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| WK | LSN | TOPIC | SUB-TOPIC | OBJECTIVES | T/L ACTIVITIES | T/L AIDS | REFERENCE | REMARKS |
|---|---|---|---|---|---|---|---|---|
| 1 | 2-3 |
SULPHUR AND ITS COMPOUNDS
|
Extraction of Sulphur
Allotropes of Sulphur Physical Properties of Sulphur - Solubility |
By the end of the
lesson, the learner
should be able to:
Define sulphur and state its position in the periodic table. Describe the occurrence of sulphur in nature. Explain the Frasch process for extraction of sulphur. Evaluate the effectiveness of the Frasch process. Investigate the solubility of sulphur in different solvents. Explain the molecular structure of sulphur. Compare solubility in polar and non-polar solvents. State the physical properties of sulphur. |
Q/A: Review group VI elements and electron configuration of sulphur. Teacher demonstration: Using diagrams to explain the Frasch process setup. Discussion: Why ordinary mining is impossible for sulphur deposits. Group work: Students draw and label the Frasch process diagram.
Practical work: Experiment 2(a) - Testing solubility of sulphur in water, benzene, methylbenzene, and carbon(IV) sulphide. Observation and recording in Table Discussion: Explain why sulphur dissolves in organic solvents but not water. Drawing: Puckered ring structure of S8 molecule. |
Charts showing periodic table, Diagram of Frasch process, Samples of sulphur compounds (pyrites, gypsum)
Powdered sulphur, Carbon(IV) sulphide, Evaporating dish, Glass rod, Hand lens, Boiling tubes, Filter paper, Beakers Powdered sulphur, Water, Benzene, Methylbenzene, Carbon(IV) sulphide, Test tubes, Charts showing molecular structure |
KLB Secondary Chemistry Form 4, Pages 160-161
KLB Secondary Chemistry Form 4, Pages 163-164 |
|
| 1 | 4 |
SULPHUR AND ITS COMPOUNDS
|
Physical Properties of Sulphur - Effect of Heat
Chemical Properties of Sulphur - Reactions with Elements |
By the end of the
lesson, the learner
should be able to:
Investigate the effect of heat on sulphur. Describe changes in color and viscosity of molten sulphur. Explain the molecular changes occurring during heating. Identify "flowers of sulphur". |
Practical work: Experiment 2(b) - Heating sulphur and observing changes. Observation: Color changes from yellow to amber to reddish-brown to black. Testing viscosity by inverting test tube. Demonstration: Sublimation of sulphur vapour. Discussion: Breaking of S8 rings to form long chains.
|
Powdered sulphur, Test tubes, Bunsen burner, Cold surface for condensation, Thermometer, Safety equipment
Sulphur, Iron powder, Copper powder, Oxygen gas jar, Deflagrating spoon, Moist litmus papers, Test tubes, Bunsen burner |
KLB Secondary Chemistry Form 4, Pages 164-165
|
|
| 1 | 5 |
SULPHUR AND ITS COMPOUNDS
|
Chemical Properties of Sulphur - Reactions with Acids
|
By the end of the
lesson, the learner
should be able to:
Investigate the reaction of sulphur with concentrated acids. Identify the products formed in these reactions. Write balanced equations for oxidation reactions. Test for sulphate ions using barium chloride. |
Practical work: Experiment 3(b) - Reactions with concentrated nitric(V) acid, sulphuric(VI) acid, and hydrochloric acid. Testing with barium chloride solution. Observation: Formation of sulphate ions, brown fumes, no reaction with HCl. Discussion: Sulphur as a reducing agent, acids as oxidizing agents.
|
Sulphur powder, Concentrated HNO3, Concentrated H2SO4, Concentrated HCl, Barium chloride solution, Test tubes, Fume cupboard access
|
KLB Secondary Chemistry Form 4, Pages 167-168
|
|
| 2 | 1 |
SULPHUR AND ITS COMPOUNDS
|
Uses of Sulphur and Introduction to Oxides
Preparation of Sulphur(IV) Oxide |
By the end of the
lesson, the learner
should be able to:
List the uses of sulphur in industry and agriculture. Identify the two main oxides of sulphur. Compare sulphur(IV) oxide and sulphur(VI) oxide. Plan laboratory preparation methods for sulphur oxides. |
Discussion: Industrial uses - sulphuric acid manufacture, fungicide, vulcanization of rubber, bleaching agents, dyes and fireworks. Q/A: Review oxidation states of sulphur in compounds. Introduction: SO2 and SO3 as important compounds. Preparation planning: Methods for laboratory preparation of SO
|
Charts showing uses of sulphur, Samples of vulcanized rubber, Fungicides, Industrial photographs, Textbook diagrams
Sodium sulphite, Dilute HCl, Round-bottomed flask, Delivery tubes, Gas jars, Concentrated H2SO4 for drying, Acidified potassium chromate(VI) paper |
KLB Secondary Chemistry Form 4, Pages 168-170
|
|
| 2 | 2-3 |
SULPHUR AND ITS COMPOUNDS
|
Physical and Chemical Properties of Sulphur(IV) Oxide
Bleaching Action of Sulphur(IV) Oxide |
By the end of the
lesson, the learner
should be able to:
Investigate the physical properties of SO2 gas. Test the solubility and acidity of SO Write equations for formation of sulphurous acid. Identify the acidic nature of SO Investigate the bleaching properties of SO Compare SO2 bleaching with chlorine bleaching. Explain the mechanism of SO2 bleaching. Relate bleaching to paper manufacturing. |
Practical work: Experiment 5 - Testing color, smell, solubility in water. Testing with dry and moist litmus papers. Universal indicator tests with water and NaOH. Formation of normal and acid salts. Recording observations in Table Safety: Proper ventilation due to toxic nature.
Practical work: Experiment 6 - Placing colored flower petals in SO2 gas. Observation: Temporary bleaching effect. Discussion: SO2 + H2O → H2SO3, reduction of organic dyes. Comparison: Permanent vs temporary bleaching. Application: Paper industry bleaching processes. |
SO2 gas from previous preparation, Litmus papers, Universal indicator, 0.1M NaOH solution, Water, Test tubes, Safety equipment
Colored flower petals (red/blue), SO2 gas jars, Hand lens for observation, Charts comparing bleaching agents |
KLB Secondary Chemistry Form 4, Pages 171-173
KLB Secondary Chemistry Form 4, Pages 173 |
|
| 2 | 4 |
SULPHUR AND ITS COMPOUNDS
|
Reducing Action of Sulphur(IV) Oxide
|
By the end of the
lesson, the learner
should be able to:
Investigate SO2 as a reducing agent. Test reactions with various oxidizing agents. Write ionic equations for redox reactions. Identify color changes in redox reactions. |
Practical work: Experiment 7 - Testing SO2 with acidified potassium dichromate(VI), potassium manganate(VII), bromine water, iron(III) chloride. Recording observations in Table 6. Color changes: Orange to green, purple to colorless, brown to colorless, yellow to pale green. Writing half-equations and overall equations.
|
SO2 gas, Acidified K2Cr2O7, Acidified KMnO4, Bromine water, Iron(III) chloride solution, Concentrated HNO3, Test tubes
|
KLB Secondary Chemistry Form 4, Pages 173-176
|
|
| 2 | 5 |
SULPHUR AND ITS COMPOUNDS
|
Reducing Action of Sulphur(IV) Oxide
|
By the end of the
lesson, the learner
should be able to:
Investigate SO2 as a reducing agent. Test reactions with various oxidizing agents. Write ionic equations for redox reactions. Identify color changes in redox reactions. |
Practical work: Experiment 7 - Testing SO2 with acidified potassium dichromate(VI), potassium manganate(VII), bromine water, iron(III) chloride. Recording observations in Table 6. Color changes: Orange to green, purple to colorless, brown to colorless, yellow to pale green. Writing half-equations and overall equations.
|
SO2 gas, Acidified K2Cr2O7, Acidified KMnO4, Bromine water, Iron(III) chloride solution, Concentrated HNO3, Test tubes
|
KLB Secondary Chemistry Form 4, Pages 173-176
|
|
| 3 | 1 |
SULPHUR AND ITS COMPOUNDS
|
Oxidising Action of Sulphur(IV) Oxide
|
By the end of the
lesson, the learner
should be able to:
Investigate SO2 as an oxidizing agent. Demonstrate reaction with stronger reducing agents. Explain the dual nature of SO Write equations for oxidation reactions by SO |
Practical work: Experiment 8 - Lowering burning magnesium into SO2 gas. Observation: Continued burning, white fumes of MgO, yellow specks of sulphur. Reaction with hydrogen sulphide gas (demonstration). Discussion: SO2 decomposition providing oxygen. Writing equations: 2Mg + SO2 → 2MgO + S.
|
SO2 gas jars, Magnesium ribbon, Deflagrating spoon, Hydrogen sulphide gas, Water droppers, Safety equipment
|
KLB Secondary Chemistry Form 4, Pages 176-177
|
|
| 3 | 2-3 |
SULPHUR AND ITS COMPOUNDS
|
Test for Sulphate and Sulphite Ions & Uses of SO2
Large-scale Manufacture of Sulphuric(VI) Acid - Contact Process |
By the end of the
lesson, the learner
should be able to:
Carry out confirmatory tests for sulphate and sulphite ions. Distinguish between sulphate and sulphite using chemical tests. List the uses of sulphur(IV) oxide. Explain the applications in industry. Describe the contact process for manufacturing H2SO Identify raw materials and conditions used. Explain the role of catalyst in the process. Draw flow diagrams of the contact process. |
Practical work: Experiment 9 - Testing sodium sulphate and sodium sulphite with barium chloride. Adding dilute HCl to precipitates. Recording observations in Table 8. Discussion: BaSO4 insoluble in acid, BaSO3 dissolves. Uses: Raw material for H2SO4, bleaching wood pulp, fumigant, preservative.
Study of flow diagram: Figure 12 - Contact process. Discussion: Raw materials (sulphur, air), burning sulphur to SO Purification: Electrostatic precipitation, drying with H2SO Catalytic chamber: V2O5 catalyst at 450°C, 2-3 atmospheres. Formation of oleum: H2S2O7. Safety and environmental considerations. |
Sodium sulphate solution, Sodium sulphite solution, Barium chloride solution, Dilute HCl, Test tubes, Charts showing industrial uses
Flow chart diagrams, Charts showing industrial plant, Samples of catalyst (V2O5), Photographs of Thika chemical plant, Calculator for percentage calculations |
KLB Secondary Chemistry Form 4, Pages 178-179
KLB Secondary Chemistry Form 4, Pages 179-181 |
|
| 3 | 4 |
SULPHUR AND ITS COMPOUNDS
|
Large-scale Manufacture of Sulphuric(VI) Acid - Contact Process
|
By the end of the
lesson, the learner
should be able to:
Describe the contact process for manufacturing H2SO Identify raw materials and conditions used. Explain the role of catalyst in the process. Draw flow diagrams of the contact process. |
Study of flow diagram: Figure 12 - Contact process. Discussion: Raw materials (sulphur, air), burning sulphur to SO Purification: Electrostatic precipitation, drying with H2SO Catalytic chamber: V2O5 catalyst at 450°C, 2-3 atmospheres. Formation of oleum: H2S2O7. Safety and environmental considerations.
|
Flow chart diagrams, Charts showing industrial plant, Samples of catalyst (V2O5), Photographs of Thika chemical plant, Calculator for percentage calculations
|
KLB Secondary Chemistry Form 4, Pages 179-181
|
|
| 3 | 5 |
SULPHUR AND ITS COMPOUNDS
|
Properties of Concentrated Sulphuric(VI) Acid - Dehydrating Properties
|
By the end of the
lesson, the learner
should be able to:
Investigate the dehydrating properties of concentrated H2SO Demonstrate removal of water from hydrated salts. Show dehydration of organic compounds. Explain the hygroscopic nature of the acid. |
Practical work: Experiment 10 - Adding concentrated H2SO4 to copper(II) sulphate crystals, sucrose crystals, ethanol. Observations: Blue to white crystals, charring of sugar, formation of ethene. Safety: Proper dilution technique - acid to water. Testing evolved gases. Discussion: Chemical vs physical dehydration.
|
Concentrated H2SO4, Copper(II) sulphate crystals, Sucrose, Ethanol, KMnO4 solution, Test tubes, Beakers, Safety equipment, Fume cupboard
|
KLB Secondary Chemistry Form 4, Pages 181-183
|
|
| 4 | 1 |
SULPHUR AND ITS COMPOUNDS
|
Properties of Concentrated Sulphuric(VI) Acid - Oxidizing Properties
|
By the end of the
lesson, the learner
should be able to:
Investigate the oxidizing properties of concentrated H2SO Test reactions with metals and non-metals. Identify the products of oxidation reactions. Write balanced equations for redox reactions. |
Practical work: Experiment 10 (continued) - Reactions with copper foil, zinc granules, charcoal. Testing evolved gases with acidified K2Cr2O7 paper, lime water. Observations: SO2 evolution, color changes. Discussion: H2SO4 → SO2 + H2O + [O]. Writing half-equations and overall equations.
|
Copper foil, Zinc granules, Charcoal powder, Concentrated H2SO4, Acidified K2Cr2O7 paper, Lime water, Test tubes, Bunsen burner
|
KLB Secondary Chemistry Form 4, Pages 183-184
|
|
| 4 | 2-3 |
SULPHUR AND ITS COMPOUNDS
|
Properties of Concentrated Sulphuric(VI) Acid - Oxidizing Properties
Properties of Concentrated Sulphuric(VI) Acid - Displacement Reactions |
By the end of the
lesson, the learner
should be able to:
Investigate the oxidizing properties of concentrated H2SO Test reactions with metals and non-metals. Identify the products of oxidation reactions. Write balanced equations for redox reactions. Investigate acid displacement reactions. Demonstrate formation of volatile acids. Test the evolved gases for identification. Write equations for displacement reactions. |
Practical work: Experiment 10 (continued) - Reactions with copper foil, zinc granules, charcoal. Testing evolved gases with acidified K2Cr2O7 paper, lime water. Observations: SO2 evolution, color changes. Discussion: H2SO4 → SO2 + H2O + [O]. Writing half-equations and overall equations.
Practical work: Experiment 10 (continued) - Reactions with potassium nitrate and sodium chloride. Testing evolved gases with moist blue litmus, concentrated ammonia. Observations: Brown fumes (NO2), white fumes (HCl). Discussion: Less volatile acid displacing more volatile acids. Industrial applications. |
Copper foil, Zinc granules, Charcoal powder, Concentrated H2SO4, Acidified K2Cr2O7 paper, Lime water, Test tubes, Bunsen burner
Potassium nitrate crystals, Sodium chloride crystals, Concentrated H2SO4, Moist blue litmus paper, Concentrated ammonia, Test tubes, Bunsen burner |
KLB Secondary Chemistry Form 4, Pages 183-184
KLB Secondary Chemistry Form 4, Pages 184 |
|
| 4 | 4 |
SULPHUR AND ITS COMPOUNDS
|
Reactions of Dilute Sulphuric(VI) Acid - With Metals
|
By the end of the
lesson, the learner
should be able to:
Investigate reactions of dilute H2SO4 with metals. Compare reactivity of different metals. Test for hydrogen gas evolution. Relate reactions to reactivity series. |
Practical work: Experiment 11 - Reactions with magnesium, zinc, copper. Testing evolved gas with burning splint. Recording observations in Table 10. Discussion: More reactive metals above hydrogen displace it. Vigour of reaction decreases down reactivity series. Writing ionic equations.
|
Magnesium ribbon, Zinc granules, Copper turnings, Dilute H2SO4, Test tubes, Burning splints, Reactivity series chart
|
KLB Secondary Chemistry Form 4, Pages 184-185
|
|
| 4 | 5 |
SULPHUR AND ITS COMPOUNDS
|
Reactions of Dilute Sulphuric(VI) Acid - With Carbonates
|
By the end of the
lesson, the learner
should be able to:
Investigate reactions of dilute H2SO4 with carbonates. Test for carbon dioxide evolution. Explain why some reactions stop prematurely. Compare reactions of different metal carbonates. |
Practical work: Experiment 12 - Reactions with sodium carbonate, zinc carbonate, calcium carbonate, copper(II) carbonate. Testing evolved gas with lime water. Recording observations in Table 1 Discussion: Formation of insoluble calcium sulphate coating. Effervescence and CO2 identification.
|
Sodium carbonate, Zinc carbonate, Calcium carbonate, Copper(II) carbonate, Dilute H2SO4, Lime water, Test tubes
|
KLB Secondary Chemistry Form 4, Pages 185-186
|
|
| 5 | 1 |
SULPHUR AND ITS COMPOUNDS
|
Reactions of Dilute Sulphuric(VI) Acid - With Oxides and Hydroxides
|
By the end of the
lesson, the learner
should be able to:
Investigate reactions of dilute H2SO4 with metal oxides and hydroxides. Identify neutralization reactions. Explain formation of insoluble sulphates. Write equations for acid-base reactions. |
Practical work: Experiment 13 - Reactions with magnesium oxide, zinc oxide, copper(II) oxide, lead(II) oxide, sodium hydroxide. Recording observations in Table 1 Discussion: Salt and water formation, immediate stopping with lead(II) oxide due to insoluble PbSO Acid-base neutralization concept.
|
Metal oxides (MgO, ZnO, CuO, PbO), NaOH solution, 2M H2SO4, Test tubes, Bunsen burner for warming
|
KLB Secondary Chemistry Form 4, Pages 186-187
|
|
| 5 | 2-3 |
SULPHUR AND ITS COMPOUNDS
|
Reactions of Dilute Sulphuric(VI) Acid - With Oxides and Hydroxides
Hydrogen Sulphide - Preparation and Physical Properties |
By the end of the
lesson, the learner
should be able to:
Investigate reactions of dilute H2SO4 with metal oxides and hydroxides. Identify neutralization reactions. Explain formation of insoluble sulphates. Write equations for acid-base reactions. Describe laboratory preparation of hydrogen sulphide. Set up apparatus for H2S preparation. State the physical properties of H2S. Explain the toxicity and safety precautions. |
Practical work: Experiment 13 - Reactions with magnesium oxide, zinc oxide, copper(II) oxide, lead(II) oxide, sodium hydroxide. Recording observations in Table 1 Discussion: Salt and water formation, immediate stopping with lead(II) oxide due to insoluble PbSO Acid-base neutralization concept.
Demonstration: Figure 13 apparatus setup for H2S preparation. Reaction: FeS + 2HCl → FeCl2 + H2S. Collection over warm water due to solubility. Drying: Using anhydrous CaCl2 (not H2SO4). Properties: Colorless, rotten egg smell, poisonous, denser than air. Safety precautions in handling. |
Metal oxides (MgO, ZnO, CuO, PbO), NaOH solution, 2M H2SO4, Test tubes, Bunsen burner for warming
Iron(II) sulphide, Dilute HCl, Apparatus for gas generation, Anhydrous CaCl2, Gas jars, Safety equipment, Fume cupboard |
KLB Secondary Chemistry Form 4, Pages 186-187
KLB Secondary Chemistry Form 4, Pages 187-188 |
|
| 5 | 4 |
SULPHUR AND ITS COMPOUNDS
|
Chemical Properties of Hydrogen Sulphide
|
By the end of the
lesson, the learner
should be able to:
Investigate H2S as a reducing agent. Test reactions with oxidizing agents. Demonstrate precipitation of metal sulphides. Write ionic equations for redox reactions. |
Practical demonstrations: H2S with bromine water, iron(III) chloride, acidified KMnO4, K2Cr2O7. Precipitation tests: H2S with copper(II) sulphate, lead(II) nitrate, zinc sulphate. Color changes: Brown to colorless, yellow to green, purple to colorless. Formation of black, yellow, and white precipitates.
|
H2S gas, Bromine water, Iron(III) chloride, KMnO4, K2Cr2O7, Metal salt solutions, Test tubes, Droppers
|
KLB Secondary Chemistry Form 4, Pages 188-190
|
|
| 5 | 5 |
SULPHUR AND ITS COMPOUNDS
|
Chemical Properties of Hydrogen Sulphide
|
By the end of the
lesson, the learner
should be able to:
Investigate H2S as a reducing agent. Test reactions with oxidizing agents. Demonstrate precipitation of metal sulphides. Write ionic equations for redox reactions. |
Practical demonstrations: H2S with bromine water, iron(III) chloride, acidified KMnO4, K2Cr2O7. Precipitation tests: H2S with copper(II) sulphate, lead(II) nitrate, zinc sulphate. Color changes: Brown to colorless, yellow to green, purple to colorless. Formation of black, yellow, and white precipitates.
|
H2S gas, Bromine water, Iron(III) chloride, KMnO4, K2Cr2O7, Metal salt solutions, Test tubes, Droppers
|
KLB Secondary Chemistry Form 4, Pages 188-190
|
|
| 6 | 1 |
SULPHUR AND ITS COMPOUNDS
|
Pollution Effects and Summary
|
By the end of the
lesson, the learner
should be able to:
Explain environmental pollution by sulphur compounds. Describe formation and effects of acid rain. Suggest methods to reduce sulphur pollution. Summarize key concepts of sulphur chemistry. |
Discussion: Sources of SO2 pollution - burning fossil fuels, metal extraction, H2SO4 manufacture. Formation of acid rain: SO2 + H2O → H2SO3 → H2SO Effects: Plant damage, aquatic life destruction, building corrosion, soil acidification. Control measures: Scrubbing with Ca(OH)2, catalytic converters. Revision: Key reactions, properties, uses.
|
Charts showing pollution effects, Photographs of acid rain damage, Environmental data, Summary charts of reactions, Industrial pollution control diagrams
|
KLB Secondary Chemistry Form 4, Pages 190-194
|
|
| 6 | 2-3 |
ACIDS, BASES AND SALTS
|
Definition of Acids
Strength of Acids Definition of Bases |
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 - Define a base in terms of hydroxide ions -Investigate effect of calcium hydroxide in water -Test solutions with litmus paper -Explain dissociation of bases in water |
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.
Teacher demonstration: Place dry calcium hydroxide on dry red litmus paper. Dissolve calcium hydroxide in water, test with litmus paper and phenolphthalein. Discuss observations and write dissociation equation. Define bases in terms of OH⁻ ions. |
Magnesium strips, zinc carbonate, 2M HCl, 2M ethanoic acid, 2M H₂SO₄, 2M ethanedioic acid, test tubes, test tube rack
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 |
KLB Secondary Chemistry Form 4, Pages 1-3
KLB Secondary Chemistry Form 4, Pages 5-6 |
|
| 6 | 4 |
ACIDS, BASES AND SALTS
|
Strength of Bases
Acid-Base Reactions |
By the end of the
lesson, the learner
should be able to:
- Compare strengths of bases using pH values -Determine strengths of bases by comparing their electrical conductivity -Classify bases as either strong or weak -Explain complete and partial ionization of bases |
Class experiment: Test pH of 2M NaOH and 2M ammonia solution using universal indicator. Test electrical conductivity of both solutions using same apparatus as acids. Compare deflections and pH values. Explain in terms of OH⁻ ion concentration and complete vs partial ionization.
|
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 5-7
|
|
| 6 | 5 |
ACIDS, BASES AND SALTS
|
Effect of Solvent on Acids
|
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 |
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.
|
HCl gas, distilled water, methylbenzene, magnesium ribbon, calcium carbonate, litmus paper, test tubes, gas absorption apparatus
|
KLB Secondary Chemistry Form 4, Pages 7-9
|
|
| 7 | 1 |
ACIDS, BASES AND SALTS
|
Effect of Solvent on Bases
Amphoteric Oxides and Hydroxides |
By the end of the
lesson, the learner
should be able to:
- Investigate effect of polar and non-polar solvents on ammonia gas -Compare ammonia behavior in water vs methylbenzene -Explain formation of ammonium hydroxide -Write equations for ammonia dissolution in water |
Class experiment: Test dry ammonia with dry litmus. Dissolve ammonia in water and test with litmus. Dissolve ammonia in methylbenzene and test with litmus. Record observations in table. Write equation for NH₃ + H₂O reaction. Explain why only aqueous ammonia shows basic properties.
|
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 |
KLB Secondary Chemistry Form 4, Pages 9-10
|
|
| 7 | 2 |
ACIDS, BASES AND SALTS
|
Definition of Salts and Precipitation
|
By the end of the
lesson, the learner
should be able to:
- Define a salt as an ionic compound -Define a precipitate -Investigate precipitation reactions -Write ionic equations showing formation of precipitates |
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.
|
Na₂CO₃ solution, salt solutions containing various metal ions, test tubes, droppers
|
KLB Secondary Chemistry Form 4, Pages 11-14
|
|
| 7-9 |
END TERM THREE EXAMINATION |
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| 9 |
END TERM THREE AND CLOSURE |
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