ACIDS, BASES AND SALTS.

Strength of acids. Acids in aqueous form.

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


Define an acid in terms of hydrogen ions.

Explain strength of acids in aqueous form in terms of number of hydrogen ions present.

Class experiments: investigate reactions of magnesium and zinc carbonate with different acids.
Make and record observations in tabular form.
Make deductions from the observations.
Write relevant chemical equations and ionic equations.
Detailed discussion leading to the definition of an acid and explanation of strength of an acid.

Magnesium strip, zinc carbonate,
2M HCl,
2M H2SO4,
2M ethanoic acid.

K.L.B. BK IV
Pages 1-4

ACIDS, BASES AND SALTS.

pH values of acids. Electrical conductivities of aqueous acids.
Definition of a base in terms of hydroxide ions.

By the end of the lesson, the learner should be able to:
Determine strength of acids using pH values.
Determine strengths of acids by comparing their electrical conductivities.
Classify acids as either strong or weak in terms of partial dissociations in aqueous solutions.
Define a base in terms of hydroxide ions.

Q/A: review determination of strength of acids using a litmus paper and pH scale.
Class / group experiments: record colour of universal indicator in
2M HCl and 2M ethanoic acid.
Set up voltameters of 2M HCl and 2M ethanoic acid in turns.
Record amounts of current .
Discuss the observations.
Write corresponding ionic equations.
Teacher demonstration:
Dissolve calcium hydroxide in water.
Carry out litmus test on the resulting solution.
Discuss the results; hence define a base in terms of hydroxide ions.

Universal
indicator,
2M HCl,
2M ethanoic acid,
dry cells,
carbon electrodes,
milli-ammeters,
wires, switches etc.
Red litmus paper, calcium hydroxide solid.

K.L.B. BK IV
Pages 4-6

ACIDS, BASES AND SALTS.

Neutralization reaction.

By the end of the lesson, the learner should be able to:
Determine the results of reaction of an acid and a base.

Add 1M HCl to an aqueous solution of Calcium hydroxide drop wise until colour, change of the universal indicator is noted.
Write ionic equation for the reaction.

1M HCl,
Calcium hydroxide,
universal indicator.

K.L.B. BK IV
Page 7

ACIDS, BASES AND SALTS.

Strength of bases.
Dissolving hydrogen chloride gas in water / methylbenzene.
Dissolving ammonia gas in water/ methylbenzene.

By the end of the lesson, the learner should be able to:
Compare strengths of bases using pH values and electrical conductivity.


Classify bases/ alkali as either strong or weak in terms of complete / partial ionization.


Define a polar and a non-polar solvent.
Investigate effect of a polar / non-polar solvent on ammonia gas.

Carry out pH tests of 2M NaOH and 2M ammonia solution using universal indicator solutions; and observe colour changes.

Carry out electrical conductivity tests of voltameters of the above solutions.

Discussion: relate number of hydroxide ions to pH values and electrical conductivity of bases.


Teacher demonstration:
Dissolving HCl gas in different solvents.
Discuss the observations.
Write down related balanced chemical equations.
Carry out litmus tests on the resulting solution.
Make observations and deductions thereof.

2M NaOH,
2M ammonia solution, universal indicator solutions, dry cells,
carbon electrodes,
milliammeters,
wires, switches etc

Ammonia gas,
Methylbenzene, hydrogen chloride gas.
Methylbenzene.

K.L.B. BK IV
Pages 7-9
K.L.B. BK IV
Pages 9-11

ACIDS, BASES AND SALTS.

Amphoteric oxides.

By the end of the lesson, the learner should be able to:
Define an amphoteric oxide.
Identify some amphoteric oxides.

Class experiment:
Carry out acid / base reactions with metal oxides.
Q/A: make deductions from the results.
Writing and balancing relevant equations.

2M Nitric acid
2M NaOH,
HNO3.
Amphoteric oxides.

K.L.B. BK IV
Pages 12-14

ACIDS, BASES AND SALTS.

Precipitation Reactions.

By the end of the lesson, the learner should be able to:
Define a precipitate.
Write ionic equations showing formation of precipitates.

Q/A: review definition of a salt.
Class experiment;
Add sodium carbonate or a suitable carbonate to various salt solutions containing Mg2+, Al3+, Ca2+, etc.
Make observations and discuss the results.

Soluble carbonates e.g. Na2CO3, K2CO3, (NH4)2CO3
Salt solutions containing Mg2+, Al3+, Ca2+, etc.

K.L.B. BK IV
Pages 14-16

ACIDS, BASES AND SALTS.

Solubility of chlorides sulphites and sulphates.
Equations for formation of insoluble chlorides, sulphites and sulphates.
Complex ions.

By the end of the lesson, the learner should be able to:
Find out cations that form (in)soluble chlorides, sulphates and sulphites.
Write down equations for formation of insoluble chlorides, sulphites and sulphates.
Explain formation of complex ions.

Class experiments: measure 2cc of 0.1M solution containing Pb2+ into a test tube.
Add drops of 2M NaCl solution.
(Later 2M Sodium Sulphate and 2M Sodium Sulphate).
Warm the mixture and make observations.
Repeat the procedure using other salt solutions containing other ions.
Tabulate the results.
Q/A: review observations made in the above experiments.
Discuss the solubility of the cations.
Write relevant ionic equations.
Add drops of 2M sodium hydroxide / 2M ammonia solution to a solution containing Mg2+, Zn2+, etc.

Make observations and discuss the results.

0.1M solution containing Pb2+, 2M NaCl solution, 2M sodium sulphate, source of heating.
student book
2M Sodium hydroxide (2M ammonia solution),
solution containing Mg2+, Zn2+, etc.

K.L.B. BK IV
Pages 16-17
K.L.B. BK IV
Pages 18-20

ACIDS, BASES AND SALTS.

Solubility of a salt at a given temperature.

By the end of the lesson, the learner should be able to:
Define the term solubility.
Determine solubility of a given salt at room temperature.

Q/A: review the terms saturated, unsaturated solutions & crystallization.
Class experiment: determine mass of a solute that dissolves in 100cc of water at room temperature.

Suitable solutes.

K.L.B. BK IV
Pages 20-21

ACIDS, BASES AND SALTS.

Problems solving on solubility.

By the end of the lesson, the learner should be able to:
Solve problems involving solubility of a solute in a solvent at a given temperature.

Worked examples.
Supervised practice.
Written assignment.

Evaporating dish, watch glass, heating source, thermometer.

K.L.B. BK IV
Pages 21-22

ACIDS, BASES AND SALTS.

Effect of temperature on solubility of a solute in a solvent.
Effects of various salts on soap.
Removal of hardness of water.

By the end of the lesson, the learner should be able to:
Investigate the effect of temperature on solubility of a solute in a solvent.
Determine the effects of various salts on soap.
Identify ions for hardness of water.
Identify methods of removing hardness of water.
State merits & demerits of hard water.

Experiments involving solubility of KClO3 at different temperatures.
Note temperatures at which crystallization occurs.
Oral questions and discussion.
Group experiments: form soap lather in distilled water, tap water, rainwater, dilute solution of sodium chloride and solutions containing Ca2+ and Zn2+.
Note volume of soap that forms lather readily.
Review results of above experiments.

Probing questions & brief discussion.

Assignment.

KClO3 thermometers, source of heat.
distilled water, tap water, rainwater, dilute solution of sodium chloride and solutions containing Ca2+ and Zn2+.
student book

K.L.B. BK IV
Pages 22-25
K.L.B. BK IV
Pages 27-29

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Alkanols (Alcohols).
Nomenclature of alkanols.

By the end of the lesson, the learner should be able to:
Identify the functional group of alkanols.
Explain formation of alkanol molecules.
Name and draw the structure of simple alkanols.

Q/A: review alkanes, alkenes and alkynes.
Teacher exposes new concepts and links them with already known concepts.
Guided discovery of naming system for alkanols.
Draw and name structures of alkanols.

student book

K.L.B. BK IV
Page 205

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Isomerism in alkanols.

By the end of the lesson, the learner should be able to:
Describe positional and chain isomerism in alkanols.
Explain formation of primary and secondary alkanols.

Q/A: review the terms positional and chain isomerism.
Brief discussion on isomerism.
Oral exercise: naming given organic compounds.
Written exercise: writing structural formulae for isomers of organic compounds of a given molecular formula.

student book

K.L.B. BK IV
Pages 208-10

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Preparation of ethanol in the lab.
Physical properties of alkanols.
Chemical properties of alkanols.

By the end of the lesson, the learner should be able to:
Describe preparation of ethanol in the laboratory.
Explain the physical properties of alkanols.
Describe some chemical reactions of alkanols.

Group experiments / teacher demonstration.

Discuss the fermentation process.
Comparative evaluation of physical properties of alkanols.
Q/A & discussion on variation in physical properties of alkanols.
Group experiments/ teacher demonstration to investigate combustion of ethanol and its reaction with metals.
Write corresponding chemical equations.

Calcium hydroxide solution, sugar solution, yeast.


student book

K.L.B. BK IV
Pages 210-11
K.L.B. BK IV
Page 212

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Esters and esterification.

By the end of the lesson, the learner should be able to:
Explain formation of esters.
Describe the esterification process.

Teacher exposes and explains new concepts.

Assignment.

student book

K.L.B. BK IV
Pages 215-6

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Oxidation of ethanol. Uses of alkanols.
Alkanoic (Carboxylic Acids).

By the end of the lesson, the learner should be able to:
Explain oxidation of ethanol by an oxidizing agent.
State uses of alkanols.
Explain the effects of alcohol on human health
Identify the functional group of alkanoic (carboxylic) acids.
Explain formation of alkanoic acid molecule.

Q/A: review redox reactions, oxidizing and reducing agents.
Brief discussion: oxidation of ethanol using potassium (VII) manganate or potassium (VI) dichromate.
Write corresponding chemical equations.
Open discussion.
Q/A: review functional group of alkanols.
Brief discussion.

student book

K.L.B. BK IV
Pages 216-8

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Nomenclature of alkanoic acids.
Lab preparation of ethanoic acid.

By the end of the lesson, the learner should be able to:
Name and draw the structure of simple alkanoic acids.


Describe laboratory preparation of ethanoic acid.

Guided discovery of the naming system for alkanoic acids.
Teacher demonstration: prepare ethanoic acid in the lab.

Brief discussion on preparation of ethanoic acid.

Chart: homologous series of alkanoic acids.
Concentrated H2SO4, potassium manganate
(VII) Crystals, water bath.

K.L.B. BK IV
Pages 219-221
K.L.B. BK IV
Pages 221-223

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Physical properties of alkanoic acids.
Chemical properties of alkanoic acids.

By the end of the lesson, the learner should be able to:
Explain some physical properties of alkanoic acids.
Explain some chemical properties of alkanoic acids.

Compare physical properties of some alkanoic acids.
Discuss the difference in physical properties among alkanoic acids.
Group experiment: investigate some chemical properties of ethanoic acid.
Carry out tests and record observations in a table.

student book
Ethanoic acid, universal indicator, sodium carbonate, magnesium strip, ethanol, conc. H2SO4 and sodium hydroxide.

K.L.B. BK IV
Pages 223-4

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Chemical properties & Uses of alkanoic acids.

By the end of the lesson, the learner should be able to:
Write equations for chemical reactions involving acids.
State uses of alkanoic acids.

Review and discuss the observations above.
Write corresponding chemical equations.
Teacher elucidates uses of alkanoic acids.

student book

K.L.B. BK IV
Pages 225-7

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Soap preparation in the lab.
Cleaning action of soap.
Effects of hard / soft water on soap.

By the end of the lesson, the learner should be able to:
Describe soap preparation in the lab.
Describe the nature of a soap molecule.
Explain the mode of action in cleaning.
Explain the effects of hard/ soft water on soap.

Group experiments,
Answer questions based on the experiments already carried out.
Expository and descriptive approaches.
Answer oral questions.
Group experiments: form soap lather in different solutions.

Deduce the effects of hard/ soft water on soap.

student book
Distilled water, tap water, rainwater, sodium chloride solution.
Calcium nitrate, Zinc Sulphate, etc.

K.L.B. BK IV
Pages 227-230
K.L.B. BK IV
Pages 232-235

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Soapless detergents.
Polymers and polymerization.

By the end of the lesson, the learner should be able to:
Prepare soapless detergents in the lab.
State merits of soapless detergents over soaps.
Explain the concepts additional and condensation polymerization as methods of making synthetic polymers.
Identify some products of polymerization.
State merits and demerits of synthetic polymers over natural materials.

Teacher demonsration.
Brief discussion.
Teacher exposes and explains new concepts.
Detailed discussion.
Assignment.

student book

K.L.B. BK IV
Pages 235-238

RADIOACTIVITY

Definition of radioactivity.
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.

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:

student book

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

RADIOACTIVITY

Equations involving alpha particles.
Beta particles. Gamma rays.
Radioactive Half-Life.
Radioactive decay curve.
Nuclear fusion and nuclear fission. Applications of radioactivity.

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

Q/A: Review atomic and mass numbers.
Examples of balanced equations.
Supervised practice.
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
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.

student book
Dice.
Graph papers.
student book

K.L.B. BK IV
Page 257
K.L.B. BK IV
Pages 254-5