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Perkongsian Amalan Teknik Perkongsian Amalan Teknik Menjawab Soalan Chemistry Menjawab Soalan Chemistry

Paper 3 SPM (4541 / 3)Paper 3 SPM (4541 / 3)

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Format of Paper 4541 / 3Format of Paper 4541 / 3

► TimeTime ; 1hr 30 minutes; 1hr 30 minutes ► MarksMarks ; 50 marks; 50 marks

► (i) Construct Tested;(i) Construct Tested;

Science Process Skills (16 aspects)Science Process Skills (16 aspects)TaskTask ; answer all 2 or 3 questions in 1hr 30 min; answer all 2 or 3 questions in 1hr 30 minLevel of DifficultyLevel of Difficulty – L : M : H = 5:3:2 – L : M : H = 5:3:2

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(1) Structured questions (45 (1) Structured questions (45 minutes)minutes)

Making observation, inferencing, identifying Making observation, inferencing, identifying and controlling the variables, and controlling the variables, hypothesising, classifying, making hypothesising, classifying, making operational definition, reading operational definition, reading instruments / measurements, constructing instruments / measurements, constructing table, plotting graph, predicting, table, plotting graph, predicting, interpreting data.interpreting data.

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(2) Extended Response Item (45 (2) Extended Response Item (45 minutes)minutes)

►Stating aim / problem statement Stating aim / problem statement ((always aalways a question !),question !), hypothesis, listing the hypothesis, listing the variables, materials & apparatus, variables, materials & apparatus, writing the procedure, tabulation of writing the procedure, tabulation of data.data.

►((A diagram usually helps in this question though there is no A diagram usually helps in this question though there is no specific allocation of marks for diagram, because certain steps specific allocation of marks for diagram, because certain steps left out in the procedure write-up may be able to be inferred from left out in the procedure write-up may be able to be inferred from

the diagram)the diagram)))

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(ii) Scoring for item :(ii) Scoring for item :

3 marks – Excellent : The best response3 marks – Excellent : The best response

2 marks – Satisfactory : An average 2 marks – Satisfactory : An average responseresponse

1 mark – Weak : An inaccurate response1 mark – Weak : An inaccurate response

0 mark – No response or Wrong response0 mark – No response or Wrong response

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(B) Guide on Answering(B) Guide on Answering

► (i) Answering the Structured (i) Answering the Structured Questions:Questions: Quite similar to the structured questions Quite similar to the structured questions

in Section A of Chemistry Paper 2, but in Section A of Chemistry Paper 2, but emphasises on the process skills:emphasises on the process skills:

Recall the topic / sub-topic and Recall the topic / sub-topic and application of the concepts and theories application of the concepts and theories related to the question;related to the question;

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►(ii) Answering the Extended (ii) Answering the Extended Response Item (Designing / Response Item (Designing / Planning of experiment)Planning of experiment)

No need to give complete report ( as the No need to give complete report ( as the PEKA report) as this is only the planning PEKA report) as this is only the planning stage.stage.

Procedure is preferably written in the Procedure is preferably written in the active formactive form (although the passive form is (although the passive form is also accepted)also accepted)

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Normally the question requires :Normally the question requires :

(a)(a) Problem Statement / AimProblem Statement / Aim

(b)(b) All the variablesAll the variables

(c)(c) HypothesisHypothesis

(d)(d) List of materials and apparatusList of materials and apparatus

(e)(e) ProcedureProcedure

(f)(f) Tabulation of dataTabulation of data

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(C) GUIDE TO MARKING PAPER (C) GUIDE TO MARKING PAPER 4541/3 :4541/3 :

1.1. Bilingual answer / Mixed language is Bilingual answer / Mixed language is accepted. accepted. ( BM or BI only )( BM or BI only )

2.2. Grammatical errors are ignored.Grammatical errors are ignored.3.3. Avoid use of American spelling Avoid use of American spelling

system. system. (e.g. color, oxidize)(e.g. color, oxidize)

4.4. Wrong spelling – Wrong spelling – often ignored unless often ignored unless for technical terms e.g. alkane, covalent for technical terms e.g. alkane, covalent bonding, chlorine atom…….bonding, chlorine atom…….

5.5. Avoid using abbreviation. Avoid using abbreviation. 6.6. List of substances and apparatus.List of substances and apparatus.

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7. 7. Case when more than one answer is given.Case when more than one answer is given. e.g. a student gives 2 answers for e.g. a student gives 2 answers for

hypothesis, then the score awarded depends hypothesis, then the score awarded depends on the accuracy of both answerson the accuracy of both answers

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Hypothesis 1Hypothesis 1 Hypothesis 2Hypothesis 2 Score Score awardedawarded

33 22 22

33 11 22

33 00 22

11 22 11

00 11 11

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8. Making observation8. Making observation – In Paper 3, – In Paper 3, observation is drawn from observation is drawn from sight sight only ! only ! (NOT from all 5 senses like in Paper 2 !!)(NOT from all 5 senses like in Paper 2 !!)

e.g. reject ‘ beaker feels warm ’e.g. reject ‘ beaker feels warm ’ accept ‘ temperature rises ‘accept ‘ temperature rises ‘9.9. Graph sketching / plottingGraph sketching / plotting

Should show axes with arrowhead with Should show axes with arrowhead with correct labels, correct units & correct correct labels, correct units & correct shape (curve or line)shape (curve or line)

10. Diagrams for the set-up of apparatus 10. Diagrams for the set-up of apparatus – – not required but encouragednot required but encouraged

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11. Constructing a table :11. Constructing a table :title of heading be based on the terms used title of heading be based on the terms used in question : (e.g. question use ‘Initial in question : (e.g. question use ‘Initial

temperature’ , students cannot change it to temperature’ , students cannot change it to ‘ ‘starting / beginning temp’ )starting / beginning temp’ )12. Stating volume of a liquid and mass of a 12. Stating volume of a liquid and mass of a

solidsolid► the use of the words “the use of the words “amountamount” and “” and “quantity”quantity”

is rejected. is rejected. (e.g. Constant Variable : (e.g. Constant Variable : amountamount of HCL is the of HCL is the same – wrong ! Must say the volume & same – wrong ! Must say the volume & concentration of HCL is the same.concentration of HCL is the same. Rate of reaction is the same because the Rate of reaction is the same because the quantityquantity

of reactants used is the same – REJECT !! )of reactants used is the same – REJECT !! )

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13. Accuracy in taking measurements13. Accuracy in taking measurements► Degree of accuracy depends on the type and Degree of accuracy depends on the type and

calibration of instrument usedcalibration of instrument used► Able to give accuracy to Able to give accuracy to at least at least oneone decimal decimal

place is expected for score 3;place is expected for score 3;

14. Calculations14. Calculations► Formula should use commonly used symbols, Formula should use commonly used symbols,

e.g. : H = mce.g. : H = mcǿǿ► Correct units must be statedCorrect units must be stated► Steps must be shown clearlySteps must be shown clearly

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(D) Some Terms Markers Use(D) Some Terms Markers Use

a)a) ““wrong cancel right” (wcr)wrong cancel right” (wcr)

b)b) ““benefit of doubt” (bod)benefit of doubt” (bod)

c)c) ““error carried forward” (ecf)error carried forward” (ecf)

d)d) ““avoid double penalty” (adp)avoid double penalty” (adp)

e)e) Reject (r) and Accept (a)Reject (r) and Accept (a)

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(E) Popular topics in Paper 3 :(E) Popular topics in Paper 3 :

► questions are based on questions are based on activitiesactivities and experiment;and experiment;

Applications Applications of theories and of theories and concepts rather than memorisation;concepts rather than memorisation;

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1.1. Determination of empirical formula Determination of empirical formula of metal oxide. (Q1 – 2004)of metal oxide. (Q1 – 2004)

2.2. Change of state of matter : e.g. Change of state of matter : e.g. boiling point / freezing point of boiling point / freezing point of naphthalene naphthalene

(Q1 – 2005)(Q1 – 2005)

3.3. (a) Construction of reactivity series (a) Construction of reactivity series of metals towards oxygenof metals towards oxygen

(b) Reaction of Group 1 and Group (b) Reaction of Group 1 and Group 17 of PTE. (Q2 – 2004,2008)17 of PTE. (Q2 – 2004,2008)

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4.4. Electrochemistry Electrochemistry (a) Construction of ECS : Q2 – 2005(a) Construction of ECS : Q2 – 2005

(b) Chemical cell / Factor affecting (b) Chemical cell / Factor affecting voltage: Q2 – 2007voltage: Q2 – 2007

(c) Electrolysis cell / Application of (c) Electrolysis cell / Application of electrolysis ( extraction of reactive electrolysis ( extraction of reactive metals, electroplating & purification metals, electroplating & purification of metal factors ) and factors of metal factors ) and factors affecting selective discharge of ions.affecting selective discharge of ions.

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5.5. Comparing physical or chemical Comparing physical or chemical properties of :properties of :

(i) an alloy-pure metal, (i) an alloy-pure metal,

(Q3 – 2003, Q3a – 2005)(Q3 – 2003, Q3a – 2005)

(ii) vulcanized rubber – natural (ii) vulcanized rubber – natural rubber, rubber,

(Q2 – 2006)(Q2 – 2006)

(iii) hydrocarbons – relating RMM (iii) hydrocarbons – relating RMM and physical properties.and physical properties.

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6.6. Acids & Bases And SaltsAcids & Bases And Salts

(a) role of water in showing acidity & (a) role of water in showing acidity & alkalinityalkalinity

(b) titration(b) titration

(c) qualitative analysis of cations & (c) qualitative analysis of cations & anionsanions

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7.7. Preparation ofPreparation of

(a) soluble salts of potassium, (a) soluble salts of potassium, sodium and ammonium.sodium and ammonium.

(b) other soluble salts.(b) other soluble salts.

(c) insoluble salts.(c) insoluble salts.

(d) continuous variation method (d) continuous variation method

(Q2 – 2003)(Q2 – 2003)

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8.8. Rates of reactions – determination Rates of reactions – determination from graph and calculation from graph and calculation

a)a) Effect of concentration: (Q3b – 2005)Effect of concentration: (Q3b – 2005)

b)b) Effect of temperature; (Q1 – 2003)Effect of temperature; (Q1 – 2003)

c)c) Effect of total surface area:Effect of total surface area:

d)d) Effect of catalyst:Effect of catalyst:

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9.9. Preparation & properties of esters Preparation & properties of esters (esterification). (Q3 – 2004)(esterification). (Q3 – 2004)

10.10. Redox Redox

a)a) rusting : Q3a – 2003rusting : Q3a – 2003

b)b) Effect of another metal an rustingEffect of another metal an rusting

c)c) Conversion of iron(II) and iron(III) Conversion of iron(II) and iron(III) ions, redox cellions, redox cell

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11.11. (a) Thermochemistry : Q1 – 2007(a) Thermochemistry : Q1 – 2007

(b) Heats of reaction :(b) Heats of reaction :

(i) precipitation(i) precipitation

(ii) displacement(ii) displacement

(iii) neutralisation – Q1 – (iii) neutralisation – Q1 – 20062006

(iv) combustion(iv) combustion

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12. (a) Preparation of soap12. (a) Preparation of soap

12.(b) Comparing effectiveness 12.(b) Comparing effectiveness of different detergentsof different detergents

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Paper 3Paper 3

►All questions are based on what the All questions are based on what the students have studied in the syllabusstudents have studied in the syllabus

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Decimal place …Decimal place …

►Burette Burette 2 decimal places 2 decimal places

25.00 cm25.00 cm33 / 0.00 cm / 0.00 cm33

►Thermometer / stopwatchThermometer / stopwatch one decimal placeone decimal place 25.0 25.0 ooC / 3.5 sC / 3.5 s

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Variables :Variables :

►State only one variable for controlled / State only one variable for controlled / fixed variablefixed variable

► If state more than one variables, one If state more than one variables, one of the answers is wrong, then the of the answers is wrong, then the wrong will cancel the right (wcr wrong will cancel the right (wcr effect !)effect !)

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Skills that will be evaluated in Paper Skills that will be evaluated in Paper 33 (Structure) (Structure)

1.1. ObservationObservation2.2. ClassifyingClassifying3.3. Measuring and Using NumbersMeasuring and Using Numbers4.4. Making inferenceMaking inference5.5. CommunicatingCommunicating6.6. Using SpaceUsing Space and and Time RelationshipTime Relationship7.7. Interpreting DataInterpreting Data8.8. Defining OperationallyDefining Operationally9.9. Controlling VariablesControlling Variables10.10.Making hypothesisMaking hypothesis11.11.PredictingPredicting

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Plan / Design an experimentPlan / Design an experiment

►Problem statement (always a ? Problem statement (always a ? Statement)Statement)

►Hypothesis (Hypothesis (can be a positive or can be a positive or negative hypothesisnegative hypothesis))

► Identifying and controlling variables. Identifying and controlling variables. ►Suitable apparatus and materialSuitable apparatus and material►ProceduresProcedures►Result (Tabulating data) – Result (Tabulating data) – Don’t fillDon’t fill in in

any data because u are planning an any data because u are planning an experimentexperiment

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