 4, Pages 141-148

ELECTROCHEMISTRY

Applications of Electrolysis I
Applications of Electrolysis II

By the end of the lesson, the learner should be able to:
Describe electrolytic extraction of reactive metals
- Explain electroplating process
- Apply electrolysis principles to metal coating
- Design electroplating setup

Discussion: Extraction of Na, Mg, Al by electrolysis
- Practical: Electroplate iron nail with copper
- Calculate plating requirements
- Industrial applications

Iron nails, copper electrodes, CuSO₄ solution, power supply, industrial process diagrams
Flow charts, mercury cell diagrams, environmental impact data, industrial case studies

KLB Secondary Chemistry Form 4, Pages 155-157

ELECTROCHEMISTRY

Faraday's Laws and Quantitative Electrolysis
Electrolysis Calculations I
Electrolysis Calculations II
Advanced Applications and Problem Solving

By the end of the lesson, the learner should be able to:
State Faraday's laws of electrolysis
- Define Faraday constant
- Calculate mass deposited in electrolysis
- Relate electricity to amount of substance
Determine charge on ions from electrolysis data
- Calculate current-time relationships
- Solve complex multi-step problems
- Apply concepts to industrial situations

Experiment 4.10: Quantitative electrolysis of CuSO₄
- Measure mass vs electricity passed
- Calculate Faraday constant
- Verify Faraday's laws
Complex problems: Determine ionic charges
- Current-time-mass relationships
- Multi-step calculations
- Industrial calculation examples

Accurate balance, copper electrodes, CuSO₄ solution, ammeter, timer, calculators
Calculators, worked examples, practice problems, gas volume data, Faraday constant
Calculators, complex problem sets, industrial data, student books
Past papers, comprehensive problem sets, industrial case studies, calculators

KLB Secondary Chemistry Form 4, Pages 161-164

METALS

Chief Ores of Metals and General Extraction Methods
Occurrence and Extraction of Sodium
Occurrence and Extraction of Aluminium I

By the end of the lesson, the learner should be able to:
Name chief ores of common metals
- State formulas of metal ores
- Explain general methods of ore concentration
- Describe factors affecting extraction methods

Q/A: Review metallic bonding and reactivity
- Study Table 5.1 - metal ores and formulas
- Discussion on ore concentration methods
- Froth flotation demonstration

Chart of metal ores, ore samples if available, Table 5.1, flotation apparatus demonstration
Down's cell diagram, charts showing sodium occurrence, electrode reaction equations
Bauxite samples, NaOH solution, charts showing aluminium extraction steps, chemical equations

KLB Secondary Chemistry Form 4, Pages 139-140

METALS

Extraction of Aluminium II - Electrolysis
Occurrence and Extraction of Iron
Extraction of Zinc
Extraction of Lead and Copper

By the end of the lesson, the learner should be able to:
Explain role of cryolite in aluminium extraction
- Describe electrolytic extraction process
- Write electrode equations
- Explain why anodes need replacement

Study Hall-Heroult process setup
- Analysis of electrolytic cell diagram
- Write electrode reactions
- Discussion on energy requirements and anode corrosion

Electrolytic cell diagram, cryolite samples, graphite electrodes, energy consumption data
Blast furnace diagram, iron ore samples, coke, limestone, temperature zone charts
Zinc ore samples, flow charts showing both methods, electrolytic cell diagrams
Lead and copper ore samples, extraction flow charts, electrolytic purification diagrams

KLB Secondary Chemistry Form 4, Pages 142-143

METALS

Physical Properties of Metals
Chemical Properties I - Reaction with Air

By the end of the lesson, the learner should be able to:
Compare physical properties of sodium, aluminium, zinc, iron and copper
- Explain metallic bonding effects
- Relate structure to properties
- Analyze property data

Study Table 5.2 - physical properties comparison
- Discussion on metallic bonding and electron sea model
- Analysis of melting points, conductivity, and density trends

Table 5.2, metal samples, conductivity apparatus, density measurement equipment
Deflagrating spoons, metal samples (Na, Al, Zn, Fe, Cu), Bunsen burners, safety equipment

KLB Secondary Chemistry Form 4, Pages 151-152

METALS

Chemical Properties II - Reaction with Water
Chemical Properties III - Reaction with Chlorine
Chemical Properties IV - Reaction with Acids
Uses of Metals I - Sodium and Aluminium

By the end of the lesson, the learner should be able to:
Test metal reactions with cold water and steam
- Arrange metals by reactivity
- Explain aluminium's apparent unreactivity
- Write chemical equations for reactions
Test metal reactions with dilute and concentrated acids
- Compare reaction patterns
- Write chemical equations
- Explain passivation effects

Experiment 5.2: Test metals with cold water and steam
- Use Table 5.4 for observations
- Test solutions with indicators
- Arrange metals in reactivity order
Experiment 5.4: Test metals with various acids - HCl, HNO₃, H₂SO₄
- Use Table 5.5 for systematic recording
- Observe gas evolution
- Discuss passivation

Metal samples, cold water, steam generator, test tubes, universal indicator, safety equipment
Chlorine gas, gas jars, metal samples, tongs, deflagrating spoons, fume cupboard, safety equipment
Various acids (dilute and concentrated), metal strips, test tubes, gas collection apparatus, safety equipment
Charts showing metal applications, alloy samples, aircraft parts, cooking vessels

KLB Secondary Chemistry Form 4, Pages 154-156
KLB Secondary Chemistry Form 4, Pages 157-158

METALS

Uses of Metals II - Zinc, Copper and Iron
Steel Types and Alloys

By the end of the lesson, the learner should be able to:
Explain galvanization process
- Describe copper electrical applications
- Compare iron, steel, and cast iron uses
- Analyze alloy compositions and properties

Study galvanization and rust prevention
- Copper in electrical applications
- Different types of steel and their compositions
- Alloy property comparisons

Galvanized sheets, copper wires, steel samples, alloy composition charts, brass and bronze samples
Steel samples with different compositions, carbon content charts, specialized tools, stainless steel items

KLB Secondary Chemistry Form 4, Pages 159-161

METALS

Environmental Effects of Metal Extraction

By the end of the lesson, the learner should be able to:
Identify environmental impacts of mining
- Explain pollution from metal extraction
- Describe waste management strategies
- Discuss NEMA regulations in Kenya

Analysis of mining environmental impact
- Air, water, and land pollution from extraction
- Waste management and slag utilization
- NEMA role and regulations

Environmental impact case studies, pollution images, NEMA regulation documents, waste management examples

KLB Secondary Chemistry Form 4, Pages 161-162