SULIT 4541/1/2/34541/1KimiaKertas 1Ogos2007

BAHAGIAN SEKOLAHKEMENTERIAN PELAJARAN MALAYSIA

______________________________________________PEPERIKSAAN PERCUBAAN SPM 2007

KIMIAPeraturan pemarkahan Kertas 1, 2 dan 3

Peraturan pemarkahan ini mengandungi halaman bercetak.

Kertas 1

1 A 21 B 41 A2 B 22 D 42 A3 A 23 D 43 C4 B 24 C 44 B5 B 25 B 45 B6 C 26 C 46 B7 D 27 D 47 B8 A 28 A 48 A9 B 29 D 49 C

10 C 30 A 50 B11 B 31 B12 A 32 C13 A 33 C14 A 34 B15 A 35 D16 D 36 A17 D 37 A18 D 38 C19 B 39 A20 C 40 C

2

Kertas 2-Bahagian A

No. Rubric Mark

1 (a)

(b)

(c)

(d)

(e)

P: liquidS: solid

1. Particles of Q held together by weak intermolecular forces2. A small amount of heat energy is required to overcome

Diagram1. label2. functional apparatus

1. label of axis2. shape of graph

11

1

11

11

11…9

2 (a)(i) (ii)

(b)

(c)

(d)

(e)(i)

2.8.3F+3

A,D,C,B,G,F,E

Atom A has a stable/duplet electron arrangement/2 valance electron

1. Size of atom D is smaller than G2. Strength of the nucleus of atom D to attract electron increase

Ionic

11

1

1

11

1

3

Time ( min)

Temperature / oC

(e)(ii)

(e) (iii)

1. Number of shells and electrons2. Charge

- has high melting point and boiling point- conduct electricity in molten state or aqueous solution- soluble in water- insoluble in organic solvent

(Any one)

11

1...10

3 (a)

(b) (i) (ii) (iii) (iv)

(c) (i) (ii) (iii) (iv)

(d)

H+ , Cu+2

Copper electode becomes thicker//brown solid is depositedCu+2 + 2e CuCopperOxygen

(from zinc plate to copper plate)Oxidation0 to +2Increases

Zn + Cu+2 Cu + Zn+2

1

1111

1111

1...10

4 (a)(b) (i) (ii)

(c) (i)

(ii)

Boron oxideTin1. The presence of tin atoms of different size from the atoms of

copper distrupts the orderly arrangements of copper atoms2. This prevents the layers of atoms from sliding over one another

easily

H Cl | | C == C | | H H

Does not corrode

111

1

1

1

4

-

D

-

DE

xxx

xxx

2+

x xxx

xx

(d)

(e) (i)

(ii)

Reinforced concrete

2NH3 + H2SO4 (NH4)2SO4//2NH4OH + H2SO4 (NH4)2SO4 + 2H2O

% N in CO(NH2)2 =

% N in (NH4)2SO4 =

Urea has higher percentage of nitrogen so it is more suitable for the growth of plants

1

1

1

1

1…11

5 (a)

(b)(i)

(ii)

(c)(i)

(ii)

(d)(i)

(ii)

J: alkeneK: alcohol

Butan-2-ol

Hydration/addition of steam

Orange to green

C3H7COOH

C4H8 + 6O2 4CO2 + 4H2O

No of mole C4H8 =

=

= 0.11 mole of C4H8 4 mole CO2

0.1 mole of C4H8 0.4 mole CO2

Volume of CO2 = 0.4(24) = 9.6 dm3 / 9600 cm3

11

1

1

1

1

1

1

1

1…10

6 (a)

(b)(i)

Reduce heat released to the surrounding

Heat change = 200 x 4.2 x 13 = 10920 J

1

1

5

(b)(ii)

(c)

(d)

(e)(i)

(ii)

Mole of H+/OH-/water = 100 x 2.0 // 0.2 mol 1000Heat of displacement = - 10920 J // -54.6 kJmol-1

0.2 mol

1. Label the energy axis & correct energy level of the reactants and product

2. Correct chemical equation// ionic equation Heat released/ produced when 1 mol of water is formed

decreases

1. Ethanoic acid is a weak acid2. Some of the heat given out during the neutralization is used to

ionize/dissociate the ethanoic acid

1

1

1

1

1

1

11…10

6

H+ + OH-

H2O

Energy

Essay

No. Rubric Mark

7 (a) 1. pH value of ethanoic acid is higher than nitric acid2. ethanoic acid is a weak acid; nitric acid is a strong acid3. ethanoic acid ionises partially in water to produce lower

concentration of hydrogen ion 4. nitric acid ionises completely in water to produce higher

concentration of hydrogen ion

111

1…4

(b) 1. ammonia exist as molecule in chloroform2. there are no hydroxide ions present; the solution is not alkaline3. when ammonia ionises partially in water to produce hydroxide ion4. NH3 + H2O NH4

+ + OH-

5. the presence of OH- ions makes the solution alkali

11111…5

(c) 1. Pour [20-100]cm3 of zinc nitrate solution [0.1-1.0]mol dm-3 into a beaker

2. Add [20-100]cm3 of sodium carbonate solution [0.1-1.0]mol dm-3 3. Stir and filter the mixture4. Pour [20-100]cm3 dilute/[0.1-1.0]mol dm-3 sulphuric acid into a

beaker5. Add the residue/precipitate into the acid until in excess6. Stir and filter the mixture7. Heat the filterate until saturated/1/3 of original volume8. Cool the saturated solution9. Filter and dry the crystal10. Zn(NO3)2 + Na2CO3 ZnCO3 + 2NaNO3

11. ZnCO3 + H2SO4 ZnSO4 + H2O + CO2

1

111

1111111...11

20

7

No. Rubric Mark

8 (a) Formula that shows the simplest ratio of the number of atoms for each element in the compound. 1…1

(b) Empirical formula : CHRMM of (CH)n = 78 [ 12 + 1]n = 78 13 n = 78 n = 6

Molecular formula : C6H6

1

11

11…5

(c) Procedure:1. Clean magnesium ribbon with sand paper2. Weigh crucible and its lid3. Put magnesium ribbon into the crucible and weigh the crucible

with its lid 4. Heat strongly the crucible without its lid5. Cover the crucible when the magnesium starts to burn and

lift/raise the lid a little at intervals6. Remove the lid when the magnesium burnt completely7. Heat strongly the crucible for a few minutes8. Cool and weigh the crucible with its lid and the content9. Repeat the processes of heating, cooling and weighing until a

constant mass is obtained10. Record all the mass

Results:

Mass/gCrucible + lid xCrucible + lid + magnesium yCrucible + lid + magnesium oxide z

111

11

1111

1

1

Element C HMass (%) 92.3 7.7Number of

moles = 7.7 = 7.7

Ratio of moles 1 1

8

Calculations:

Empirical formula: MgaOb / MgO

1

1

1...14

20

No. Rubric Mark

9 (a) 1. Oxidation - increase in oxidation number2. Reduction – decrease in oxidation number

11…2

(b)(i) 1. Fe+2 Fe+3 + e2. Br2 + 2e 2Br –

3. Iron(II) ions lose electrons to become iron(III) ions. Iron(II) ions are oxidised

4. Bromine molecules gain electrons to form bromide ions. Bromine molecules are reduced

(a: any suitable reducing agent)

1. Fe+3 + e Fe+2 2. Zn Zn+2 + 2e3. Iron(III) ions gain electrons to become iron(II) ions. Iron(III)

ions are reduced4. Zinc atoms lose electrons to form zinc ions. Zinc atoms are

oxidised(a: any suitable reducing agent)

111

1

111

1…8

Element Mg OMass (g) y-x z-y

Number of moles

Simplest ratio of moles a b

9

(c) Diagram: 1. label2. functional apparatus

Procedure: 1. Pour dilute sulphuric acid into a U-tube2. Using a dropper, add iron(II) sulphate solution at one side 3. and acidified potassium manganate(VII) solution at another side4. Place carbon electrode in each side of the U-tube5. Connect the electrodes to a galvanometer by using connecting

wires//Complete the external circuit6. Record any change that can be observed after a few minutes

Observations: The green colour of iron(II) solution turns to brownThe purple colour of acidified potassium manganate(VII) solution is decolourised/change to colourless

(a: any suitable cell)

11

11111

1

11…10

20

No. Rubric Mark

10 (a) (i)

Catalyst is a substance that changes the rate of a chemical reaction. 1

(a) (ii) - does not change the amount of product formed.- unchanged chemically at the end of reaction.- the amount of catalyst is the same before and after the reaction.- it is specific for a reaction.- only small amount is needed to catalyze a reaction.- less effective when there are impurerities.- most of the catalyst are transition metals or their compound.(Any two)

11…2

(a) (iii) - Haber process: iron filling- Contact process: vanadium(V) oxide- Ostwald process: platinum(Any one)

1…1

10

(b) 1 Size of reactant - size of reactant decrease, total surface area exsposed for collision between the particles reactants increase - frequency of collision between particles increase - frequency of affective collision increase rate of reaction increase

2 Concentration of reactant - concentration of a solution increase, number of particles per unit volume increase - frequency of collision between particles increase - frequency of affective collision increase rate of reaction increase

3 Temperature of reaction - temperature of reactants increase, kinetic energy of particles reactants increase - frequency of collision between particles increase - frequency of affective collision increase rate of reaction increase(Any two)

11

11…4

11

11…4

11

11…4

(c) 1 Cooking of solid food- solid food cut into small piece- total surface area exsposed to heat increase- food cook faster

2 Cooking of food in a pressure cooker- high pressure raises the boiling point of water.- cooking is carried out at a temperature higher than 100 o C.- food cook faster.

3 Storing of food in a refrigerator- temperature in refrigerator is lower- microorganisms inactive- slow down rate of food decaying

(Any two)(a: any suitable answer than above)

1111…4

1111…4

1111…4

20

11

PAPER 3

1 ( a )

Score Rubric3 [ Able to state all 11 readings correctly ]

2 decimal places Unit cm3

Suggested answer 49.60, 40.10, 31.50, 24.10, 19.50, 15.10, 11.50, 9.60, 8.10, 8.10. 8.10

2 [ Able to state any 8 readings correctly ]1 [ Able to state any 4 readings correctly ]0 No response or wrong response

1 (b)

Sco

re

Rubric

3 [Able to design a table and record the time, buret reading and volume of gas liberated] 1. Time /minute2. Buret reading /cm3

3. Volume of gas liberated

Suggested answer:

Time /min

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Buret reading /cm3

49.60 40.10 31.50 24.10 19.50 15.10 11.50 9.60 8.10 8.10 8.10

Volume of gas / cm3

0.00 9.50 18.10 25.50 30.10 34.50 38.10 40.00 41.50 41.50 41.50

2 [Able to design a table and record two of the 3 items (time, buret reading and volume of gas liberated] // [Able to design table without unit]

1 [Able to give idea on table ] Suggest answer: 2 rows x 11 columns

1 (c)

12

Score Rubric3 [ Able to draw 2 graphs of volume of carbon dioxide gas liberated against time

for both experiments on the same axes with all the 4 items below correctly ] (i) suitable scale used (ii) axes labelled correctly(iii) all points plotted correctly(iv) smooth curve of graphs

2 [Able to draw the graphs of volume of carbon dioxide gas liberated against time for both experiments on the same axes with at least 3 items correctly] //[Able to draw one of the graphs volume of carbon dioxide gas liberated against time with at least 4 items abovebelow correctly]

1 [ Able to manipulate two items correctly ]0 No response or wrong response

1 ( d )

Score Rubric3 [Able to deduce the relationship between the size of marble chips and the rate of

reaction correctly].

Suggested answer:Small pieces of marble chips have a large total surface area than that a large pieces of marble chips of the same mass, course the time taken for reaction more faster / rate of reaction more higher

2 [Able to give incomplete relationship]Suggested answer:Small pieces of marble chips have a large total surface area time taken for reaction more faster / rate of reaction more higher

1 [Able to give an idea ]Suggested answer:Small pieces of marble chips have a large total surface area // time taken for reaction more faster when size of reactant smaller // rate of reaction depend on the size of reactant

0 No response or wrong response

1 (e)

13

Score Rubric3 [ Able to state three variables and the way to control them correctly ]

Example :Manipulated variable :Total suface area of marble Replace large marble chips with

small small marble chipsResponding variable :Rate of reaction // time Measure the volume of gas collected

at half-minute intervalFixed variable :Mass of marble, volume of hydrochloric acid, temperature

Use the same mass/5.0 g marble, same volume/50 cm3 and concentration/ 0.1 mol dm-3

hydrochloric acid, same tepperature in each of the experiment

2 [ Able to state any pair of variable and action correctly ]

1 [ Able to state any variable and any action correctly // any two variables correctly // any two action correctly]

0 No response or wrong response

1 (f)

Score Rubric3 [Able to state relationship small pieces of meat and time to cook correctly]

Suggested answer Smaller pieces of meat has bigger total surface area The larger surface area provides a larger area for absorbtion heat Increased obsorption of heat shorten cooking time// The rate of reaction

increases2 [Able to give incomplete relationship ]

Suggested answer[state the any two items above]

1 [Able to give an idea // state any one items above]

0 No response or wrong response

2 (a)

14

Score Rubric3 [Able to give the hypothesis accurately]

Suggested answer :The further the metal is from copper in the electrochemical series, the greater is their potential different/ voltage reading. //The further apart the metal is in the electrochemical series, the greater the potential different/ voltage reading.

2 [Able to give the hypothesis almost accurately]

Suggested answer :The further the metal is from copper in the reactivities series, the greater is their potential different/ voltage reading. //The further apart the metal is in the reactivities series, the greater the potential different/ voltage reading.

1 [Able to state an idea of hypothesis]

Suggested answer :The position of metal influence the different potential/ voltage reading.Type of metal influence the different potential/ voltage reading.

0 No response or wrong response

2 (b)Score Rubric

3 [Able to arrange all the 5 metals according to descending order of electropositivity correctly]

Suggested answer:Magnesium, Aluminium, Zinc, Iron, Copper[a: formula]

2 [Able to arrange all the 4 metals but according to increasing order of electropositivity correctly]

Example:Mg, Al, Fe, Cu, Zn // Al, Zn, Fe, Cu, Mg // Al, Zn, Mg, Fe, Cu

1 [Able to arrange all the 5 metals but according to ascending order of electropositivity correctly]Example ;Cu, Fe, Zn, Al, Mg

0 No response or wrong response2 (c)

15

Score Rubric3 [Able to state inference correctly].

Suggested answer Electrical energy is not produced No movement of electron because the same type of metal are used as

electrodes in a voltaic cell

2 [Able to state inference not completely].

Suggested answerElectrical energy is not produced // no movement of electron because the same type of metal are used as electrodes in a voltaic cell

1 [Able to state an idea]

ExampleNo electric/electron/potential difference

0 No response or wrong response

2 (d)

Score Rubric3 [Able to state three observations correctly]

Suggested answer:1 Zinc dissolved // becomes thinner2 Copper becomes thicker // brown solid deposited3 Blue solution becomes light blue /fading in colour

2 [Able to state two observation correctly]

1 [Able to state one observation/idea about observation of the cell]

0 No response given or wrong response

16

2 (e)

Score Rubric3 [Able to predict correctly]

Answer: 1.0 V

2 [Able to predict almost correctly]

Example: 1.0

1 [Able to state an idea to arrange the metals]

Example:Reading is higher than 0.5 / lower than 1.5

0 No response or wrong response

Essay

3 (a) - Statement of the problem

Score Rubric

3

[ Able to give the statement of problem correctly ]

Example :How the effect on rusting when iron is in contact with another metals?

2

[ Able to give the statement of problem incorrectly ]

Example :To investigate the effect of other metals on the rusting of iron

1

[ Able to state an idea the statement of problem]

Example :To study the rusting of iron

0 [ No response or wrong response]

3 (b) - variables

17

Score Rubric

3

[ Able to state All variables correctly ]

Suggested answer : Manipulated variable : Different types of metals// Different metalsResponding variable : Rate of rusting // Rusting of ironConstant variable : Iron nails/temperature

2 [ Able to state any two variables correctly ]

1 [ Able to state any one variables correctly ]

0 [ No response or wrong response]

3 (c) - hypothesis

Score Rubric3 [Able to give the hypothesis accurately]

Suggested answer :When a more electropositive metal is in contact with iron, the metal inhabits rusting // When a less electropositive metal is in contact with iron, the metal speed up rusting // Iron rusts faster when in contact with metal less electropositive

2 [Able to give the hypothesis almost accurately]

Suggested answer :When a more reactive metal is in contact with iron, the metal inhabits rusting

1 [Able to state an idea of hypothesis]

Suggested answer :When a less electropositive metal is in contact with iron, the metal inhabits rusting

0 No response or wrong response

3 (d) - Apparatus and materials

18

Score Rubric

3

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

Suggested answer :Apparatus : Five test tubes, test tube rack Materials : sand paper, five iron nails, magnesium strip, zinc strip, tin strip, copper strip, hot agar-agar/jelly solution mixed with potassium hexacyanoferrate(III) solution and phenolphthalein indicator

2

[ Able to give the list of the apparatus and substances correctly and but not completely]

Example :List of apparatus and materialsTest tube, iron nail, magnesium,zinc, tin,copper,water, potassium hexacyanoferrate(III) / phenolphthalein indicator

1

[ Able to give an idea about the list of the apparatus and materials correctly]

Example :Any one apparatus and two materials

0 [No response or wrong response]

3 (e) - Procedure of the experiment

Score Rubric

3

[ Able to state all procedures correctly ]

Suggested answer :1. Clean all the metal strips with sand paper2. Coil the metal strip around the iron nails and then put in the each test tube 3. Pour the same volume of hot agar-agar/jelly solution has been mixed with potassium hexacyanoferrate(III) and phenolphthalein indicator 4. Leave the test tubes aside for one day5. Compare the intensity of the blue and pink colour in each test tube and recorded

2[ Able to state 3 steps of procedures correctly ]Example : Steps 2,3,5

1[ Able to state 2 steps of procedures correctly ]Steps 2,3

0 [No response or wrong response]

3 (f) - Tabulation of data

19

Score Rubric

3

[ Able to exhibit the tabulation of data correctly ]

Tabulation of data has 6 columns and 3 rows

Example :Test tube A B C D E

Intensity of blue colourIntensity of pink colour

2

[ Able to exhibit the tabulation of data less accurately ]

Tabulation of data has 6 columns and 2 rows

Example :Test tube A B C D E

Observation

1

[ Able to state an idea about the tabulation of data ]Tabulation of data has 2 columns and 2 rows

0[No response or wrong response]

Total 3 × 6 = 18Max 17

Nota utk pemeriksa*

Markah Kertas 1 + Markah Kertas 2 + Markah Kertas 3 = Markah keseluruhan 2

50 + 100 + 50 = 100% 2

END OF MARKING SCHEME

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