Planning paper 3

CONTOH SOALAN DAN JAWAPAN ESEI KERTAS 3

PERIODIC TABLE OF ELEMENTS

1.

Using the suitable apparatus and materials, you are required to design a laboratory experiment to investigate / determine the reactivity of above mentioned elements when they react with water.

Statement of problem: How does the reactivity of lithium, sodium and potassium/group 1 elements change when they react with water?

Variables:Manipulated : Different types of alkali metals // Lithium, sodium, potassiumResponding : Reactivity of alkali metals with waterConstant variable: Size of alkali metals, water

Hypothesis:

When going down Group 1, the reactivity of the metals with water increases.Lists of substances and apparatusLithium, sodium, potassium, water, small knife, forcep, basin, filter paper

Procedure:

1. Fill a basin / trough with water

2. Cut a small piece of lithium using a knife and forceps

3. Dry the oil on the surface of the lithium with filter paper

4. Place the lithium slowly onto water surface in a basin / trough

5. Record your observations

6. Repeat steps 1 – 5 using sodium and potassium to replace lithium one by one

Tabulation of data:

Alkali Metals Observations Lithium Sodium Potassium

1

Three elements of group 1 in the Periodic Table Lithium Sodium Potassium


2. Chlorine and bromine show similar chemical properties but differ the reactivity.By using a suitable reaction, plan an experiment to compare the reactivity of these elements.

Problem statement:How does the reactivity of chlorine and bromine differ when they react with hot iron wool?

Variable:Manipulated: Type of halogens // chlorine and bromineResponding: reactivity of reaction (towards hot iron wool)Fixed: iron wool

Hypothesis:Chlorine is more reactive than bromine towards hot iron.

Apparatus and substances:Combustion tube, delivery tubes, Bunsen burner, retort stand and clamp, stoppersChlorine gas, liquid bromine, iron wool, soda lime

Procedure:

1. Clamp combustion tube horizontally to the retort stand.2. Place iron wool in the middle of the combustion tube.3. Heat the iron wool in the combustion tube strongly.4. Pass through chlorine gas over the hot iron wool until no further change occur.5. The excess chlorine gas is absorbed by soda lime.6. Record the observation.7. Repeat the experiment by using bromine.

Tabulation of data

Halogens Observation Chlorine gasLiquid bromine

2


3. Oxides can be classified into basic oxide, acidic oxide and amphoteric oxide. An oxide that dissolves in acid only is a basic oxide. An oxide that dissolves in alkali only is an acid oxide. An oxide that dissolves in both acid and alkali is an amphoteric oxide.

Plan a laboratory experiment to study the properties // acid-base properties of oxides of elements in Period 3.

Problem statement:How does the acid-base properties // pH values of oxides of elements change across Period 3?

Hypothesis :An acidic property of the oxides of elements increases where as basic properties of the oxides of elements decrease across period 3.

Variables :Manipulated : oxides of element of Period 3Responding variables: pH values in water // solubility in acid or alkaliFixed : water // universal indicator // pH meter // nictric acid // sodium hydroxide solution

Apparatus :Test tube, test tube rack, gas jar, gas jar cover, 100 cm3 measuring cylinder.

Material: Sodium oxide, magnesium oxide, aluminium oxide, silicon (IV) oxide, phosphorus pentoxide, sulphur dioxide gas, 1.0 mol dm-3 nictric acid and 1.0 mol dm-3 sodium hydroxide solution.

Procedure:1. A small piece of sodium oxide is put into a test tube half filled with distilled water.2. The mixture is shaken.3. Three drop of universal indicator are added to the mixture using dropper // pH meter is dipped into the mixture.4. The colour of the mixture is observed and the pH value is recorded.5. The procedure is repeated for the other oxides.

Tabulation of data:

Oxides Solubility in water and pH values

3


(a)

Procedure:

1. A little / 0.5 g // half spatula R2O3 powder is put into two separate test tubes.2. 5 cm3 of 1.0 mol dm-3 sodium hydroxide solution is added into the first test tube.3. 5 cm3 of 1.0 mol dm-3 nitric acid is added into the second test tube.4. Both test tubes are heated slowly.5. Repeat step 1-4 for MO and TO2.6. Record the observations.

(b) Variables:manipulated: oxide R2O3, MO and TO2

Responding : acid-base properties Fixed : sodium hydroxide solution, nitric acid

(c) R2O3 – amphoteric oxideMO – basic oxideTO2 – Acidic oxide

(d) M, R, T

(e) MO insoluble in water4


TOPIC: CHEMICAL BONDS

Diagram

4. Diagram shows the apparatus set-up for an experiment to compare the electrical conductivity between two types of chemical compound, P and Q.

(a) Problem statement:How does the type of compounds affect the electrical conductivity?

(b) Variable: Manipulated : Type of chemical compoundResponding : Electrical conductivity / the light of the bulb Controlled : carbon electrode / Mass of the substance

(c) Hypothesis :Ionic compound can conduct electricity while covalent compound does not conduct

electricity in molten state.

(d) Materialssolid lead(II)bromide , naphthalene, C10H8

ApparatusCrucible, Batteries, Bulb, Carbon electrodes, Tripod stand, Bunsen burner, Pipe-clay triangle, Connecting wire and crocodile clip.

(e) Procedure :1 Fill a crucible with a solid lead(II)bromide, PbBr2 until it is half full.2 Connect the carbon electrodes to the batteries and bulb. 3 Heat the solid lead(II)bromide until it melts.4 Dip /place/ immerse carbon electrodes into the molten lead(II)bromide, PbBr2 5 Record the observation.6 Repeat steps 1 to 5 / experiment using naphthalene, C10H8

(f) Tabulation of data:

Chemical compound ObservationLead(II)bromide Naphthalene

5

P


TOPIC: ELECTROCHEMISTRY

5. Plan a laboratory experiment to construct the electrochemical series based on the potential difference between two metals. You are given copper (II) sulphate solution, Mg, Zn, Fe, Pb and Cu strips.(a) Aim:

To construct the Electrochemical series based on the potential difference between two metals.

Statement of problem: How does the Electrochemical series be constructed based on the potential difference between two metals?

(b) VariableManipulated : pair of metal

Responding : potential difference / voltmeter reading/ voltage valueFixed : electrolyte (copper (II) sulphate solution/ / positive (copper)

(c) Hypothesis : The further the distance between two metals in the Electrochemical series, the higher the potential differences/ voltage/ voltmeter reading.

(d) Substances : copper (II) sulphate solution 0.5 mol dm-3 , Mg, Zn, Fe, Pb and Cu strips, sand paper

Apparatus: beaker, connecting wire with crocodile clip, voltmeter

(e) Procedure : 1. Clean the metals with sandpaper 2. Pour 50.0 cm3 copper (II) sulphate solution into a beaker. 3. Dip / immerse the Mg and Cu strip into the beaker. 4. Complete the circuit // connect the electrodes to a voltmeter using connecting wire with crocodile clip. 5. Record the potential difference / voltmeter reading. 6. Repeat steps 1 to 5 using Zn, Fe and Pb to replace Mg.


Pair of metal Potential difference, VZn and CuMg and CuFe and CuPb and Cu

6


Diagram 2.1 Battery [voltaic cell / electrochemical cell]

6. Diagram shows several electrochemical cells with different voltages. Identify the factors that influence the differences in the voltage. Plan a laboratory experiment to construct an electrochemical cell to determine one factor that influences the differences in the voltage.

(a) Statement of problem:How does //Does the position /distance between two metals in electrochemical series affect the voltmeter reading / voltage/ potential difference?

(b) VariableManipulated : pair of metal

Responding : potential difference / voltmeter reading/ voltage valueFixed : electrolyte (name) / positive terminal (name) /

volume and concentration of electrolyte(c) Hypothesis :

The further the distance between two metals electrode in the Electrochemical Series, the higher the potential differences/ voltage/ voltmeter reading.

d) Substances : copper (II) sulphate solution 0.5 mol dm-3 , Mg,Zn, Fe, Pb and Cu strips, sand paper Apparatus : beaker, connecting wire with crocodile clip, voltmeter

(e) Procedure : 1. Clean the metals with sandpaper 2. Pour 50.0 cm3 copper (II) sulphate solution into a beaker. 3. Dip / immerse the Mg and Cu strip into the beaker. 4. Complete the circuit // connect the electrodes to a voltmeter using connecting wire with crocodile clip. 5. Record the potential difference / voltmeter reading. 6. Repeat steps 1 to 5 using Zn, Fe and Pb to replace Mg.


Pair of metal/electrode Potential difference, VZn and CuMg and CuFe and CuPb and Cu

7


7. Diagram 6.1 and 6.2 show Experiment I and Experiment II to investigate the effect of type of electrodes on the products formed at the electrodes.

Experiment I

Experiment II

Based on Diagram 6.1 and Diagram 6.2 above, plan a laboratory experiment to investigate the effect of the type of electrode to the product at anode.

(a) Aim : To determine the effect of type of electrode on the selection of ions to be discharged at the anode/ on the product formed at the anode.

(b) Variable:Manipulated variable:

Type of electrodes//Carbon electrodes and copper electrodesResponding variable:

Product formed at anodeFixed variable:

Electrolyte// copper(II)sulpahte solution

(c) Hypothesis:When carbon electrodes are used, bubbles/oxygen gas released at anode, when copper electrodes are used, anode becomes thinner/ionised

8

Diagram 6.1

After 30 minutes

Carbon electrodes Carbon electrodes

After 30 minutes

Copper electrodes

0.01 mol dm-3 copper(II) sulphate solution

Diagram 6.2




(d) Materials:Copper(II) sulphate solution (0.5 – 2.0) mol dm-3, copper rods,

Apparatus:Carbon rods, electrolytic cell, battery, ammeter, connecting wires, test tube

(e) Procedure:1. Half filled the electrolytic cell/beaker with copper(II) sulphate solution2. A test tube filled with copper(II) sulphate solution is inverted over the anode carbon

electrode3. Both electrodes are connected to the batteries using connecting wires//Complete the circuit4. Record the observations at the anode


Type of electrodes Observation at anodeCarbonCopper

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8. The concentration of the electrolyte will affect the products formed at the electrodes during electrolysis.By using different concentration of sodium chloride solution, design an experiment to investigate the above statement.

Problem statement:How does the concentration of the electrolyte (sodium chloride solution) will affect the products formed at the anode electrode during electrolysis?

Variable:Manipulated: concentration of the electrolyte (sodium chloride solution)Responding: products formed at the anodeFixed: carbon electrodes, sodium chloride solution, blue litmus paper

Hypothesis: When concentrated sodium chloride solution is used, greenish yellow gas released at the anode, when diluted sodium chloride solution is used, colourless gas released at the anode.

Apparatus and Substances:Carbon rods, electrolytic cell, battery, ammeter, connecting wires, test tubes1.0 mol dm-3 sodium chloride solution, 0.0001 mol dm-3 sodium chloride solution, litmus paper

Procedure:

1. Half filled the electrolytic cell/beaker with 1.0 mol dm-3 sodium chloride solution.2. A test tube filled with 1.0 mol dm-3 sodium chloride solution is inverted over the anode

carbon electrode.3. Both electrodes are connected to the batteries using connecting wires//Complete the circuit4. Record the observations at the anode.5. Repeat step 1-4 by using 0.0001 mol dm-3 sodium chloride solution.


Concentration electrolyte / sodium chloride solution

Observation at anode // Product at anode

1.0 mol dm-3

0.0001 mol dm-3

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9. The displacement reaction is a chemical change which takes place when a metal placed higher in the electrochemical series displaces a metal below it from its salt solution.

Iron displaces copper from its salt solution because it is placed higher than copper in the electrochemical series. Based on this principle, plan a laboratory to construct the electrochemical series.

Problem statement:How to construct the electrochemical series of metals based on the displacement of metals?

Hypothesis:The greater the number of metals that can be displaced by a metal from their solutions, the higher is its position in the electrochemical series.

Variables :Manipulated : pair of metal and salts solution usedResponding : the number of displacement reactions occurred fixed : concentration and volume of solution.

Apparatus: test tube, test tube rackMaterials: 1 mol dm-3 of magnesium nitrate, zinc nitrate, lead(II)nitrate, copper(II)nitrate solution. Magnesium, zinc, lead, and copper strip.

Procedure:1. Pour 5 cm3 1 mol dm-3 of magnesium nitrate, zinc nitrate, lead(II)nitrate, copper(II)nitrate solution solutions into four separate test tubes.2. Place a strip of magnesium ribbon into each test tube.3. Record the observation. 4. Repeat step 1-3 using zinc, lead and copper to replace the magnesium strip. For each repetition, use a fresh salt solution. 5. Record all observations.

Tabulation Data:

solution salt Metal

Magnesium nitrate

Zinc nitrate Lead(II) nitrate Copper(II) nitrate

MgZnPbCu

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TOPIC: ACIDS AND BASES

10.

Plan a laboratory experiment to investigate the role of water in showing the properties of acids.

(a) Statement of problem:Does an acid need water to show its acidic properties?

(b) VariableManipulated : type of solvents (water and tetrachloromethane/ propanone)

Responding : properties of acid / change in colour of blue litmus paperFixed : type of acid (ethanoic acid), litmus paper

(c) Hypothesis :Water is needed for an acid to show its acidic properties // An acid will show its acidic

properties when dissolved in water.

* Operational definition: Blue litmus paper turning red when water is added to glacial ethanoic acid indicates acidic properties.

(d) Materials:Glacial ethanoic acid, distilled water and tetrachloromethane/ propanone, blue itmus paper

Apparatus:Test tube, droppers, test tube rack

(e) Procedure:1. Label three test tubes as A, B and C. Place the test tube in a test tube rack.2. Put 2 cm3 glacial ethanoic acid into each test tube using dropper.3. Add 2 cm3 distilled water in test tube B4. Add 2 cm3 tetrachloromethane/ propanone in test tube C.5. Place dry blue litmus paper into the test tubes.6. Record the observation.

(f) Tabulation of data

Test tube / solvents Observation

AB / distilled waterC/ tetrachloromethane/ propanone

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Glacial ethanoic acid, CH3COOH is dry. It only shows acidic properties when water is added to it.


11. An experiment is carried out to measure the pH values of hydrochloric acid having different molarities.Plan a laboratory experiment to investigate the relationship between pH values and molarity of the acids.

Sample answer:

Statement of the problem:How does the molarity of the acids affect the pH values?

Variable: Manipulated : molarity of acidResponding : pH valueFixed : hydrochloric acid, pH meter

Hypothesis : When the molarity of the acid increases, the pH value decreases.

Materials : 0.1 mol dm-3 , 0.01 mol dm-3, 0.001 mol dm-3 hydrochloric acid Apparatus : beaker, pH meter, measuring cylinder.

Procedure: 1. pour 50 cm3 of 0.1 mol dm-3 hydrochloric acid into a beaker, 2. Dip pH meter into the acid.3. Record the pH meter reading. 4. Repeat step 1 to 3 by using 0.01 mol dm-3, 0.001 mol dm-3 hydrochloric acid. Tabulation data:

Molarity of acid, mol dm-3 pH value0.10.010.001

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TOPIC : SALTS

Diagram shows seven test tube containing lead(II)chromate(VI) precipitate which is formed when lead(II)nitrate solution reacts with potassium chromate(VI) solution. Based on diagram, paln one laboratory experiment to construct the ionic equation for the formation of lead (II) chromate(VI).

12. Aim : To construct the ionic equation for the formation of lead (II) chromate(VI)Problem Statement: How does an ionic equation for the formation of lead chromate (VI) can be constructed? // How to construct an equation for the formation of lead chromate (VI)?

Hypothesis :As the volume potassium chromate (VI) used is increases, the height of the yellow precipitate increases until it achieves a maximum height // constant// no change

Variables:Manipulated : Volumes of 0.5 mol dm-3 potassium chromate (VI) solution.

Responding : Height of yellow precipitate.

Fixed : Size of test tubes, volume and concentration of lead (II) nitrate solution, concentration of potassium chromate (VI) solution.

Apparatus : Test tubes of the same size, test tube rack, burette, retort stand with clamp, ruler, glass rod, dropper.

Material : 0.5 mol dm-3 potassium chromate (VI) solution, 0.5 mol dm-3 lead (II) nitrate solution.

Procedure :

1. Seven test tubes of the same size were labelled from number 1 to 7. They were placed in a test tube rack.

2. A burette was filled 0.5 mol dm-3 lead (II) nitrate solution, 5.00 cm3 of the lead (II) nitrate solution was run into each the seven tubes.

3. Another burette was filled with 0.5 mol dm-3 potassium chromate (VI) solution.4. 1 cm3 of potassium chromate (VI) solution from the burette was added into the first test

tubes 5. Repeat the experiment with different volume of potassium chromate(VI) solution. The

mixture in each test tube was stirred with a clean glass rod.6. The test tubes were left aside for about an hour.7. The height of the precipitate in each test tube was measured and recorded.

Results:

Test tube 1 2 3 4 5 6 7Volume of 0.5 mol dm-3

K2Cr O4 /cm31.00 2.00 3.00 4.00 5.00 6.00 7.00

Height of precipitate (cm)

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Garden snail

13. The soft body of the garden snail is protected by its cone-shaped shell. What kind of chemical compound found in the shell to give it its hardness and waterproof nature? Actually the above mentioned shell consists of calcium carbonate, CaCO3. It is an insoluble salt. Referring to the situation above, plan a laboratory experiment to compare the solubility of nitrate, sulphate, carbonate and chloride salt in water.

Sample answer:

Problem statement:How does solubility of nitrate, sulphate, carbonate and chloride salt in water? //Does all nitrate, sulphate, carbonate and chloride salt soluble in water?

VariablesManipulated: nitrate, sulphate, carbonate and chloride salt // Type of saltsResponding: solubility of saltFixed: volume and temperature of water // quantity of salt powder

Hypothesis:Some of salts soluble in water but other salts insoluble in water // Some of salts soluble in water, while some are not.

Material:Any suitable nitrate, sulpahte, chloride and carbonate salts soluble and insoluble in waterdistilled water.

Apparatus:Test tube, test tube rack and spatula.

Procedure:1. Half spatula of zinc nitrate powder is put into a test tube.2. Pour 5 cm3 of distilled water into the test tube.3. Stir the mixture / shake the test tube4. Observe and record the solubility of salt.5. Repeat step 1 to 4 by using various salt powder.Tabulation of data:

Salt Solubility in water / observationZinc nitrateCalcium sulphatePotassium carbonateLead(II)chlorideMagnesium chlorideCopper(II) carbonateCopper (II)sulphate

15


TOPIC: MANUFACTURED SUBSTANCES IN INDUSTRY

14 . Copper wire in electric cable can be easily bent by hand. A coin cent made of an alloy of copper with tin and zinc cannot be bent easily.Referring to the situation above, plan a laboratory experiment to investigate the effect of alloy formation on the hardness of a metal.

(a) Statement of problem:Does the formation of alloy increase the hardness of a metal?

(b) VariableManipulated : copper and bronze / copper and brass

Responding : size of the dent made by the metal ball bearing on the blockFixed : mass of the weight // type of metal ball // the height of the thread

(c) Hypothesis : Bronze is harder than copper

Operational definition: If smaller dent produced when I kg weights is dropped on the metal block, then the metal block is harder.

(d) List of apparatus: copper block, bronze/ brass block, steel ball bearing, weight 1 kg, ruler, rope, retort stand.

(e) Procedure1. Put the steel ball bearing on the copper block.2. Pull the rope that tied to the weight until the weight is 60 cm high on the copper block.3. Drop the weight onto the steel ball bearing.4. Measure the diameter of the dent made on the copper block and records it.5. Repeat the activity 3/5 times.6. Repeat step 1 to 5 by using the bronze block, replacing the copper block.


Name of metal Diameter of the dent (cm) Average , cm1 2 3 4 5

Metal/ copperAlloy / bronze

16


15. You have learnt the steel is an alloy of iron. Steel is harder than pure iron. Both iron and steel can rust when exposed to air and water. Do they rust at the same rate?

Aim : To compare the rate of rusting between iron, steel and stainless steel

Problem Statement:How does the rate of rusting between iron, steel and stainless steel differ?

Hypothesis Iron rust faster than steel and steel rust faster than stainless steel.

Operational definition for rusting: The more the blue colour produced, when the metal is placed in test tube containing the mixture of hot jelly and potassium hexacyanoferrate (III) solution, the higher the rate of rusting.

VariablesManipulated: Iron, steel and stainless steel.Responding : intensity / amount of dark blue colour / rate of rusting Fixed : size of nail, concentration of solution, duration of rusting

Apparatus:test tube, test tube rackMaterials: iron nail, steel nail, stainless steel nail, mixture of hot jelly and potassium hexacyanoferrate (III) solution.

Procedure:1. Clean the nails with sand paper (to remove the rust from all the nails).2. Place the iron nail, steel nail and stainless steel nail into the test tube A, B and C respectively.3. Prepare a 5 % jelly solution by adding 5 g jelly to 100 cm3 of boiling water. Add a few drop of potassium hexacyanoferrate (III) solution.4. Pour the hot jelly into the test tubes until all the nails are fully immersed.5. Leave the nails for 3 days.6. Observe and record the intensity of the dark blue colour.

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Test tube The intensity of the dark blue colour ABC


TOPIC: CARBON COMPOUNDS

16. Diagram shows two reagent bottles containing two colourless liquid of carbon compounds P and Q respectively.

P Q

These two liquid are hexene and ethanioc acid.Using suitable reagent, plan a laboratory experiment to identify the colourless liquid.

Problem statement:How to determine and identify hexane and ethanoic acid (liquid P and liquid Q)?

Variables:Manipulated variable: Hexene and ethanoic acid // Liquid P and QResponding variable: Colour change of reagent // gas bubbles release

Constant variable: Volume of hexene and ethanoic acid // acidified potassium manganate(VII) // magnesium ribbon// zinc powder // calcium carbonate

Hypothesis If liquid P decolourised purple colour of acidified potassium manganate(VII), so liquid P is hexene // Acid will produce gas bubbles with Magnesium (Calcium carbonate)

Apparatus Test tube, dropper, and stopperMaterialsLiquid P, Liquid Q, acidified potassium manganate(VII) solution / Magnesium ribbon, zinc power or calcium carbonate chips)

Procedure:1. 2 cm3 liquid P and liquid Q are poured into two different test tubes.2. Three d r o p s o f a c i d i f i e d p o t a s s i u m m a n g a n a t e (VII) are added into the test

tubes // a piece of magnesium ribbon are dipped into the test tubes. 3. The test tubes are closed with stoppers.4. The mixtures are shaken.

5. The observations are recorded.

Tabulation of data:

Liquid Observation PQ

18


17.

Aim : To compare the elasticity of vulcanised and unvulcanised rubber

Problem statement: How does (the elasticity of) vulcanised rubber differ from unvulcanised rubber?

Hypothesis: Vulcanised rubber is more elastic than unvulcanised rubber

Variable Manipulated : vulcanised rubber and unvulcanised rubberResponding : length of rubber strip / elasticityFixed : mass of weight, size of rubber

Material and apparatus: Retort stand, bulldog clip, meter ruler, weight, vulcanised and unvulcanised rubber

Procedure:1. Hang both rubber strips to the retort stand with bulldog clip.2. Measure the initial length of both rubber strips and record.3. Hang 50 g weight to the end of each rubber using bulldog clip.4. Remove the weight and measure the length of both rubber strips and record.//5. Record all the data obtained.

Result / Data

Type of rubber Initial length , cm Length after removal of weight , cm vulcanised unvulcanised

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18.Aim : To compare / investigate the strength of vulcanised and unvulcanised rubber

Problem statement: How does the strength of vulcanised rubber differ from unvulcanised rubber?

Hypothesis: Vulcanised rubber is stronger than unvulcanised rubber.

Variable:Manipulated : vulcanised rubber and unvulcanised rubberResponding : change in length of the rubber stripFixed : mass of weight, size of rubber strips

Material and apparatus:

Retort stand with clamp, bulldog clip, meter ruler, weight (20-50 g), vulcanised and unvulcanised rubber strips.

Procedure:

1. Hang a strip of vulcanised rubber to the retort stand with clip / bulldog clip.2. Measure and record the initial length of the rubber strip with meter ruler.3. Hang (20-50) g weight to the bottom end of the rubber strip using clip / bulldog clip.4. Measure and record the length of the rubber strips.5. Repeat step 1-4 replacing vulcanised rubber with unvulcanised rubber.

Result / Data

Type of rubber Initial length , cm Final length , cm vulcanised unvulcanised

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19. An acid is used to coagulate latex while alkali can prevent the coagulation of latex. Based on this idea, plan a laboratory experiment to investigate the effect of acid and alkali on the coagulation of latex.

(a) Problem statement:How does ethanoic acid and ammonia solution affects the coagulation of latex?

(b) VariableManipulated : ethanoic acid and ammonia solution

Responding : coagulate of latexFixed : latex

(c) Hypothesis :Ethanoic acid coagulates the latex while ammonia solution does not coagulate the latex.

(d) Materials:Latex , ethanoic acid 0.5 mol dm-3 and ammonia solution

Apparatus:Beaker, measuring cylinder, glass rod, dropper

(e) Procedure:1. 10 cm3 of latex is poured into a beaker.2. ethanoic acid is added into the beaker using a dropper.3. The mixture is stirred using glass rod.4. The beaker is left aside.5. Experiment is repeated using ammonia solution to replace ethanoic acid.6. The observation is recorded.


Mixture Observation Latex + ethanoic acidLatex + ammonia solution

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TOPIC : RATE OF REACTION

20. Building in industrial areas are more corroded than those in housing areas. This is because the concentration of acid in rain water is higher in industrial areas.Referring to the situation above, plan a laboratory experiment to investigate the effect of concentration on the rate of reaction between a named acid and a named metal.

(a) Statement of problem:Does the increases in the concentration acid increases the rate of reaction? //How does the concentration of acid affect the rate of reaction?

(b) Variable:Manipulated : concentration of hydrochloric acid.Responding : rate of reactionFixed : volume of hydrochloric acid / mass of zinc

(c) Hypothesis :The higher the concentration of hydrochloric acid the higher the rate of reaction.

(d) Materials : hydrochloric acid, 0.5 mol dm-3 , zinc powder. Apparatus : stopwatch, conical flask, beaker,

(e) Procedure:1. 25 cm3 hydrochloric acid is measured using measuring cylinder and poured into a beaker2. a spatula of zinc powder is put into the beaker.3. Stopwatch is started immediately.4. The mixture in the conical flask is swirled

5. Time is recorded for all zinc dissolve. 6. The experiment is repeated by using different concentarion of hydrochloric acid.


Concentration of hydrochloric acid, mol dm-3

Time for all zinc dissolve, s

1.00.50.1

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21. Aim: to investigate effect of catalyst on the rate of decomposition hydrogen peroxide.

Problem statement: How does a catalyst affect the rate of decomposition hydrogen peroxide?

Hypothesis: manganese (IV) oxide, MnO2 increases the rate of decomposition of hydrogen peroxide

Variables:

Manipulated : presence of manganese (IV) oxide (MnO2)Responding : rate of reactionFixed : concentration of H2O2 // initial temperature of H2O2 solution.

Apparatus: test tube, 10 cm3 measuring cylinder, test tube rack, spatula.Materials: (5-10) – volume of H2O2 solution, manganese (IV) oxide (MnO2) powder, wooden splinter

Procedures:1. Label two test tube as A and B2. Using a measuring cylinder measure 5 cm3 of 20 – volume of H2O2 solution and pour

into test tube A.3. Add ½ spatula (0.1-1.0 g) of manganese (IV) oxide powder into test tube A.4. Shake the test tube.5. Immediately place a glowing splinter into the test tube.6. Observe and record the changes.7. Repeat step (2 - 6) // he same procedure for test tube B without MnO2

Tabulation of data

Test tube ObservationA// presence of manganese (IV) oxide// catalyst B// with manganese (IV) oxide // catalyst

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Referring to the situation above, plan a laboratory experiment to investigate the effect of concentration or catalyst on the rate of reaction between a named acid and a named metal.

22. (i) Problem statement:How does concentration of acid affect the rate of reaction?

Variables:Manipulated variable : Concentration of acid (HCl)Responding variable : Rate of reactionConstant variable : Volume of acid //mass of metal

Hypothesis: The higher the concentration of acid (HCl) , the higher the rate of reaction.

Materials Zinc, (hydrochloric acid) [0.5 – 2.0] mol dm-3 , distilled water

ApparatusConical flask, measuring cylinder, stopper, delivery tube, basin, retort stand, burette, and stopwatch.

Procedure:1. A burette is filled with water and inverted into a basin of water. The initial burette

reading is recorded2. (50-100) cm3 of acid [0.5 – 2.0] mol dm-3 acid is measured and poured into a conical

flask.3. 2 g of zinc powder is added into conical flask4. The conical flask is closed immediately.5. At the same time, the stopwatch is started.6. The burette readings at intervals of 30 seconds are recorded until reaction stops.7. The experiment is repeated using the same volume of acid with different concentration.

Tabulation of data:

Time(s) 0 30 60 90 120 150 180 210 240

270 300

Burette Reading(cm3)

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Metal reacts with acid to form salt and hydrogen gas.


23.(ii) Problem statement:Does the presence of catalyst, copper(II) sulphate, increase the rate of reaction?

Variable:Manipulated variable : Catalyst // copper(II) sulphateResponding variable : Rate of reactionConstant variable : Volume and concentration of acid // mass of metal

Hypothesis:The presence of catalyst, copper(II) sulphate , increase the rate of reaction.

Materials Zinc powder, copper(II)sulphate solution, water, acid [0.5 – 1.0] mol dm-3

ApparatusConical flask cm3, measuring cylinder, stopper with delivery tube, basin, retort stand, burette, stopwatch.

Procedure:

1. A burette is filled with water and inverted into a basin of water. The initial burette reading is recorded

2. (50-100) cm3 of acid [0.5 – 1.0] mol dm-3 acid is measured and poured into a conical flask.

3. 5 cm3 of acid 0.5 mol dm-3 copper(II)sulphate solution is added into conical flask4. 2 g of zinc powder is added into conical flask5. The conical flask is closed immediately.6. At the same time, the stopwatch is started..7. The burette readings at intervals of 30 seconds are recorded until reaction stops.8. The experiment is repeated without adding copper(II) sulphate solution

Time(s) 0 30 60 90 120 150 180 210 240

270 300

Burette Reading(cm3)Volume of gas(cm3)

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TOPIC: REDOX

24. The rusting of iron can be affected by the present of other metal that is in contact with iron. Plan a laboratory experiment to investigate the effect of metal on the rusting of iron.

(a) Aim:To investigate the effect of different types of metals in contact with iron on the rusting.

Statement of problem:How does different type of metals in contact with iron affect rusting?

(b) VariableManipulated : metals (Magnesium and Copper)

Responding : the rusting of ironFixed : iron nail, jelly solution mix with potassium hexacyanoferrate(III) and

Phenolphthalein.(c) Hypothesis:

When a more electropositive metal is in contact with iron, the metal inhibits rusting. When a less electropositive metal is in contact with iron, the metal speeds up rusting.

(d) Materials:Iron nail, magnesium, copper strips, jelly solution mix with potassium hexacyanoferrate(III) and phenolphthalein, sandpaper.

Apparatus: test tube, test tube rack.

(e) Procedure:

1. Clean iron nail, magnesium and copper strip with sand paper.2. Coil two iron nails tightly with magnesium and copper strip.3. Place the iron nails into separate test tubes.4. Pour the hot jelly solution mix with potassium hexacyanoferrate(III) and phenolphthalein into the test tubes.5. Keep the test tubes in a test tube rack and leave them aside for two days.6. Record the observation.


Pair of metal Observation Fe-MgFe-Cu

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25. Way to store metals in laboratory depends on their reactivity with oxygen. The reactivity of the metals is compared by observing how fast or how vigorous they react. Generally, the more vigorous a metal burns in oxygen, the more reactive the metal is.

Based on this idea, plan a laboratory experiment to investigate the reactivity of magnesium, copper, zinc and lead with oxygen.

Aim:To investigate the reactivity of magnesium, copper, zinc and lead with oxygen Variable:manipulated: magnesium, copper, zinc and leadresponding: reactivity with oxygenFixed : solid potassium manganate(VII)

Hypothesis: The higher the position of metal in reactivity series, the higher the reactivity of metal with oxygen.

Apparatus:Boiling tube, retort stand and clamp, Bunsen burner, spatula and forcepsMaterial:Magnesium, copper, zinc and lead powder, solid potassium manganate(VII), asbestos paper, glass wool.

Procedure:1. Put one spatula of potassium manganate(VII), KMnO4 , into a boiling tube.2. Push some glass wool into the boiling tube and clamp horizontally.3. Place one spatula magnesium powder on a piece of asbestos paper and put into the boiling tube.4. Heat magnesium powder strongly and then heat the solid KMnO4.5. Observe and record how vigorous the reaction.6. Repeat step 1 to 5 using copper, lead and zinc powder.

Tabulation of data:

Metal Vigour of reactionMagnesiumCopper Lead Zinc

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TOPIC: THERMOCHEMISTRY

26. Plan a laboratory experiment to compare the heat of neutralization between a named strong acid with sodium hydroxide solution and heat of neutralization between named weak acid with sodium hydroxide solution.

(a) Statement of problem:Does heat of neutralization between hydrochloric acid and sodium hydroxide solution is higher than heat of neutralization between ethanoic acid with sodium hydroxide solution?

(b) VariableManipulated : type of acids

Responding : heat of neutralizationFixed : volume and concentration of acid / volume and concentration of alkali

(c) Hypothesis : Reaction between hydrochloric acid and sodium hydroxide solution has

higher heat of neutralization than reaction between ethanoic acid with sodium hydroxide solution.

(d) Materials / Substances:Hydrochloric acid, 0.5 mol dm-3 and sodium hydroxide, 0.5 mol dm-3, ethanoic acid 0.5 mol dm-3

Apparatus : polystyrene cup, measuring cylinder, thermometer

(e) Procedure :

1. 50 cm3 of sodium hydroxide solution is measured and pour into a polystyrene cup.2. The initial temperature of the solution in measured and recorded.3. 50 cm3 of hydrochloric acid is measured and pour into a polystyrene cup.4. The initial temperature of the solution in measured and recorded.5. Hydrochloric acid is poured into the sodium hydroxide solution.6. The mixture is stirred using thermometer and the highest temperature is recorded.7. The experiment is repeated using ethanoic acid.

(f) Tabulation of dataAcid Hydrochloric acid Ethanoic acid

initial temperature NaOH, oCinitial temperature acid ,oChighest temperature of the mixer ,oChighest temperature of the mixer, oC

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27. Different type of alcohols produces different heat of combustions. When the number of carbon per molecule of alcohol increases the heat of combustion increases. Table shows the heat of combustion of ethanol, propanol and butanol.

Alcohol Molecular formula Heat of combustion/ kJ mol-1

Ethanol C2H5OH -1376Propanol C3H7OH -2016Butanol C4H9OH -2678

Plan a laboratory experiment to compare the heat of combustion of the alcohols.

The heat of combustion for alcohols

(a) Statement of problem:` Does a different type of alcohol have different heat of combustion //

How does the number of carbon atom per molecule of alcohol affect the heat of combustion?

(b) Manipulated variable: Different type of alcohols // Different alcohols such as ethanol, propanol and butanol.

Responding variable:Heat of combustion//Increase in temperature

Fixed variable: Volume of water // type of container/ size of container

(c) Hypothesis:When the number of carbon per molecule of alcohol increases, the heat of

combustion increases.

(d) Materials Methanol, Ethanol, propanol, butanol, water,.

Apparatuscopper can, spirit lamp, thermometer, weighing balance, wooden block, tripod stand, wind shield, measuring cylinder

(e) Procedure:1. [200 cm3] of water is poured into a [copper can].2. Initial temperature of the water is recorded.3. A spirit lamp is half filled with methanol.4. Weight the spirit lamp with ethanol and record the mass5. The spirit lamp is put under the copper can and ignites the wick immediately.6. The water is stirred and the flame is put off after the temperature has increased by 30oC. 7. The highest temperature of the water is recorded8. Immediately weight the spirit lamp and record the mass. 9. The experiment is repeated t by replacing ethanol with ethanol, propanol and butanol.

(

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Table


f) Tabulation of data:

Types of alcohols

Initial temperature/oC

Highest temperature/oC

Initial mass of spirit lamp/g

Final mass of spirit lamp/g

Methanol EthanolPropanolButanol

TOPIC: CHEMICALS FOR CONSUMERS

28. Diagram shows the set-up of apparatus used to investigate the cleansing action of a cleaning agent on a piece of cloth stained with oil.

Experiment Apparatus Observation

I Oil stained remains

IIOil stained remains

Diagram Based on the above diagram, plan one laboratory experiment to compare the effectiveness of cleaning agents A mad B on cleansing action in hard water.

(a) Aim: To compare the effectiveness of cleaning agents A and B on cleansing action in hard water.

(b) Variable:Manipulated variable: Cleaning agent A and B Responding variable: Effectiveness of cleansing actionFixed variable: Type of water//hard water

(c) Hypothesis Cleaning agent B is more effective than cleaning agent A in hard water

(d) Material: Hard water, cleaning agent A and B

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Apparatus:,2 beakers, 2 pieces of cloths stained with oil, galss rod

(e) Procedure:1. [50 - 200] cm3 of hard water is poured into a beaker2. Cleaning agent A is added into the beaker3. A piece of cloth stained with oil is immersed in the solution4. The cloth is shaken/rubbed/stirred5. Observation is recorded

6. Repeat steps 1 – 5 by using cleaning B .


Type of cleaning agent ObservationCleaning agent A Cleaning agent A

Example of operational definition:

Operational definition for

What is observed What you do

Rusting of iron Blue spots are formed When an iron is coiled with a less electropositive metal is immersed into hot jelly added with potassium hexacyanoferrate(III) solution

Coagulation of latex

White solid formed When acid is added to the latex

Reactivity of Group 1 elements

Its move vigorously on the water surface.

Brighter flame is formed.

When a metal which is lower in Group 1 is put in basin half filled water.

When a metal which is lower in Group 1 is burn and put into the gas jar filled with oxygen gas.

Precipitation of silver chloride

White solid formed. When silver nitrate solution is added to sodium chloride solution

Voltaic cell The needle of the voltmeter deflects/ voltmeter shows a reading.

When two different metals connected to voltmeter are dipped into an electrolyte

An acid Blue litmus paper turn red

When a blue litmus paper is dipped into a substance which is dissolved in water

Reactivity of halogen

The brighter flame produced/formed

When halogen gas is flow through the heated iron wool,

The hardness of alloy

Smaller dent produced When the weights of I kg is dropped at height of 60 cm to hit the ball bearing which is tape on the alloy block.

Rate of reaction time taken for `X~ mark to disappear from sight is shorter

When the higher the concentration sodium thiosulphate solution is added into sulphuric acid,.

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Technology

Planning paper 3