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.
Displacement reactions.

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.
Explain change of oxidation numbers during redox / displacement reactions. Arrange elements in order of their reducing power.

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.

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.

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

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

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.
Possibility of a reaction to take place.

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

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

Worked examples.
Oral exercise.
Assignment.

student book

K.L.B. BK IV
Pages 133-136
K.L.B. BK IV
Pages 136-137

ELECTRO-CHEMISTRY.

Primary and secondary chemical cells.

By the end of the lesson, the learner should be able to:
Describe the functioning of primary and secondary chemical cells.

Exposition of new concepts and brief discussion
Assignment.

student book

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.
Electrolysis of dilute sulphuric (VI) acid.

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

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

Brine voltameter.
Sulphuric acid voltameter.

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

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.
Name the chief ores of some metals.

Discuss above results, leading to Faraday?s law of electrolysis.
Worked examples.
Assignment.
Exposition and brief discussion.

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.
Occurrence and extraction of copper.

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

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

Flow chart: extraction of lead.
Flow chart: extraction of copper.

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

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 acids.

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

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.

Metals: Al, Zn, Fe, Cu.

Acids; HCl, HNO3, H2SO4.

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

METALS

Uses of metals.
Environmental effects of extraction of metals.

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

Q/A & brief discussion;
Uses of Sodium, Aluminium, Zinc, Iron and Copper & some alloys.
Oral questions and open discussion.
Assignment / Topic review.

student book

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

RADIOACTIVITY

Definition of radioactivity.
Alpha particles.
Equations involving alpha particles.

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


Define radioactivity, a nuclide and radioactive decay.
Differentiate between natural and artificial radioactivity.


State properties of alpha particles.
Describe methods of detecting alpha particles.
Write down and balance equations involving alpha particles.

Q/A: Review the atomic structure.
Exposition: symbolic representation of an atom / nucleus.
Exposition: meaning of radioactivity and radioactive decay.
Discussion: artificial and natural radioactivity.


Q/A: position of helium in the periodic table.
Expository approach:
Q/A: Review atomic and mass numbers.
Examples of balanced equations.
Supervised practice.

student book

K.L.B. BK IV
Pages 249-251
K.L.B. BK IV
Pages 251-253

RADIOACTIVITY

Beta particles. Gamma rays.
Radioactive Half-Life.

By the end of the lesson, the learner should be able to:
State properties of beta particles.
Define isotopes and isobars.
Write down balanced equations involving both alpha and beta particles.
State properties of gamma rays.
Define the term radioactive half-life. Solve problems relating to half ?life

Q/A: Review isotopes.
Expository approach: teacher briefly exposes new concepts.
Examples of equations.
Supervised practice.
Assignment.
Teacher demonstration: Dice experiment.
Exposition of the term half-life.
Worked examples.
Written exercise

student book
Dice.

K.L.B. BK IV
Pages 251-253

RADIOACTIVITY

Radioactive decay curve.
Nuclear fusion and nuclear fission. Applications of radioactivity.

By the end of the lesson, the learner should be able to:
Plot a radioactive decay curve to deduce the
half ?life from the curve.
Differentiate between nuclear fusion and nuclear fission.
Describe applications of radioactivity.

Drawing a radioactive decay curve inferring the half-life of the sample from the graph.
Exposition of new concepts accompanied by nuclear equations.
Brief discussion: Carbon dating, detecting leakage, medication, agriculture, industry; effect of static charges, etc.

Graph papers.
student book

K.L.B. BK IV
Pages 254-5