kimia p3 sbp mid year spm 2008

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    Untuk Kegunaan Pemeriksa

    Soalan MarkahPenuh

    MarkahDiperoleh

    1 18

    2 15

    3 17

    JUMLAH 50

    Nama : ... Kelas : ...

    SEKTOR SEKOLAH BERASRAMA PENUHKEMENTERIAN PELAJARAN MALAYSIA

    _______________________________________________

    PEPERIKSAAN PERTENGAHAN TAHUN

    2008

    KIMIA

    KERTAS 3

    Satu jam Tiga Puluh Minit

    JANGAN BUKA KERTAS SOALAN INI SEHINGGA DIBERITAHU

    1. Tuliskan nama dan tingkatan pada

    ruang yang disediakan.2. Calon dikehendaki membaca maklumat

    di halaman 2.

    Kertas soalan ini mengandungi 9 halaman bercetak

    4541/3KimiaKertas 3Mei20081 Jam

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    SULIT

    4541/3 SULIT2

    INFORMATION FOR CANDIDATES

    1. This question paper consists of three questions. Answer all questions.

    2. Write your answers for Question 1 and Question 2 in the spaces provided in the question

    paper..3. Show your working. It may help you to get marks.

    4. If you wish to cancel any answer, neatly cross out the answer.

    5. The diagrams in the questions are not drawn to scale unless stated.

    6. Marks allocated for each question or part question are shown in brackets.

    7. The time suggested to answer Question 1 and Question 2 is 45 minutes and Question 3 is

    45 minutes .

    8. You may use a non-programmable scientific calculator.

    9. Hand in this question paper at the end of the examination.

    Marks awarded:Mark Description

    3 Excellent : The best response

    2 Satisfactory : An average response

    1 Weak : An inaccurate response

    0 No response or wrong response

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    SULIT

    4541/3 SULIT3

    1. An experiment was conducted to find out the effect of temperature on the rate of reaction.

    50 cm 3 of sodium thiosulphate solution 0.2 mol dm -3 at 30 oC was put into a 150 cm 3

    conical flask. Then the conical flask was placed on an X sign on a piece of white paper.

    5 cm 3 of sulphuric acid 1.0 mol dm -3 was added to the sodium thiosulphate solution and

    shaken. At the same time, the stop watch was started. The stop watch was stopped as

    soon as the X sign was no longer visible. The same steps of the experiment were

    repeated for sodium thiosulphate solution which was heated to 35 oC, 40 oC, 45 oC and

    50oC.

    Diagram 1 shows the reading of the stop watch for each of the reaction at different

    temperatures.

    (a) Record the time for each reaction in the spaces provided in Diagram 1.

    [3 marks]

    Time , t 1

    at 30o

    CTime , t 2 at 35 o C

    Time , t 3 at 40 o C

    Time , t 4 at 45 o C Time , t 5

    at 50 o C

    Diagram 1

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    SULIT

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    (b) State one observation in this experiment.

    [3 marks]

    (c) Construct a table and record temperature, time, and 1/ time for this experiment.

    [3 marks]

    (d) (i) Plot a graph of temperature of sodium thiosulphate solutions against 1/ time.[3 marks]

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    SULIT

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    Graph of temperature against 1/ time

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    SULIT

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    (ii) Based on the graph in (d) (i), state the relationship between the rate of reactionand temperature.

    .

    [3 marks]

    (e) Complete the Table 1.1 based on the above experiment.

    Type of variable Action that needs to be taken

    (i) Manipulated variable:

    .

    .

    .

    The way to manipulate the variable:

    ...

    ...

    ...

    (ii) Responding variable:

    .

    .

    .

    What to observe in the responding variable:

    ...

    ...

    ...

    (iii) Fixed variable:

    .

    ..

    The way to maintain the fixed variable:

    ...

    ......

    [3 marks]Table 1.1

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    SULIT

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    2. The pupil carried out an experiment to construct the electrochemical series of metalsusing 0.5 mol dm -3 copper(II) sulphate solution as the electrolyte.

    The set up of apparatus of this experiment is shown in Diagram 2.

    Diagram 2

    Table 2 shows the voltmeter readings of each cell that obtained from the pairs of metals.

    Experiment Pair of metals Reading of voltmeter

    ( V )Y electrode Positive electrode

    I Magnesium Copper 2.70

    II Iron Copper 0.78

    III Zinc Copper 1.10

    IV Lead Copper 0.45

    Table 2

    (a) Based on experiment I,

    (i) Write the overall ionic equation.

    [ 3 marks ]

    Copper(II) sulphate solution

    YCu

    V

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    SULIT

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    (ii) Based on the change in size that you observed at the magnesium electrode after30 minutes, state the inference.

    [ 3 marks ]

    (b) Predict the voltmeter readings of the cell when zinc and lead metals are used.

    [ 3 marks ]

    (c) Based on Table 2, arrange the metals zinc, iron, magnesium, lead and copperin an ascending order based of their tendency to release electron.

    [ 3 marks ]

    (d) Give the operational definition of the above reaction.

    [ 3 marks ]

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    SULIT

    4541/3 SULIT9

    3. Diagram 3 shows two beakers containing colourless solution labelled A and B.

    Diagram 3

    You are told that the two colourless solutions are calcium nitrate and magnesium nitrate. You are

    required to label correctly the name of each solution in the containers.

    Design an experiment to identify which is calcium nitrate and which is magnesium nitrate

    solution by using aqueous of ammonia solution as a reagent.

    Your answer should include the following:

    (a) Problem statement(b) Hypothesis

    (c) All variables

    (d) List of materials and apparatus

    (e) Procedure

    (f) Tabulation of data

    [17 marks]

    END OF QUESTION PAPER

    Beaker A Beaker B

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    1

    SULIT 4541/1/2/34541ChemistryMarking SchemeMei

    2008

    BAHAGIAN SEKOLAHKEMENTERIAN PELAJARAN MALAYSIA

    ______________________________________________PEPERIKSAAN PERTENGAHAN TAHUN 2008

    FORM 5 CHEMISTRY

    MARKING SCHEME FOR PAPER 1, 2 AND PAPER 3

    Peraturan pemarkahan ini mengandungi halaman bercetak.

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    2

    PAPER 1

    1 B 21 D 41 D2 C 22 D 42 B

    3 B 23 B 43 D4 C 24 A 44 C5 D 25 C 45 B6 A 26 A 46 A7 B 27 D 47 B8 A 28 A 48 D9 D 29 C 49 C

    10 D 30 A 50 B11 D 31 A12 C 32 B

    13 A 33 D14 A 34 A15 C 35 C16 B 36 A17 C 37 D18 C 38 B19 C 39 B20 C 40 D

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    3

    PAPER 2-SECTION A

    No. Rubric Mark

    1 a

    b (i)

    (ii)

    c

    d

    e (i)

    (ii)

    (iii)

    GHas stable /octet electron arrangement//8 valence electron

    2A + 2H 2O 2AOH + H 2

    Use a small pieces//use a forcep// use a google

    G,E,D, A,J,L

    Has same valence electron// valence electron is 1

    DE 2 r : E2D

    [can draw the diagram of electron arrangement correctly]

    - Correct structure of atoms

    - Correct ratio of atoms=1:2

    Has (neutral ) molecule

    TOTAL

    11

    1

    1

    1

    1

    1

    2

    1

    10

    2 a

    b(i)

    (ii)

    c

    d

    e (i)

    (ii)

    (iii)

    T1

    PQ: solid + liquid

    RS: liquid

    Heat energy absorbed

    is used to overcome the forces of attraction between particles

    // Heat is absorbed to overcome the intermolecular forces

    r: ion/atom

    (1+1)

    The particles / molecules move faster

    Iodine/I 2 //napthalene/C 10H8

    Copper/ Cu

    Ion

    Diffusion

    TOTAL

    1

    1

    1

    1

    1

    1

    1

    1

    1

    1

    10

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    4

    3 a (i)

    (ii)

    b (i)

    (ii)

    (iii)

    c (i)

    (ii)

    d

    3H 2 + N 2 2NH 3

    ( Extract from ) air

    Neutralization

    H2SO 4+ 2NH 3 (NH 4)2SO 4

    //H2SO 4+ 2NH 4OH (NH 4)2SO 4 + H2O

    Fertilizer

    Tin

    In pure copper the layer of atom are easily slide over each

    other when external force is applied on them.

    The different size of foreign atoms in allloy are prevent the

    layers of atom from slide each other when external force is

    applied.

    TOTAL

    1

    1

    1

    1

    1

    1

    (1+1)

    1

    1

    10

    4 a

    b(i)

    (ii)

    1 Diagram of set up of apparatus complete and functional

    2 Label

    (Anode) impure copper and (cathode ) pure copper

    3 ( Electrolyte) copper (II) sulphate / copper (II) chloride // copper

    (II) nitrate solution

    a: chemical formula

    1 become thinner // decrease in mass

    2 become thicker // increase in mass

    1 ( Remain )unchanged

    2 Number of Cu 2+ ions produced at anode same as number of

    copper atoms produced at cathode // the rate of formation of Cu 2+

    1

    1

    1

    1

    1

    1

    Copper atomCopper atom

    Tin atom

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    5

    c (i)(ii)

    d

    ions at the anode is the same as the rate of discharge of Cu 2+ at

    cathode.

    (Anode ):Cu Cu 2+ + 2e

    (Cathode ): Cu 2+ + 2e Cu

    Electroplating of metals/ Extraction of reactive metals

    TOTAL

    1

    1

    1

    1

    10

    5 a

    b

    c (i)

    (ii)

    d

    2H 2O2 O2 + 2H 2O

    Number of mole of H 2O2 = 20 x 2/1000= 0.04

    2 mol of H 2O2 produce 1 mol of O 2 //

    Number of mole of O 2 = 0.04/2 = 0.02

    Volume, O 2 = 0.2 x 24dm 3 = 4.8 dm 3

    Rate of reaction in experiment II is higher than experiment I

    The concentration/number of molecule per unit volumeof

    hydrogen peroxide in II is higher

    The frequency of collision between H 2O2 molecule is higher

    The frequency of effective collision is higher

    Volume of gas/cm 3

    Time(s)

    Label Y axes and X axesCorrect curve and label I and II

    TOTAL

    1

    1

    1

    1

    1

    1

    1

    1

    11

    10

    II

    I

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    6

    6 a

    b (i)

    (ii)

    (iii)

    c (i)

    (ii)

    (iii)

    d (i)

    (ii)

    (iii)

    A compound that contain element of carbon and derive from living

    organisms.

    C2H4

    ethene

    double bond between carbon atoms

    (a: C=C )

    Acidified potassium manganat (VII) // Acidified potassium

    dicromate (VI)

    Oxidation

    Purple to colourless // orange to green

    C2H4 + H 2O C2H5OH

    Alcohol

    Temperature 300 oC // Pressure 60 atmosphere // concentrated

    phosphoric acid

    TOTAL

    1

    1

    1

    1

    1

    1

    1

    1

    1

    1

    10

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    7

    SECTION B

    No. Rubric Mark

    7 a (i)

    (ii)

    b

    Compound that form when non metal atom gain/receive/accept

    electron that release/lose/donate by metal atom to achieve stable

    /octet/duplet electron arrangemen

    Compound that form between non metal atom by sharing their

    valence electron to achieve stable/octet /duplet electron

    arrangement

    Between P and Q

    Atom X has 1 valence electron

    Atom X loses/donates/transfers 1 electrons to form X + ion //

    X X+ + e- and attain stable octet electron arrangement

    Atom Y has 7 valence electrons

    Atom gains/receives/accept 1 electron to formY - ion//

    Y + e- Y-

    attain the stable /octet electron arrangement

    The two oppositely-charged ions// the X + and Y - ion are

    bonded together by a strong electrostatic force

    To form a ionic compound with the formula XY// diagramn

    Max 7

    1

    1

    1

    1

    11

    1

    11

    X

    Y

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    8

    (ii)

    (iii)

    Between Y and Z

    Atom Z has 4 valence electrons and atom Y has 1 valence

    electrons

    One atom Z contributes 4 electrons and (each) atom Y

    contributes one electron for sharing .

    Atom Z shared 4 pairs of electron with 4 atoms Y

    to attain a octet /stable electron arrangement respectively

    diagram

    Magnesium oxide is an ionic compounds

    Strong electrostatic force of attraction exists between

    Mg 2+ and O 2 - //

    the oppositely-charged magnesium ions and oxide ions in

    Magnesium oxide are held together by strong ionic bonds

    A lot of heat energy // high of energy is required to break the

    strong forces

    Tetrachloromethane is a covalent compound

    Weak intermolecular forces //held together by weak (Van der

    Waals) force of attractions between molecule

    little heat energy //low energy is needed to overcome the

    weak forces

    1

    1

    111

    1

    1

    1

    1

    1

    1

    Z YY

    Y

    Y

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    9

    8 a

    b

    c(i)

    Empirical formula- Formula shows simplest ratio of atoms of each

    element in the compound

    Molecular formula- Formula shows actual number of atoms of

    each element in the compound

    Molecular Formula = ( Empirical formula )n= ( CH 2 )n

    Relative Molecular Mass ( CH 2 )n = 7012n + 2n= 7014n=70

    n=5

    Molecular Formula C 5H10

    1. Metal Z is cleaned using sand paper

    2. A crucible and its lid are weighed and the mass is recoded

    3. Metal Z is palced in the crucible. The crucible,lid and its

    content is weighed and the mass is recorded.

    4. The crucible with its content is heated strongly without

    lid.

    5. When metal Z start burn, the crucible is covered by its

    lid

    6. the covered is raise a little at intervals

    7. When there is no more reaction, the lid is removed and the

    crucible is heated strongly for a few minutes.

    8. Cool the crucible and weigh the crucible,its lid and its

    Content and record the mass.

    9. The process of heating, cooling and weighing is repeated

    until constant is obtained.

    10. (Precaution step );

    Close the crucible immediately to prevent loss of

    1

    1

    1

    11

    11

    1

    1

    1

    1

    1

    1

    1

    1

    TOTAL 20

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    10

    Element Z O

    Mass(g) 1.30 0.32

    mol 1.30/65=0.02 0.32/16=0.02

    Simplestratio

    1 1

    Empirical Formula ZO

    TOTAL

    1

    1

    1

    1

    1

    20

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    11

    PAPER2 SECTION C

    No Rubric Mark

    9 a

    b (i)

    (ii)

    c(i)

    Sample answer :Zn + HNO 3 Zn(NO 3)2 + H2O

    ZnCO 3 + HNO 3 Zn(NO 3)2 + H2O + CO 2

    ZnO + HNO 3 Zn(NO 3)2 + H2O

    Any two

    Methanoic acid partial ionizes in water

    produce low concentration of hydrogen ionGlacial ethanoic acid has (neutral) molecule

    Methanoic acid aqueous ionizes in water

    to produce free moving ion

    Procedure :

    1 100 cm 3 of 0.1 moldm -3 sulphuric acid is poured into a beaker

    and heated slowly.

    2 zinc carbonate is added into the sulphuric acid until in excess/nolonger dissolves.

    3 Stir the solution and filtered.

    4 The filtrate is poured into an evaporating dish and heat untilsaturated

    5 The hot saturated salt solution is allowed to cool

    6 The crystals formed are filtered out, rinsed with distilled water

    7 dried between sheets of filter paper.

    2

    1

    11

    1

    1

    1

    1

    1

    1

    1

    1

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    12

    (ii)

    d

    ZnCO 3 + H2SO 4 ZnSO 4 + H2O + CO 2

    Number of mole , H 2SO 4 = 0.1( 100 )/1000

    = 0.01

    1 mol of H 2SO 4 produce 1 mol of ZnSO 4

    Mole of ZnSO 4 = 0.01

    Mass of ZnSO 4 = 0.01 X 161

    = 16.1 g

    Sample answer :

    1 ammonium chloride as a fertilizer2 copper (II) sulphate as a pesticide

    3 hydrated calcium sulphate to make plaster casts4 sodium chloride food additiveAny 2 suitable anwers(1+1)

    TOTAL

    1

    1

    1

    1

    1

    1

    20

    10a (i)

    (ii)(iii)

    (iv)

    (v)

    catalyst

    esterification

    CH 3COOH + C 3H7OH CH 3COOC 3H7 + H2O

    Correct reactant

    Correct product

    Ethyl propanoate

    Sweet smell/fruity smell/fragrant smell

    //insoluble in water/soluble in organic solvent

    //colourless //less dense than water

    any two properties (1+1)

    1

    1

    1

    1

    2

    2

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    13

    b (i)

    (ii)

    Bacteria will produce lactic acid/H + ions which neutralize

    negatives charge of the protein membrane/ rubber molecules

    The rubber molecules will be collide with each other and

    cause protein membrane brokenRubber polymer are released and lump together

    Hydroxide ions/OH - from ammonia solution will neutralise

    H+ produced by acid

    The protein membrane remains negatively charged

    The rubber particles repel each others/ the rubber polymers

    cannot combine and coagulate

    The presence of cross-linkage of sulphur atoms between

    the rubber molecule

    When vulcanized rubber is stretched and release, the cross-

    linkage will pull the chain back to their original

    arrangement

    Diagram

    Improves the elasticity and strength of the rubber / make

    vulcanized rubbers more resistant to heat /organic solvent

    orResistant to oxidation :

    The presence of cross-linkage of sulphur atoms between

    the rubber molecule

    Diagram

    C=C in vulcanized rubber is less than C=C in the

    unvulcanized rubber,

    so vulcanize rubber is more resistant to oxidation

    TOTAL

    1

    1

    1

    1

    1

    1

    1

    1

    1

    1

    1

    1

    1

    1

    20

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    14

    PAPER 3

    1 (a) KK0503 Measuring and using numbersEXPLANATION SCORE

    [Able to write all the times with units accurately]

    Suggested answer:

    t 1 55.0 s, t 2 48.0 s , t 3 42.0 s , t 4 37.0 s , t 5 33.0 s

    3

    [Able to record all the times accurately but without units / no decimal place]t1 55.0 , t 2 48.0 , t 3 42.0 , t 4 37.0 , t 5 33.0 // // t1 55 s , t2 48.0 s , t 3 42 s, t 4 37s, t 5 33s

    2

    [Able to write at least 3 readings of the times accurately] 1

    No response given / wrong response 0

    1 (b) KK0501- ObservationEXPLANATION SCORE

    [Able to state the colour of sulphur and the rate of it is formed]Suggested answer:

    Pale / light yellow precipitate is slowly formed

    3

    [Able to state the colour of sulphur]Pale / light yellow precipitate is formed.

    2

    [Able to state the formation of precipitate]

    A precipitate is formed.

    1

    No response given / wrong response 0

    1 (c) KK0506 CommunicatingEXPLANATION SCORE

    [Able to construct a table correctly containing three labeled columns withcorrect units and record all the time and 1/time accurately ]

    Suggested answer:

    Temperature,o

    C

    30 35 40 45 50

    Time , s 55.0 48.0 42.0 37.0 33.01 / time , s -1 0.018 0.021 0.024 0.027 0.030

    3

    [Able to construct a table correctly containing three labeled columns withcorrect units and record all the time and 1/time but not accurately]

    2

    [Able to write at least 3 readings of the times accurately] 1

    No response given / wrong response 0

    1 (d) (i) KK0506 Communicating

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    EXPLANATION SCORE[Able to draw a graph accurately that consists of the following aspects]Suggested answer:

    1. Both axes labeled and units

    ( Y axis - temperature , X axis 1/ time )2. All points transferred correctly3. Uniform scale, graph size covers at least half of the graph paper.4. Straight line/ best fits drawn

    3

    [Able to draw a graph that consists of the following aspects]1. Both axes labeled / units

    ( Y axis - temperature , X axis 1/ time )2. At least three points transferred correctly3. Uniform scale, graph size covers at least half of the graph paper.4. Straight line/ best fits drawn

    2

    [Able to draw a graph that consists of the following aspects]1. Both axes labeled and units

    ( Y axis - temperature , X axis 1/ time )2. Draw a line

    1

    No response given / wrong response 0

    1(d)(ii) KK0509 To define OperationallyEXPLANATION SCORE

    [Able to interpret the relationship between the rate of reaction and thetemperature of sodium thiosulphate solution from graph accurately]Suggested answer:

    The rate of reaction is directly proportional to the temperature of sodiumthiosulphate solution // As the temperature of sodium thiosulphate increasesthe rate of reaction increases.

    3

    [Able to interpret the relationship between the rate of reaction and thetemperature of sodium thiosulphate solution from graph ]

    The rate of reaction is proportional to the temperature // the temperature is

    proportional to the rate of reaction // the rate of reaction increases when thetemperature increases.

    2

    [Able to state an idea of hypothesisThe temperature affects the rate of reaction.

    1

    No response given / wrong response 0

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    16

    30

    35

    40

    45

    50

    0.015 0.020 0.025 0.030X

    X

    X

    X

    X

    Temperature / o

    C

    1/time , s -1

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    17

    1(e) KK0510 - State variables

    EXPLANATION SCORE

    [Able to state three variables and three action to be taken]Suggested answer:

    Variable Action to be takenManipulated:Temperature

    Heat the sodium thiosulphatesolution at different temperature // Use different temperature.

    Responding:Rate of reaction / time taken for Xmarks to disappear from view.

    Record the time taken for X mark to disappear from view.

    Controlled :Concentration and volume of H 2SO 4,concentration and volume of sodiumthiosulphate solution, size of conicalflask.

    Use the same concentration andvolume of H 2SO 4 /sodiumthiosulphate solution // Use samesize conical flask.

    3

    [Able to state any two variables and any two action to be taken] 2

    [Able to state any one variables and any one action to be taken] 1

    No response given / wrong response 0

    2 (a) KK0506 Communicating EXPLAINATION SCORE[Able to write the correct overall ionic equation]Suggested answer:

    Mg + Cu 2+ Mg 2+ + Cu

    3

    Mg + CuSO 4 MgSO 4 + Cu 2Mg Mg 2+ + 2e // Cu 2+ + 2e Cu 1 No response given / wrong response 0

    2(a)(i) KK 0504 Making inferenceEXPLANATION SCORE

    [Able to state the correct inference]Suggested answer:

    Magnesium atom releases/donate/loses electrons to produce magnesium ion // Magnesium is corrode.

    3

    Magnesium becomes thinner // mass of magnesium decreases 2Magnesium dissolves 1 No response given / wrong response 0

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    18

    2(b) KK 0505 - PredictingEXPLANATION SCORE

    [Able to state the voltage value]

    0.65 V

    3

    0.63 0.64 V // 0.66 0.67 V 2< 0.64 V // > 0.67 V 1 No response given / wrong response 0

    2(c)KK 0508 Interpreting DataEXPLANATION SCORE

    [Able to arrange the position of all metals in an ascending order based ontendency to release electrons correctly]Copper > Lead > Iron > Zinc > Magnesium

    3

    [Able to arrange the position of all metals in descending order based ontendency to release electrons]Magnesium > Zinc > Iron > Lead > copper

    2

    [Able to arrange the position of at least four metals in ascending order based on tendency to release electrons correctly]

    1

    No response given / wrong response 0

    2(d) KK0509 Operational definitionEXPLANATION SCORE[Able to state the correct and complete operational definition]Suggested answer:

    The further the metal is from copper in the electrochemical series, the greateris their voltage reading. //

    3

    [Able to give incomplete relationship]Suggested answer:

    The further apart the metal is in the electrochemical series, the greater thepotential difference / voltage reading.

    2

    [Able to state an idea]Suggested answer:

    The position of metal influence the voltage reading // Type of metal influence the voltage reading.

    1

    No response given / wrong response 0

  • 8/14/2019 Kimia P3 SBP Mid Year SPM 2008

    28/30

    19

    3.(a) KK051021 Statement of problemEXPLANATION SCORE

    [Able to make a suitable statement of problem]

    Suggested answer:

    How to differentiate between magnesium nitrate solution and calcium nitratesolution // How to differentiate between magnesium ion and calcium ion

    3

    [Able to make a suitable aim]Suggested answer:

    To differentiate the presence of magnesium ion and calcium ion by usingaqueous ammonia solution.

    2

    [Able to state an idea of statement of problem or aim] 1

    No response given / wrong response 0

    3(b) KK051202 Stating hypothesisEXPLANATION SCORE

    [Able to state the relationship between manipulated variable and respondingvariable correctly]Suggested answer:

    If the addition of aqueous ammonia solution forms white precipitate which isinsoluble in excess ammonia aqueous solution, then the solution tested is

    magnesium nitrate. // If aqueous ammonia solution is added and no changeoccur then the solution tested is calcium nitrate.

    3

    [Able to state the relationship between manipulated variable and respondingvariable]

    2

    [Able to state an idea of the hypothesis] 1

    No response given / wrong response 0

    3 (c) KK051202 Stating variables

    EXPLANATION SCORE[Able to state all the three variables correctly]Suggested answer:

    Manipulated variable : magnesium nitrate and calcium nitrate // Mg 2+ and Ca 2+

    Responding variable: formation of white precipitateControlled variable : aqueous ammonia solution[Able to state any two of the variables correctly]

    [Able to state one of the variables correctly or state idea regarding variable]

    No response given / wrong response

  • 8/14/2019 Kimia P3 SBP Mid Year SPM 2008

    29/30

    20

    3(d) KK051205 List of substances and apparatusEXPLANATION SCORE

    [Able to state the list of substances and apparatus correctly and completely]

    Suggested answer:

    Test tube, dropper, test tube rack 0.5 mol dm -3 magnesium nitrate solution, 0.5 mol dm -3 calcium nitratesolution, aqueous ammonia solution.

    3

    [Able to state the list of substances and apparatus correctly but not completely]Suggested answer:

    Test tube0.5 mol dm -3 magnesium nitrate solution, 0.5 mol dm -3 calcium nitratesolution, aqueous ammonia solution.

    2

    [Able to state an idea about the list of substances and apparatus]Suggested answer:

    Test tubemagnesium nitrate, calcium nitrate

    1

    No response given / wrong response 0

    3(e) KK051204 Technique /Precedure

    EXPLANATION SCORE[Able to state a complete experimental procedure]Suggested answer:

    1. 2 cm 3 of solution A is poured into a test tube.2. A few drops of aqueous ammonia solution are added into the test tube

    using a dropper and the test tube is shaken well.3. If the precipitate is formed, aqueous ammonia solution is added

    continuously until no further change occurred / until excess4. The mixture is shaken well.5. The changes occur is recorded in a table.6. Steps 1 to 4 are repeated using solution B.

    3

    [Able to state a complete experimental procedure]1,2,3,4,5

    2

    [Able to state a complete experimental procedure]1,2,3,5

    1

    No response given / wrong response 0

  • 8/14/2019 Kimia P3 SBP Mid Year SPM 2008

    30/30

    3(f) Tabulation of dataEXPLANATION SCORE

    [Able to exhibit the tabulation of data correctly ]

    Reagent ObservationTest tube/Solution A Test tube/Solution B

    Aqueousammonia solution 3

    [Able to exhibit the tabulation of data less accurately ]

    Reagent Test tube /Solution A Test tube/Solution BAqueousammonia solution

    2

    [Able state an idea about the tabulation of data] 1

    No response given / wrong response 0

    END OF MARKING SCHEME