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

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
Various acids and bases from previous lessons, indicators, beakers, measuring cylinders, stirring rods

KLB Secondary Chemistry Form 4, Pages 3-5

ACIDS, BASES AND SALTS

Effect of Solvent on Acids
Effect of Solvent on Bases
Amphoteric Oxides and Hydroxides
Definition of Salts and Precipitation
Solubility of Chlorides, Sulphates and Sulphites

By the end of the lesson, the learner should be able to:
- Explain effect of polar and non-polar solvents on hydrogen chloride
-Investigate HCl behavior in water vs methylbenzene
-Define polar and non-polar solvents
-Explain why acids show properties only in polar solvents
- Define a salt as an ionic compound
-Define a precipitate
-Investigate precipitation reactions
-Write ionic equations showing formation of precipitates

Teacher demonstration: Dissolve HCl gas in water and methylbenzene separately. Test both solutions with litmus paper, magnesium, and calcium carbonate. Compare observations. Explain polarity of water vs methylbenzene. Discuss dissociation vs molecular solution.
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.

HCl gas, distilled water, methylbenzene, magnesium ribbon, calcium carbonate, litmus paper, test tubes, gas absorption apparatus
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
2M NaCl, 2M Na₂SO₄, 2M Na₂SO₃, 0.1M salt solutions, dilute HCl, test tubes, heating source

KLB Secondary Chemistry Form 4, Pages 7-9
KLB Secondary Chemistry Form 4, Pages 11-14

ACIDS, BASES AND SALTS

Complex Ions Formation
Solubility and Saturated Solutions

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
Saturated KNO₃ solution, evaporating dish, watch glass, measuring cylinder, thermometer, balance, heating source

KLB Secondary Chemistry Form 4, Pages 15-16

ACIDS, BASES AND SALTS

Effect of Temperature on Solubility

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

KClO₃, measuring cylinders, thermometer, burette, boiling tubes, heating source, graph paper

KLB Secondary Chemistry Form 4, Pages 18-20

ACIDS, BASES AND SALTS

Solubility Curves and Applications
Fractional Crystallization

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
Calculator, graph paper, data tables, worked examples from textbook

KLB Secondary Chemistry Form 4, Pages 20-21

ACIDS, BASES AND SALTS

Hardness of Water - Investigation
Types and Causes of Water Hardness
Effects of Hard Water
Methods of Removing Hardness I

By the end of the lesson, the learner should be able to:
- Determine the effects of various salt solutions on soap
-Identify cations that cause hardness
-Distinguish between hard and soft water
-Investigate effect of boiling on water hardness
- State disadvantages of hard water
-State advantages of hard water
-Explain formation of scum and fur
-Discuss economic and health implications

Class experiment: Test soap lathering with distilled water, tap water, rainwater, and solutions of MgCl₂, NaCl, Ca(NO₃)₂, CaHCO₃, NaHCO₃, ZnSO₄. Record volumes of soap needed. Boil some solutions and retest. Compare results and identify hardness-causing ions.
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.

Soap solution, burette, various salt solutions, conical flasks, distilled water, tap water, rainwater, heating source
Student books, examples from previous experiment, chalkboard for equations
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 22-24
KLB Secondary Chemistry Form 4, Pages 24-25

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

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

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.

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

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Bond Breaking and Bond Formation
Latent Heat of Fusion and Vaporization

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
Data tables showing molar heats of fusion/vaporization, calculators, heating curves from previous lesson

KLB Secondary Chemistry Form 4, Pages 32-35

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Bond Energy Calculations
Determination of Enthalpy of Solution I
Thermochemical Equations

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
- 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

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.
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.

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

KLB Secondary Chemistry Form 4, Pages 35-36
KLB Secondary Chemistry Form 4, Pages 36-38

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

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

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.

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

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:
- 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
Lattice Energy and Hydration Energy

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
- 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

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 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.

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
Energy cycle diagrams, lattice energy and hydration energy data tables, calculators

KLB Secondary Chemistry Form 4, Pages 49-52
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
Heating Values 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
Heating value data table, calculators, fuel comparison charts

KLB Secondary Chemistry Form 4, Pages 56

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Factors in Fuel Selection
Environmental Effects of Fuels

By the end of the lesson, the learner should be able to:
- State factors that influence choice of fuel
-Explain why different fuels are chosen for different purposes
-Compare advantages and disadvantages of various fuels
-Apply selection criteria to real situations

Discuss seven factors: heating value, ease of combustion, availability, transportation, storage, environmental effects, cost. Compare wood/charcoal for domestic use vs methylhydrazine for rockets. Analyze why each is suitable for its purpose. Students suggest best fuels for cooking, heating, transport in their area.

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 57

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Fuel Safety and Precautions
Endothermic and Exothermic Reactions
Bond Breaking, Formation and Phase Changes

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
- 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

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.
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.

Safety guideline charts, examples of fuel accidents, local safety case studies
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 57-58
KLB Secondary Chemistry Form 4, Pages 32-36

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Determination of Enthalpy of Solution
Enthalpy of Solution of H₂SO₄ and Safety

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
Concentrated H₂SO₄, distilled water, plastic beaker, tissue paper, thermometer, safety equipment

KLB Secondary Chemistry Form 4, Pages 36-39

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:
- 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

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.

Ethanol, bottles with wicks, glass beakers, tripod stands, thermometers, analytical balance
Zinc powder, 0.5M CuSO₄ solution, plastic beakers, thermometers, analytical balance

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:
- Determine heat of neutralization of HCl with NaOH
-Define molar heat of neutralization
-Compare strong acid/base with weak acid/base combinations
-Write ionic equations including enthalpy changes

Class experiment: Mix 50cm³ of 2M HCl with 50cm³ of 2M NaOH. Record temperatures and calculate molar heat of neutralization. Repeat with weak acid/base. Compare values: strong + strong ≈ 57.2 kJ/mol, weak combinations give lower values. Write H⁺(aq) + OH⁻(aq) → H₂O(l) ΔH = -57.2 kJ mol⁻¹.

2M HCl, 2M NaOH, 2M ethanoic acid, 2M ammonia solution, measuring cylinders, thermometers, plastic beakers

KLB Secondary Chemistry Form 4, Pages 47-49

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Standard Conditions and Standard Enthalpy Changes
Hess's Law - Theory and Energy Cycles
Hess's Law Calculations
Lattice Energy and Hydration Energy

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
- Carry out calculations using Hess's Law
-Draw energy level diagrams
-Calculate enthalpy of formation from combustion data
-Solve worked examples using energy cycles

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.
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.

Student books, standard enthalpy data examples, notation practice exercises
Energy cycle diagrams for methane and CO formation, combustion data, calculators
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

KLB Secondary Chemistry Form 4, Pages 49
KLB Secondary Chemistry Form 4, Pages 52-56

ENERGY CHANGES IN PHYSICAL AND CHEMICAL PROCESSES

Definition and Types of Fuels
Fuel Selection Factors
Environmental Effects and Safety

By the end of the lesson, the learner should be able to:
- Define a fuel
-Classify fuels into solid, liquid and gaseous types
-Define heating value of a fuel
-Calculate heating values from molar enthalpies of combustion

Define fuel as "substance producing useful energy in chemical/nuclear reaction." Classify: solids (coal, charcoal, wood), liquids (petrol, kerosene, diesel), gases (natural gas, biogas, LPG). Define heating value as "heat energy per unit mass." Calculate for ethanol: -1360 kJ/mol ÷ 46 g/mol = 30 kJ/g. Compare values from Table 2.8.

Examples of local fuels, Table 2.8 showing heating values, calculators
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 56-57