ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Endothermic and Exothermic Reactions.

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






To differentiate between endothermic & exothermic reactions.

Investigate temperature changes in solution formation.

Obtain changes in temperature when ammonium nitrate and sodium hydroxide are dissolved in water, one at a time.

Ammonium nitrate,
Sodium hydroxide, thermometers.

K.L.B. BK IV
Pages 32-33

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Energy level diagrams.
Enthalpy Notation. Change of state.

By the end of the lesson, the learner should be able to:
Represent endothermic reactions with exothermic reactions with energy level diagrams.

Define the term enthalpy.
Distinguish positive enthalpy change from negative enthalpy change.

Determine the M.P/ B.P of a pure substance.

Probing questions on relative energies of reactants and products in endothermic and exothermic and endothermic reactions.
Q/A and brief discussion.
Class experiments: determine B.P of pure water/ M.P of naphthalene / ice.
Use experimental results to plot temperature-time graphs.
Explain the shape of the graphs.
Q/A: review kinetic theory of matter.
Apply the theory to explain the shape of the graph, and nature of bonding in substances.

student book
Ice, naphthalene, thermometers, graph papers.

K.L.B. BK IV
Pages 33-35
K.L.B. BK IV
Pages 35-39

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

CAT

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

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Molar heat of solution.

By the end of the lesson, the learner should be able to:
Determine molar heat of solution of given substances.

Dissolve known masses of ammonia nitrate / sodium hydroxide in known volumes of water.
Determine temperature changes.
Calculate molar heat of solution. Supervised practice.

Ammonia nitrate / sodium hydroxide, thermometers.

K.L.B. BK IV
Pages 40-41

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Molar heat of solution.

By the end of the lesson, the learner should be able to:
Determine molar heat of solution of given substances.

Dissolve known masses of ammonia nitrate / sodium hydroxide in known volumes of water.
Determine temperature changes.
Calculate molar heat of solution. Supervised practice.

Ammonia nitrate / sodium hydroxide, thermometers.

K.L.B. BK IV
Pages 40-41

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Molar heat of solution of H2SO4.
Enthalpy of combustion. Enthalpy of combustion.

By the end of the lesson, the learner should be able to:
Determine molar heat of solution of H2SO4.
Define the term enthalpy of combustion.
Determine the enthalpy of combustion of ethanol.
Explain why actual heats of combustion are usually lower than the theoretical values.

Dissolve some known volume of conc. H2SO4 in a given volume of water.
Note the change in temperature.
Work out the molar heat of solution of H2SO4.

Group experiments / teacher demonstration.

Obtain and record results.


Work out calculations.

Conc. H2SO4, thermometers.
Ethanol, distilled water, thermometer, clear wick, tripod stand and wire gauze.

K.L.B. BK IV
Pages 42-45
K.L.B. BK IV
Pages 45-48

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Enthalpy of combustion. Enthalpy of combustion.

By the end of the lesson, the learner should be able to:
Define the term enthalpy of combustion.
Determine the enthalpy of combustion of ethanol.
Explain why actual heats of combustion are usually lower than the theoretical values.

Group experiments / teacher demonstration.

Obtain and record results.


Work out calculations.

Ethanol, distilled water, thermometer, clear wick, tripod stand and wire gauze.

K.L.B. BK IV
Pages 45-48

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Molar heat of displacement of ions.

By the end of the lesson, the learner should be able to:
Define the term molar heat of solution of displacement of ions.
Determine the molar heat of solution of displacement of ions.

Group experiments/ teacher demonstration.
Note steady temperature of solutions formed when zinc/ iron / magnesium reacts with copper sulphate solution.
Work out the molar heat of displacement of a substance from a solution of its ions.

Zinc, iron, magnesium, copper sulphate solution.

K.L.B. BK IV
Pages 48-50

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Molar heat of displacement of ions.

By the end of the lesson, the learner should be able to:
Define the term molar heat of solution of displacement of ions.
Determine the molar heat of solution of displacement of ions.

Group experiments/ teacher demonstration.
Note steady temperature of solutions formed when zinc/ iron / magnesium reacts with copper sulphate solution.
Work out the molar heat of displacement of a substance from a solution of its ions.

Zinc, iron, magnesium, copper sulphate solution.

K.L.B. BK IV
Pages 48-50

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Molar heat of solution of neutralization.
Standard enthalpy changes.

By the end of the lesson, the learner should be able to:
Define the term neutralization.
Determine the molar heat of neutralization of HCl with NaOH.
Define the term standard enthalpy change.
Denote standard enthalpy change with the correct notation.

Class experiments:
Neutralize 2M HCl of known volume with a determined volume of 1M / 2M sodium hydroxide.
Note highest temperature of the solution.
Work out the molar heat of neutralization.
Solve other related problems.
Assignment.

Exposition & brief discussion.

2M HCl of known volume, 1M / 2M sodium hydroxide.
student book

K.L.B. BK IV
Pages 50-53
K.L.B. BK IV
Pages 54-56

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Hess?s Law.

By the end of the lesson, the learner should be able to:
State Hess?s law.

Solve problems related to Hess?s law.

Detailed discussion & guided discovery of the law.
Illustrations of energy cycles and energy levels leading to Hess?s law.
Worked examples.
Supervised practice
Written assignment.

student book

K.L.B. BK IV
Pages 56-57

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Heat of solution hydration energy and lattice energy.

By the end of the lesson, the learner should be able to:
Define the terms lattice energy and hydration energy.
Explain the relationship between heat of solution, hydration energy.
Solve related problems.

Exposition of new concepts.
Guided discovery of the relationship between heat solution hydration energy and lattice energy.
Worked examples.
Assignment.

student book

K.L.B. BK IV
Pages 60-64

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Heat of solution hydration energy and lattice energy.

By the end of the lesson, the learner should be able to:
Define the terms lattice energy and hydration energy.
Explain the relationship between heat of solution, hydration energy.
Solve related problems.

Exposition of new concepts.
Guided discovery of the relationship between heat solution hydration energy and lattice energy.
Worked examples.
Assignment.

student book

K.L.B. BK IV
Pages 60-64

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Heat values of fuels.
Environmental effects of fuels.

By the end of the lesson, the learner should be able to:
Define the term fuel.
Describe energy changes when a fuel undergoes combustion.
Outline factors considered when choosing a suitable fuel.

Outline some environmental effects of fuels.
Identify measures taken to reduce environmental
pollution.

Probing questions and brief discussion.
Q/A & open discussion.

student book

K.L.B. BK IV
Pages 64-66
K.L.B. BK IV
Pages 67-68

RATES OF REACTION & REVERSIBLE REACTIONS.

Effect of concentration on rate of a reaction

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





Explain the effects of change of concentration of reactants on a reaction.

Group experiments to investigate effect of concentration on rate of reaction using dil. HCl and magnesium ribbons.
Determine the time taken for reactions to be complete.
Calculation of concentration of HCl in moles per litre.
Discuss the observations and sketch illustrative graphs.

Portions of 2M HCl diluted with different volumes of water,
Stopwatches.

K.L.B. BK IV
Pages 73-74

RATES OF REACTION & REVERSIBLE REACTIONS.

Effect of time of reaction on the rate of reaction.

By the end of the lesson, the learner should be able to:
Explain how the rate or reaction changes as the reaction proceed

Group experiments: investigate volume of gas evolved when magnesium reacts with dilute HCl.
Collect evolved gas and sketch and illustrative graphs.
Discuss the results.

Magnesium ribbons, stopwatches, conical flask.
100cm3 0.5M HCl, syringes, stoppers, tubes and connectors.

K.L.B. BK IV
Pages 75-79

RATES OF REACTION & REVERSIBLE REACTIONS.

Effect of temperature of reactants on rate of reaction.

By the end of the lesson, the learner should be able to:
Explain the effect of temperature on rate of reaction.

Group experiments: investigate the effects of temperature on the rate of reaction of sodium thiosulphate with dilute HCl.
Sketch and interpret relevant graphs.
Discuss the collision theory and effects of activation energy.

Sodium thiosulphate heated at different temperatures, dilute HCl, stopwatches.
Graph papers.

K.L.B. BK IV
Pages 80-83

RATES OF REACTION & REVERSIBLE REACTIONS.

Effect of change in surface area of reactants on the rate of a reaction.
Effect of a suitable catalyst on the rate of a reaction
Effect of light on rate of specific reactions.

By the end of the lesson, the learner should be able to:
Explain the effect of change in surface area on the rate of a reaction.
Explain effects of a suitable catalyst on the rate of a reaction.

Group experiment/ teacher demonstration.

Compare reactions of marble chips with dilute HCl and that of marble chips powder with equally diluted HCl.

Collect evolved gas in each case.

Teacher asks probing questions related to the observations made.

Teacher demonstration: preparation and collection of oxygen gas without using a catalyst, then using manganese (IV) oxide as a catalyst.
Explain the results in terms of activation energy.

Marble chips, marble chips powder, syringes, conical flasks with stoppers, 1M HCl.
Hydrogen peroxide, manganese (IV) oxide.
Silver bromide.

K.L.B. BK IV
Pages 83-85
K.L.B. BK IV
Pages 85-88

RATES OF REACTION & REVERSIBLE REACTIONS.

Reversible reactions.

By the end of the lesson, the learner should be able to:
Write down equations for reversible reactions.

Q/A: review temporary and permanent changes.
Teacher demonstration: heating crystals of hydrated copper (II) sulphate, then ?hydrating? them.
Write the corresponding chemical equations.
Give further examples of reversible reactions.

Crystals of hydrated copper (II) sulphate.

K.L.B. BK IV
Pages 91-93

RATES OF REACTION & REVERSIBLE REACTIONS.

State of equilibrium in chemical reactions.

By the end of the lesson, the learner should be able to:
Define the term equilibrium as used in reversible reactions.
Write down equations of reversible reactions in a state of equilibrium.

Brief discussion, giving examples of chemical equations for reversible reactions.

student book

K.L.B. BK IV
Pages 94-95

RATES OF REACTION & REVERSIBLE REACTIONS.

Le Chatelier?s Principle.

By the end of the lesson, the learner should be able to:
State Le Chatelier?s Principle.

Investigate the effect of change of concentration of reactants on equilibrium.
Add 2M sodium hydroxide in steps to bromine water.
Make and record observations.
Discuss the results leading to
Le Chatelier?s Principle.

Add 2M sodium hydroxide,

K.L.B. BK IV
Pages 95-97

RATES OF REACTION & REVERSIBLE REACTIONS.

Effect of change of pressure and temperature on equilibrium shift.
The Haber Process.
The Contact Process.

By the end of the lesson, the learner should be able to:
Explain the effect of change of pressure & te,perature on equilibrium shift.
Explain how change of temperature and pressure affect rate of manufacture of sulphur (VI) acid.

Q/A: review kinetic theory of matter.
Q/A & discussion on effect of change of pressure / temperature on shifting of equilibrium; giving specific examples of chemical equations.
Written assignment.

Probing questions and brief discussion.

Assignment.

student book

K.L.B. BK IV
Pages 97-101
K.L.B. BK IV
Pages 103-104

ELECTRO-CHEMISTRY.

Redox reactions.

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


Describe redox reactions in terms of gain / loss of electrons.
Identify oxidizing / reducing agents involved in redox reactions.

Q/A: review cations, anions and charges.
Write down ionic half equations and identify reducing / oxidizing agents.

student book

K.L.B. BK IV
Pages 108-9

ELECTRO-CHEMISTRY.

Oxidizing Numbers.

By the end of the lesson, the learner should be able to:
Outline rules of assigning oxidation numbers.
Determine the oxidation numbers of an element in a given compound.
Explain the use of oxidation numbers in naming compounds.

Exposition and giving specific examples.
Work out oxidizing number of elements in given compounds.
Copy and complete a table of compounds containing elements that more than one oxidation number.

student book

K.L.B. BK IV
Pages 109-116

ELECTRO-CHEMISTRY.

Displacement reactions.

By the end of the lesson, the learner should be able to:
Explain change of oxidation numbers during redox / displacement reactions. Arrange elements in order of their reducing power.

Class standard experiments: reacting metals with solutions containing metal ions.
Taking note of reactions and those that do not take place; and tabulating the results.

Metals: Ca, Na, Zn, Fe, Pb, and Cu.
Solutions containing Ca2+, Mg2+, Zn2+, Fe2+.

K.L.B. BK IV
Pages 116-120

ELECTRO-CHEMISTRY.

The oxidizing power of an element.
Cell diagrams.

By the end of the lesson, the learner should be able to:
Arrange elements in order of their oxidizing power.
Define the terms electrode, potential and e.m.f. of an electrochemical cell.
Describe components of a cell diagram.
Draw cell diagrams using correct notations.

Teacher demonstration / group expts:
Adding halogens to solutions containing halide ions.
Tabulate the results.
Discuss the results and arrive at the oxidizing power series of halogens.

Teacher demonstration: Zinc/ copper cell.
Q/A & discussion: changes in oxidation numbers.
Exposition: cell diagram and deducing the direction of electron flow.

Halogens:
Cl2 (g),
Br2 (l),
I2 (s).

Halides:
KCl, KBr, KI.
Zinc/ copper cell.

K.L.B. BK IV
Pages 120-122
K.L.B. BK IV
Pages 123-128

ELECTRO-CHEMISTRY.

Standard Electrode Potentials.

By the end of the lesson, the learner should be able to:
Identify standard conditions for measuring electrode potentials.
Define the term standard electrode potential of a cell.
Write half reactions of electrochemical cells.

Descriptive and expository approaches: teacher exposes new concepts.

student book

K.L.B. BK IV
Pages 129-131

ELECTRO-CHEMISTRY.

Standard electrode potential series.

By the end of the lesson, the learner should be able to:
Recall the order of standard electrode potentials.
Compare oxidizing and reducing powers of substances.

Q/A: review reactivity series, oxidizing agent, reducing agent.
Exposition: the order of standard electrode potentials.
Discussion: oxidizing and reducing powers of substances.

student book

K.L.B. BK IV
Pages 131-133

ELECTRO-CHEMISTRY.

Emf of a cell.

By the end of the lesson, the learner should be able to:
Calculate emf of a cell using standard electrodes potentials.

Q/A: review half-cells.
Worked examples; supervised practice.
Assignment.

student book

K.L.B. BK IV
Pages 133-136

ELECTRO-CHEMISTRY.

Possibility of a reaction to take place.
Primary and secondary chemical cells.

By the end of the lesson, the learner should be able to:
Predict whether a reaction will take place or not using standard electrode potentials.


Describe the functioning of primary and secondary chemical cells.

Worked examples.
Oral exercise.
Assignment.
Exposition of new concepts and brief discussion
Assignment.

student book

K.L.B. BK IV
Pages 136-137
K.L.B. BK IV
Pages 138-141

ELECTRO-CHEMISTRY.

Electrolysis of dilute NaCl.

By the end of the lesson, the learner should be able to:
Define the term electrolysis.
Explain the concept of preferential discharge of ions.

Teacher demonstration: electrolysis of dilute sodium chloride with carbon electrodes.
Test for gases collected.
Write down equations of reactions at each electrode.
Discussion: preferential discharge of ions at electrodes.

Dilute sodium chloride voltameter.

K.L.B. BK IV
Pages 141-144

ELECTRO-CHEMISTRY.

Electrolysis of brine.

By the end of the lesson, the learner should be able to:
Identify products of electrolysis of brine.

Teacher demonstration/ group experiments.
Test for the products of electrolysis.
Write relevant equations.

Brine voltameter.

K.L.B. BK IV
Pages 144-146

ELECTRO-CHEMISTRY.

Electrolysis of dilute sulphuric (VI) acid.

By the end of the lesson, the learner should be able to:
Identify products of electrolysis of dilute sulphuric (VI) acid.

Teacher demonstration/ group experiments.
Test for the products of electrolysis.
Write relevant equations.

Sulphuric acid voltameter.

K.L.B. BK IV
Pages 146-148

ELECTRO-CHEMISTRY.

Factors affecting electrolysis.
Application of electrolysis.

By the end of the lesson, the learner should be able to:
Explain factors that affect electrolytic products discharged at electrodes.
Describe some applications of electrolysis.

Q/A: review the electrochemical series of elements.
Teacher writes down order of ease of discharge of ions at electrodes.
Discussion: other factors; giving suitable examples.

Probing questions and brief discussion on applications of electrolysis.
Practical assignment on electrolysis: electroplating an iron nail with a suitable metal.

student book
Suitable voltameter.

K.L.B. BK IV
Pages 153-5
K.L.B. BK IV
Pages 155-7

ELECTRO-CHEMISTRY.
METALS

Faraday?s law of electrolysis.
Ores of some metals.

By the end of the lesson, the learner should be able to:
State Faraday?s law of electrolysis.
Solve problems related to Faraday?s law of electrolysis.

Discuss above results, leading to Faraday?s law of electrolysis.

Worked examples.

Assignment.

Weighing balance, stop watch, copper sulphate voltameter.

K.L.B. BK IV
Pages 161-4

METALS

Occurrence and extraction of sodium.

By the end of the lesson, the learner should be able to:
Describe occurrence and extraction of sodium.

Oral questions on electrolysis and equations at electrodes.
Brief discussion on occurrence and extraction.

Chart: Down?s cell.

K.L.B. BK IV
Pages 170-171

METALS

Occurrence and extraction of aluminium.

By the end of the lesson, the learner should be able to:
Describe occurrence and extraction of aluminium.

Brief discussion.
Write relevant chemical equations.

student book

K.L.B. BK IV
Pages 171-3

METALS

Occurrence and extraction of iron.
Occurrence and extraction of zinc.

By the end of the lesson, the learner should be able to:
Describe occurrence and extraction of iron.
Describe occurrence and extraction of zinc by electrolysis and reduction methods.

Brief discussion.
Write relevant chemical equations.

Chart: Blast furnace.
Flow chart: extraction of Zinc.

K.L.B. BK IV
Pages 173-5
K.L.B. BK IV
Pages 175-9

METALS

Extraction of lead.

By the end of the lesson, the learner should be able to:
Explain how lead is extracted.

Q/A & brief discussion.
Write balanced chemical equations leading to extraction of lead.

Flow chart: extraction of lead.

K.L.B. BK IV
Pages 179-80

METALS

Occurrence and extraction of copper.

By the end of the lesson, the learner should be able to:
Describe extraction of copper.

Q/A & brief discussion.
Write balanced chemical equations leading to extraction of copper.

Flow chart: extraction of copper.

K.L.B. BK IV
Pages 181-183

METALS

Physical properties of some metals.

By the end of the lesson, the learner should be able to:
State general properties of metals.
Explain the difference in physical properties of metals.

Compare physical properties of some metals as summarized in a chart.
Q/A & discussion based on physical properties.

student book

K.L.B. BK IV
Pages 183-4

METALS

Reaction of metals with oxygen.

By the end of the lesson, the learner should be able to:
Explain effect of burning metals in air.

Teacher demonstration / Group experiments.
Burning some metals in air.
Write relevant equations.
Brief discussion.

Common lab. metals.

K.L.B. BK IV
Pages 184-6

METALS

Reaction of metals with cold water and steam.

By the end of the lesson, the learner should be able to:
Describe reaction of metals with cold water and steam.

Arrange the metals in order of reactivity with cold water and steam.

Class experiments:
Investigate reaction of some metals with cold water and steam.
Analyse the results.

Metals: Al, Zn, Fe, Cu.

K.L.B. BK IV
Pages 186-9

METALS

Reaction of metals with chlorine.

By the end of the lesson, the learner should be able to:
Describe the reaction of metals with chlorine.

Teacher demonstration in a fume cupboard / in the open.
Investigate reaction of metals with chorine
Write corresponding equations.

Metals: Al, Zn, Fe, Cu.

K.L.B. BK IV
Pages 189-191

METALS

Reaction of metals with chlorine.

By the end of the lesson, the learner should be able to:
Describe the reaction of metals with chlorine.

Teacher demonstration in a fume cupboard / in the open.
Investigate reaction of metals with chorine
Write corresponding equations.

Metals: Al, Zn, Fe, Cu.

K.L.B. BK IV
Pages 189-191

METALS

Reaction of metals with acids.
Uses of metals.

By the end of the lesson, the learner should be able to:
Describe and explain reaction of metals with acids.
State uses of some metals and alloys.

Group experiments: investigate reaction of metals with dilute acids.
Teacher demonstration: investigate reaction of metals with concentrated acids.
Discuss the observations made and write relevant chemical equations.

Q/A & brief discussion;
Uses of Sodium, Aluminium, Zinc, Iron and Copper & some alloys.

Metals: Al, Zn, Fe, Cu.

Acids; HCl, HNO3, H2SO4.
student book

K.L.B. BK IV
Pages 191-4
K.L.B. BK IV
Pages 194-7

METALS

Environmental effects of extraction of metals.

By the end of the lesson, the learner should be able to:
Identify some environmental effects of extraction of metals.

Oral questions and open discussion.

Assignment / Topic review.

student book

K.L.B. BK IV
Pages 197-8