TASK 1

CHEMISTRY WORKSHOP : FOR MASTERING PAPER 3 AND

SCORE A1

Diagram shows two electrolytic cells.

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(a) State three different observations and the corresponding inferences in the table below. The observations should not include the colour change of the electrolyte

Observation InferenceÖ Colourless Gas bubbles/ bubbles release at anode of cell I (gelembung gas ) Ö Effervescences occur at anode of cell I X Air bubbles is release /buih

Oxygen gas is produced // (hydroxide ion)/OH- discharge

Ö Brown solid is deposited at cathode of cell 1 and II/ Ö Brown deposit formed at cathode of cell 1 and II/ Ö Cathode become thickerÖ Copper become thickerÖ Mass of cathode/copper increase X Brown precipitate formed X Electrode change shape / expand

Copper is formed //(copper ion)/Cu 2+ discharged

Ö Copper anode become thinner Ö Mass of copper anode decreaseX carbon electrode become thinner

Copper ions are produce // copper ionises

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(b) State one hypothesis for this experiment

MV – type of electrode//copper or carbon electrodes RV – product formed at anode Direction - difference 1.When different type of electrode used, different product formed at anode // -3m2.When copper electrodes used instead of carbon electrodes, different product formed at anode -3m3. Copper/ carbon produce different product -2m ( no Direction)

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(c) Based on the experiment complete the table below

Name of variables Action to be taken(i) Manipulated variableType of electrodes // carbon and copper // type of anode or cathode(X –type of metal)

(i) The way to manipulate variableReplace/change carbon electrode with copper electrode

(ii) Responding variableProduct at the anode//Product at the electrolysis//

(ii) What to observe in the responding variableObserve the product at anode

(iii) Fixed variableType of solution/electrolyte//copper(II) sulphate solution//Concentration of solution X – volume of electrolyte

(iii) The way to maintain the fixed variable…Use same solution as electrolyte Use same concentration of solution

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(d) Classify the solutions

Solution that produced gas at anode when electrolysed

Solution that does not produced gas at anode when electrolysed

Sodium hydroxideNitric acid

Potassium iodide

(e) In the electrolytic cell I, the colour of the solution changes from dark blue to light blue. In electrolytic cell II, there is no change of colour in the solution.

Explain the difference.

Cell 1 : The concentration of copper(II) ion, Cu 2+ decrease // Cell 2 : The concentration of copper(II) ion Cu 2+ remainunchanged( if use “ amount “ of Coppper(II) ion // correct half cell equation // not name ion/solution -score 2)

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(f) (i) labeled diagram / set up apparatus for electroplating of iron key with silver Anode : Cathode : Electrolyte :

Label // Shaded the solution –dash

ii. What will happened to the iron key after electrolysed for 20 minutes size / mass of key increase // the surface of key is plated by shiny grey solid

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TASK 3 : Plan an experiment for each questions. Make sure your explanation should include all the followings:-

1. Aim2. Problem statement3. Hypothesis (relate manipulated variables with

responding variables)4. All the variables (and method how you

manipulated, responding and controlled the variables)

5. List of substances and apparatus6. Procedure7. Tabulation of data

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Questions 1

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1. Aim :

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To investigate the relationship between the concentration of nitric acid and pH value2. Problem statement What is the relationship between the concentration of acid/ H+ and pH value? // Does the pH changes when the concentration of acid/H+ changes ? // Does the pH increase when the concentration of acid/H+ decreases ? Does the pH decrease when the concentration of acid/H+ increases ?3. Hypothesis The higher the concentration of acid/ H+ , the lower the pH value ( 3m) The lower the concentration of acid/ H+ , the higher the pH value ( 3m) The higher the concentration of acid/ H+ , the higher the

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pH value ( 3m) - incorrect direction sometime accepted The higher the concentration of acid/ H+ , will change/ affect pH value ( 2m) - no direction for RV Concentration of acid affect the pH value ( 1m) no direction for MV and RV

4. Variables Manipulated : concentration of acid // molarity // (state all the concentration of acid + unit) Responding : pH value // Colour of pH paper // colour of universal indicator Constant : type of acid // nitric acid5. Material and apparatus Materials : 0.1 mol dm-3, 0.01 mol dm-3,0.001 mol dm-3 0.0001 mol dm-3 nitric acid Apparatus : pH meter ( pH paper / universal indicator), beaker ( any suitable container )

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6. Procedure 1. (20-100 cm3) 0.1 mol dm-3 is poured into a beaker 2. Dip / Immerse the pH meter/ pH paper is into the acid solution// Put in a few drops( 1-5 drops) of universal indicator into acid solution 3. Record the pH value 4. Repeat step 1 using to 3 / experiment using 0.01 moldm-3,0.001 mol dm-3 and 0.0001 mol dm-3 nitric acid

7. Tabulation of dataConcentration of acid/ mol dm-3

pH value ( match correct RV in 3(b)

0.10.01

0.0010.0001

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Question 2

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1. Aim15

To investigate the how the distance between a pair of metals in ECS affect the voltage.

2. Problem statementScore 3 How does the distance between a pair of metal/ two metals in the ECS affect the voltage ? // Does the voltage increase when two metals are further apart in ECS ? Score 2Does the difference in the distance of two metals affect the voltage ?( Ö position/distance ,, pair of metals voltage)( X ECS )Does the the difference in the distance of metal in ECS affect the voltage ?(Ö position/distance , ECS, voltage)(X pair of metals )

3. VariablesMV : pairs of metals // pairs of electrode( if use : type of metal // distance between metal pair(*) // position of element

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score 2)RV: voltage/ voltmeter reading/potential differenceCV : electrolyte/ concentration of electrolyte/ the metals as positive /negative terminal

4. HypothesisThe further the distance between the pair of metal in ECS, the voltage become greaterScore 2The distance between the pair of metal in ECS influences the voltageÖ - relate MV to RV but X-direction for both MV and RVThe greater the voltage value, the further the position of metal in ECSÖ -direction for both MV and RV X -relate MV to RV but in opposite direction

5. List of materials and apparatusMaterials : aluminium, zinc, copper, copper(II) sulphate solution, sand paper

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Apparatus : voltmeter, beaker,wires,Can deduce from “ set-up apparatus/labelled diagram and procedure to complete list of material and apparatus but limited to 2 things

6. Procedure 1. Add/ Pour / Fill the electrolyte into container 2. Clean the metal strip with sandpaper 3. Dip / Immerse /Put the metals into the electrolyte

2.Connect the metals to the voltmeter // 3.complete the circuit

5. Record / take the voltmeter reading 6. Repeat step 1- 5 by substituitng one metal for another metalScore 3 – Able to state step 1- step 6Score 2 – Able to state step 1/3 , step 5 and step 6Score 1 – Able to state step 1/3 , only

4. Tabulation of Data 1. Correct heading for MV ( with unit if related) 2. Examples of MV 3. Correct heading for RV ( with unit )

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4. Tables (2x3 or 3x2 ) / line for table

Pair of metals Voltage, V Aluminium and Copper

Zinc and copper

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Question 3

You are given some iron nails, magnesium ribbon and copper strip.With reference to the above statement, plan a laboratory experiment to investigate the effect of other metals on the rusting of iron.

1. Aim

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A more electropositive metal acts as sacrificial metal which itself corrodes

to protect iron from rusting

To investigate the effect of other metals on the rusting of iron2. Problem statement What is the effect of other metals on the rusting of iron ?3. Hypothesis When a more electropositive metal is in contact with iron, the metal inhibit rusting // When a less electropositive metal is in contact with iron, the metal speed up rusting ( reactive metal – score 2)4. Variables Manipulated : types of metals // magnesium and copper Responding : Rusting of iron // intensity /presence of blue/pink colour Constant : Iron nails, temperature5. Material and Apparatus Materials : three iron nails, magnesium strip, copper strip,

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Hot agar/jelly solution mixed with potassium hexacyanoferrate(III) solution and phenolphthalein indicator, sand paper Apparatus : Three test tubes, test tube rack

6. Procedure 1. Clean magnesium strip and copper strip with sandpaper 2. Coil the metal strips around the iron nails and put the coil and uncoiled nail in different test tubes

3. Pour the equal volume of hot agar-agar solution has been mixed with with potassium hexacyanoferrate(III) solution and phenolphthalein indicator 4. Leave the test tubes aside for 1-2 days 5. Compare the intensity of the blue and pink colouration 6. Record your observations

7. Tabulation of data

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Test tube A

(nail +magnesium)

B(nail + copper)

CNail only

Intensity of blue colourIntensity of pink colourInference

An experiment is carried out to determine the heat of combustion of four alcohols, methanol, ethanol,propanol, and butanol. The initial mass of lamp mass of lamp containing alcohol is measured after burning. 200 cm3 of water is then heated with alcohol in the spirit lamp until the temperature rises by 30 C. The final mass of lamp containing alcohol is measured again after burning

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Variable 1. Manipulated : type of alcohol // methanol, ethanol,propanol, and butanol.2. Responding : Heat of combustion3. Constant :

NO

EXPERIMENT FOR FORM 4 GROU

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P

1. Melting and freezing point for naphthalene/acetamide

2. Reactivity of Group 1 (water, oxygen, halogens)3. Reactivity of Group 17 (Group 1, Iron and NaOH)4. Empirical formulae for MgO5. Empirical formulae for CuO6. Properties of Ionic And Covalent Compound7. Classify substances into electrolyte and non-

electrolyte8. Electrolysis for molten compound 9. Electrolysis based on factor of concentration

(others than acids)10.

Electrolysis based on factor of position in the electrochemical series

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Electrolysis based on factor of type of electrode

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Electrolysis for dilute acid (H2SO4 and HCl)

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Electrolysis for concentrate acid (H2SO4 and HCl)

14.

Purify copper and silver (2 sub experiment)

15.

Electroplate copper and silver (2 sub experiment)

16 Aluminium extraction

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.17.

Chemical cell (using salt bridge)- MgNO3 and CuSO4

18.

Chemical cell (using porous pot)- AgNO3 and ZnSO4

19.

Displacement reaction using CuSO4 as a electrolyte and different strips metal (Mg, Al, Zn, Fe. Sn, Pb, Ag)

20.

Displacement reaction using CuSO4 as a electrolyte and different strips metal (Mg, Al, Zn, Fe. Sn, Pb, Ag) to construct a electrochemical cell based on their potential reading

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Role of water in showing the properties of acid (also use organic solvent to compare)

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Preparation for standard solution ( for NaOH-alkali)

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Dilution for concentration acid (HCl)

24.

Relationship between pH values with molarity of acid and alkali solution)

25.

End point in titration

26.

Ionic equation for the formation of lead (II) chromate (VI)

27.

Preparation for soluble salt (acid + bases)

28 Preparation for soluble salt (acid + carbonates

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. metal)29.

Preparation for soluble salt (acid + reactive metal)

30.

Preparation for soluble salt (acid + oxide metal)

31.

Preparation for insoluble salt

32.

Solubility of nitrate, sulphate, carbonate and chloride salts

33.

Alloy and pure metal

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The effectiveness of a cleansing action of a soap and detergent

NO

EXPERIMENT FOR FORM 5 GROUP

1. Rate of reaction – Factor : size2. Rate of reaction – Factor : Temperature3. Rate of reaction – Factor : Concentration4. Rate of reaction – Factor : Catalyst5. Properties of alkanes and alkenes6. Preparation of ethanol by fermentation7. Chemical properties of ethanol8. Chemical properties of ethanoic acids9. Preparation of ester10.

Investigate the physical properties of ester

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11.

Preparation of vulcanized rubber

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Comparison the elasticity of vulcanized and unvulcanized rubber

13.

Change Fe2+ to Fe3+ and Fe3+ to Fe2+

14.

Displacement of halogens

15.

Transfer of electrons at a distance : KMnO4 / Cl2

16.

Transfer of electrons at a distance : K2Cr2O7 / Br2

17.

Transfer of electrons at a distance : SnCl4 / FeSO4

18.

Transfer of electrons at a distance : KCl / Fe2(SO4)3

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Transfer of electrons at a distance : KMnO4 / Cl2

20.

Transfer of electrons at a distance : ZnSO4/ CuSO4

21.

Reactivity of metals with oxygen

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The position of carbon in Reactivity Series

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The position of hydrogen in Reactivity Series

24 Rusting process

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.25.

Thermochemistry : Heat of Neutralization

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Thermochemistry : Heat of Precipitation

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Thermochemistry : Heat of Displacement

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Thermochemistry : Heat of Combustion

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Preparation of soaps

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The effectiveness of a cleansing action of a soap and detergent

-A1 FOR CHEMISTRY-

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