ELECTRO-CHEMISTRY.

Redox reactions.
Oxidizing Numbers.

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.

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.

Q/A: review cations, anions and charges.
Write down ionic half equations and identify reducing / oxidizing agents.
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 108-9
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.

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.

By the end of the lesson, the learner should be able to:
Arrange elements in order of their oxidizing power.

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.

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

Halides:
KCl, KBr, KI.

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

ELECTRO-CHEMISTRY.

Cell diagrams.
Standard Electrode Potentials.

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

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

Descriptive and expository approaches: teacher exposes new concepts.

Zinc/ copper cell.

student book

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

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 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.
Factors affecting electrolysis.

By the end of the lesson, the learner should be able to:
Identify products of electrolysis of dilute sulphuric (VI) acid.
Explain factors that affect electrolytic products discharged at electrodes.

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

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.

Sulphuric acid voltameter.
student book

K.L.B. BK IV
Pages 146-148
K.L.B. BK IV
Pages 153-5

ELECTRO-CHEMISTRY.

Application of electrolysis.

By the end of the lesson, the learner should be able to:
Describe some applications of electrolysis.

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

Suitable voltameter.

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

ELECTRO-CHEMISTRY.

Faraday?s law of electrolysis.

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

Ores of some metals.

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


Name the chief ores of some metals.

Exposition and brief discussion.

K.L.B. BK IV
Pages 168-9

METALS

Ores of some metals.
Occurrence and extraction of sodium.

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


Name the chief ores of some metals.


Describe occurrence and extraction of sodium.

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

Chart: Down?s cell.

K.L.B. BK IV
Pages 168-9
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.

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

Brief discussion.
Write relevant chemical equations.

Chart: Blast furnace.

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

METALS

Occurrence and extraction of zinc.

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

Brief discussion.
Write relevant chemical equations.

Flow chart: extraction of Zinc.

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

METALS

Occurrence and extraction of zinc.
Extraction of lead.

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

Explain how lead is extracted.

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

Flow chart: extraction of Zinc.
Flow chart: extraction of lead.

K.L.B. BK IV
Pages 175-9
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 oxygen.
Reaction of metals with cold water and steam.

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

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

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

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

Common lab. metals.
Metals: Al, Zn, Fe, Cu.

K.L.B. BK IV
Pages 184-6
K.L.B. BK IV
Pages 186-9

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

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.

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

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

student book

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