ORGANIC CHEMISTRY II

Introduction to Alkanols and Nomenclature

By the end of the lesson, the learner should be able to:
Define alkanols and identify functional group
- Apply nomenclature rules for alkanols
- Draw structural formulae of simple alkanols
- Compare alkanols with corresponding alkanes

Q/A: Review alkanes, alkenes from Form 3
- Study functional group -OH concept
- Practice naming alkanols using IUPAC rules
- Complete Table 6.2 - alkanol structures

Molecular models, Table 6.1 and 6.2, alkanol structure charts, student books

KLB Secondary Chemistry Form 4, Pages 167-170

ORGANIC CHEMISTRY II

Isomerism in Alkanols
Laboratory Preparation of Ethanol

By the end of the lesson, the learner should be able to:
Explain positional and chain isomerism
- Draw isomers of given alkanols
- Name different isomeric forms
- Classify isomers as primary, secondary, or tertiary

Study positional isomerism examples (propan-1-ol vs propan-2-ol)
- Practice drawing chain isomers
- Exercises on isomer identification and naming
- Discussion on structural differences

Isomer structure charts, molecular models, practice worksheets, student books
Sugar, yeast, warm water, conical flask, delivery tube, lime water, thermometer

KLB Secondary Chemistry Form 4, Pages 170-171

ORGANIC CHEMISTRY II

Industrial Preparation and Physical Properties
Chemical Properties of Alkanols I
Chemical Properties of Alkanols II
Uses of Alkanols and Health Effects
Introduction to Alkanoic Acids

By the end of the lesson, the learner should be able to:
Explain hydration of ethene method
- Compare laboratory and industrial methods
- Analyze physical properties of alkanols
- Relate properties to molecular structure
State various uses of alkanols
- Explain health effects of alcohol consumption
- Discuss methylated spirits
- Analyze alcohol in society

Study ethene hydration using phosphoric acid catalyst
- Compare fermentation vs industrial methods
- Analyze Table 6.3 - physical properties
- Discussion on hydrogen bonding effects
Discussion on alkanol applications as solvents, fuels, antiseptics
- Health effects of alcohol consumption
- Methylated spirits composition
- Social implications

Table 6.3, industrial process diagrams, ethene structure models, property comparison charts
Ethanol, sodium metal, universal indicator, concentrated H₂SO₄, ethanoic acid, test tubes
Acidified potassium chromate/manganate, ethanoic acid, concentrated H₂SO₄, heating apparatus
Charts showing alkanol uses, health impact data, methylated spirit samples, discussion materials
Alkanoic acid structure charts, Table 6.5 and 6.6, molecular models, student books

KLB Secondary Chemistry Form 4, Pages 171-173
KLB Secondary Chemistry Form 4, Pages 176-177

ORGANIC CHEMISTRY II

Laboratory Preparation of Ethanoic Acid
Physical and Chemical Properties of Alkanoic Acids

By the end of the lesson, the learner should be able to:
Prepare ethanoic acid by oxidation
- Write equations for preparation
- Set up oxidation apparatus
- Identify product by testing

Experiment 6.3: Oxidize ethanol using acidified KMnO₄
- Set up heating and distillation apparatus
- Collect distillate at 118°C
- Test product properties

Ethanol, KMnO₄, concentrated H₂SO₄, distillation apparatus, thermometer, round-bottom flask
2M ethanoic acid, universal indicator, Mg strip, Na₂CO₃, NaOH, phenolphthalein, test tubes

KLB Secondary Chemistry Form 4, Pages 179-180

ORGANIC CHEMISTRY II

Esterification and Uses of Alkanoic Acids

By the end of the lesson, the learner should be able to:
Explain ester formation process
- Write esterification equations
- State uses of alkanoic acids
- Prepare simple esters

Complete esterification experiments
- Study concentrated H₂SO₄ as catalyst
- Write general esterification equation
- Discuss applications in food, drugs, synthetic fibres

Ethanoic acid, ethanol, concentrated H₂SO₄, test tubes, heating apparatus, cold water

KLB Secondary Chemistry Form 4, Pages 182-183

ORGANIC CHEMISTRY II

Introduction to Detergents and Soap Preparation

By the end of the lesson, the learner should be able to:
Define detergents and classify types
- Explain saponification process
- Prepare soap in laboratory
- Compare soapy and soapless detergents

Study soap vs soapless detergent differences
- Experiment 6.5: Saponify castor oil with NaOH
- Add salt for salting out
- Test soap formation

Castor oil, 4M NaOH, NaCl, evaporating dish, water bath, stirring rod, filter paper

KLB Secondary Chemistry Form 4, Pages 183-186

ORGANIC CHEMISTRY II

Mode of Action of Soap and Hard Water Effects
Soapless Detergents and Environmental Effects
Introduction to Polymers and Addition Polymerization

By the end of the lesson, the learner should be able to:
Explain soap molecule structure
- Describe cleaning mechanism
- Investigate hard water effects
- Compare soap performance in different waters
Explain soapless detergent preparation
- Compare advantages/disadvantages
- Discuss environmental impact
- Analyze pollution effects

Study hydrophobic and hydrophilic ends
- Demonstrate micelle formation
- Test soap in distilled vs hard water
- Observe scum formation
- Write precipitation equations
Study alkylbenzene sulphonate preparation
- Compare Table 6.9 - soap vs soapless
- Discussion on eutrophication and biodegradability
- Environmental awareness

Soap samples, distilled water, hard water (CaCl₂/MgSO₄ solutions), test tubes, demonstration materials
Flow charts of detergent manufacture, Table 6.9, environmental impact data, sample detergents
Polymer samples, monomer structure charts, molecular models, calculators, polymer formation diagrams

KLB Secondary Chemistry Form 4, Pages 186-188
KLB Secondary Chemistry Form 4, Pages 188-191

ORGANIC CHEMISTRY II

Addition Polymers - Types and Properties

By the end of the lesson, the learner should be able to:
Identify different addition polymers
- Draw structures from monomers
- Name common polymers
- Relate structure to properties

Study polystyrene, PTFE, perspex formation
- Practice identifying monomers from polymer structures
- Work through polymer calculation examples
- Properties analysis

Various polymer samples, structure identification exercises, calculation worksheets, Table 6.10

KLB Secondary Chemistry Form 4, Pages 195-197

ORGANIC CHEMISTRY II

Condensation Polymerization and Natural Polymers

By the end of the lesson, the learner should be able to:
Explain condensation polymerization
- Compare with addition polymerization
- Study natural polymers
- Analyze nylon formation

Study nylon 6,6 formation from diamine and dioic acid
- Natural polymers: starch, protein, rubber
- Vulcanization process
- Compare synthetic vs natural

Nylon samples, rubber samples, condensation reaction diagrams, natural polymer examples

KLB Secondary Chemistry Form 4, Pages 197-200

ORGANIC CHEMISTRY II

Polymer Properties and Applications
Comprehensive Problem Solving and Integration

By the end of the lesson, the learner should be able to:
Compare advantages and disadvantages of synthetic polymers
- State uses of different polymers
- Discuss environmental concerns
- Analyze polymer selection

Study Table 6.10 - polymer uses
- Advantages: strength, lightness, moldability
- Disadvantages: non-biodegradability, toxic gases
- Application analysis

Table 6.10, polymer application samples, environmental impact studies, product examples
Comprehensive problem sets, past examination papers, calculators, organic chemistry summary charts

KLB Secondary Chemistry Form 4, Pages 200-201

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Endothermic and Exothermic Reactions
Enthalpy Notation and Energy Content

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
- Define enthalpy and enthalpy change
-Use the symbol ΔH to represent enthalpy changes
-Calculate enthalpy changes using the formula ΔH = H(products) - H(reactants)
-Distinguish between positive and negative enthalpy changes

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.
Q/A: Review previous experiment results. Introduce enthalpy symbol H and enthalpy change ΔH. Calculate enthalpy changes from previous experiments. Explain why endothermic reactions have positive ΔH and exothermic reactions have negative ΔH. Practice calculations with worked examples.

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

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

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Bond Breaking and Bond Formation

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

Crushed pure ice, 250ml glass beakers, thermometers, heating source, stopwatch, graph paper, stirring rods

KLB Secondary Chemistry Form 4, Pages 32-35

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Latent Heat of Fusion and Vaporization
Bond Energy Calculations

By the end of the lesson, the learner should be able to:
- Define latent heat of fusion and molar heat of fusion
-Define latent heat of vaporization and molar heat of vaporization
-Explain why temperature remains constant during phase changes
-Relate intermolecular forces to melting and boiling points

Discussion based on previous heating curve experiment. Explain energy used to overcome intermolecular forces during melting and boiling. Compare molar heats of fusion and vaporization for water and ethanol. Relate strength of intermolecular forces to magnitude of latent heats. Calculate energy required for phase changes.

Data tables showing molar heats of fusion/vaporization, calculators, heating curves from previous lesson
Bond energy data tables, calculators, worked examples, practice problems

KLB Secondary Chemistry Form 4, Pages 32-35

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Determination of Enthalpy of Solution I

By the end of the lesson, the learner should be able to:
- Determine the enthalpy changes of solution of ammonium nitrate and sodium hydroxide
-Calculate enthalpy change using ΔH = mcΔT
-Calculate number of moles of solute dissolved
-Determine molar heat of solution

Class experiment: Dissolve exactly 2.0g NH₄NO₃ in 100ml distilled water in plastic beaker. Record temperature change. Repeat with 2.0g NaOH. Calculate enthalpy changes using ΔH = mcΔT where m = 100g, c = 4.2 kJ kg⁻¹K⁻¹. Calculate moles dissolved and molar heat of solution.

250ml plastic beakers, 2.0g samples of NH₄NO₃ and NaOH, distilled water, thermometers, measuring cylinders, analytical balance, calculators

KLB Secondary Chemistry Form 4, Pages 36-38

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Thermochemical Equations
Enthalpy of Solution of Concentrated Sulphuric Acid

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
- 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

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.
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.

Results from previous experiment, graph paper for energy level diagrams, practice examples
Concentrated H₂SO₄, distilled water, 250ml plastic beaker, tissue paper, measuring cylinders, thermometer, safety equipment

KLB Secondary Chemistry Form 4, Pages 38-39
KLB Secondary Chemistry Form 4, Pages 39-41

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Enthalpy of Combustion
Enthalpy of Displacement

By the end of the lesson, the learner should be able to:
- Define molar heat of combustion
-Determine enthalpy of combustion of ethanol experimentally
-Explain why experimental values differ from theoretical values
-Calculate molar enthalpy of combustion from experimental data

Class experiment: Burn ethanol in small bottle with wick to heat 100cm³ water in glass beaker. Record initial and final masses of bottle+ethanol and temperature change. Calculate moles of ethanol burned and heat evolved. Determine molar enthalpy of combustion. Compare with theoretical value (-1368 kJ/mol). Discuss sources of error.

Ethanol, small bottles with wicks, 250ml glass beakers, tripod stands, wire gauze, thermometers, analytical balance, measuring cylinders
Zinc powder, 0.5M CuSO₄ solution, 250ml plastic beakers, tissue paper, thermometers, analytical balance, stirring rods

KLB Secondary Chemistry Form 4, Pages 41-44

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Enthalpy of Neutralization

By the end of the lesson, the learner should be able to:
- Define molar heat of neutralization
-Determine heat of neutralization of HCl with NaOH
-Compare neutralization enthalpies of strong and weak acids/bases
-Write ionic equations for neutralization reactions

Class experiment: Mix 50cm³ of 2M HCl with 50cm³ of 2M NaOH in wrapped beaker. Record temperature changes. Calculate molar heat of neutralization. Repeat with weak acid (ethanoic) and weak base (ammonia). Compare values. Write ionic equations. Explain why strong acid + strong base gives ~57.2 kJ/mol.

2M HCl, 2M NaOH, 2M ethanoic acid, 2M ammonia solution, measuring cylinders, thermometers, 250ml plastic beakers, tissue paper

KLB Secondary Chemistry Form 4, Pages 47-49

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Standard Conditions and Standard Enthalpy Changes

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

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.

Student books, examples of standard enthalpy data, notation practice exercises

KLB Secondary Chemistry Form 4, Pages 49

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Hess's Law - Introduction and Theory
Energy Cycle Diagrams
Hess's Law Calculations

By the end of the lesson, the learner should be able to:
- State Hess's Law
-Explain the principle of energy conservation in chemical reactions
-Understand that enthalpy change is independent of reaction route
-Apply Hess's Law to simple examples
- 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

Introduce Hess's Law: "The energy change in converting reactants to products is the same regardless of the route by which the chemical change occurs." Use methane formation example to show two routes giving same overall energy change. Draw energy cycle diagrams. Explain law of conservation of energy application.
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.

Energy cycle diagrams for methane formation, chalkboard illustrations, worked examples from textbook
Graph paper, energy cycle templates, combustion data tables, calculators
Worked examples, combustion data, calculators, step-by-step calculation sheets

KLB Secondary Chemistry Form 4, Pages 49-52
KLB Secondary Chemistry Form 4, Pages 52-54

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Lattice Energy and Hydration Energy

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

Explain dissolution of NaCl: first lattice breaks (endothermic), then ions hydrate (exothermic). Define lattice energy as energy to form ionic solid 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.

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

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

KLB Secondary Chemistry Form 4, Pages 54-56

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Definition and Types of Fuels

By the end of the lesson, the learner should be able to:
- Define a fuel
-Classify fuels as solid, liquid, or gaseous
-State examples of each type of fuel
-Explain energy conversion in fuel combustion

Q/A: List fuels used at home and school. Define fuel as "substance that produces useful energy when it undergoes chemical or nuclear reaction." Classify examples: solids (coal, charcoal, wood), liquids (petrol, kerosene, diesel), gases (natural gas, biogas, LPG). Discuss energy conversions during combustion.

Examples of different fuels, classification charts, pictures of fuel types

KLB Secondary Chemistry Form 4, Pages 56

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Heating Values of Fuels
Factors in Fuel Selection
Environmental Effects of Fuels

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

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

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Fuel Safety and Precautions

By the end of the lesson, the learner should be able to:
- State precautions necessary when using fuels
-Explain safety measures for different fuel types
-Identify hazards associated with improper fuel handling
-Apply safety principles to local situations

Discuss safety precautions: ventilation for charcoal stoves (CO poisoning), not running engines in closed garages, proper gas cylinder storage, fuel storage away from populated areas, keeping away from fuel spills. Relate to local situations and accidents. Students identify potential hazards in their environment.

Safety guideline charts, examples of fuel accidents, local safety case studies

KLB Secondary Chemistry Form 4, Pages 57-58

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Endothermic and Exothermic Reactions
Bond Breaking, Formation and Phase Changes

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
Ice, glass beakers, thermometers, heating source, graph paper, bond energy data tables

KLB Secondary Chemistry Form 4, Pages 29-32

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Determination of Enthalpy of Solution

By the end of the lesson, the learner should be able to:
- Carry out experiments to determine enthalpy changes of solution
-Calculate enthalpy change using ΔH = mcΔT
-Write correct thermochemical equations
-Define molar heat of solution

Class experiment: Dissolve exactly 2.0g NH₄NO₃ and 2.0g NaOH separately in 100ml water. Record temperature changes. Calculate enthalpy changes using ΔH = mcΔT. Calculate moles and molar heat of solution. Write thermochemical equations: NH₄NO₃(s) + aq → NH₄NO₃(aq) ΔH = +25.2 kJ mol⁻¹.

2.0g samples of NH₄NO₃ and NaOH, plastic beakers, thermometers, analytical balance, calculators

KLB Secondary Chemistry Form 4, Pages 36-39

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
- Carry out experiments to determine enthalpy of combustion of ethanol
-Define molar heat of combustion
-Calculate molar enthalpy of combustion from experimental data
-Explain why actual heats are lower than 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.
Class experiment: Burn ethanol to heat 100cm³ water. Record mass of ethanol burned and temperature change. Calculate moles of ethanol and heat evolved using ΔH = mcΔT. Determine molar enthalpy of combustion. Compare with theoretical (-1368 kJ/mol). Discuss heat losses to surroundings.

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
KLB Secondary Chemistry Form 4, Pages 41-44

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Enthalpy of Displacement
Enthalpy of Neutralization

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

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.

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

KLB Secondary Chemistry Form 4, Pages 44-47

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Standard Conditions and Standard Enthalpy Changes

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

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.

Student books, standard enthalpy data examples, notation practice exercises

KLB Secondary Chemistry Form 4, Pages 49

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Hess's Law - Theory and Energy Cycles

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

KLB Secondary Chemistry Form 4, Pages 49-52

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Hess's Law Calculations
Lattice Energy and Hydration Energy
Definition and Types of Fuels

By the end of the lesson, the learner should be able to:
- Carry out calculations using Hess's Law
-Draw energy level diagrams
-Calculate enthalpy of formation from combustion data
-Solve worked examples using energy cycles
- 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

Work through ethanol formation: 2C(s) + 3H₂(g) + ½O₂(g) → C₂H₅OH(l). Draw energy cycle and level diagrams. Apply: ΔH°f(ethanol) = 2×ΔH°c(C) + 3×ΔH°c(H₂) - ΔH°c(ethanol) = 2×(-393) + 3×(-286) - (-1368) = -278 kJ/mol. Practice additional calculations from revision exercises.
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.

Worked examples, combustion data tables, graph paper for diagrams, calculators
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 52-56
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