spm trial 2012 chemistry qa selangor

7/27/2019 Spm Trial 2012 Chemistry Qa Selangor

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SULIT Google Search : mr sai mun 4541@ Kertas PPPA(2) Kimia SPM

4541@ Hakcipta Jabatan Pelajaran Negeri Selangor SULIT

PPPA SPM 2012MARKING SCHEME OF PAPER 1 (4541/1)

PPPA SPM 2012

1. C 26. B2. B 27. A3. B 28. A4. D 29. A5. C 30. C6. C 31. A7. C 32. D8. C 33. B9. A 34. C10. C 35. A11. D 36. B12. C 37. A13. C 38. C14. D 39. D15. B 40. B16. C 41. D17. B 42. C18. B 43. A19. A 44. B20. C 45. A21. C 46. C22. D 47. B23. D 48. C24. B 49. C25. D 50. B

END OF MARKING SCHEME

SKEMA JAWAPAN TAMAT

http://www.chngtuition.blogspot.com


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Google Search : mr sai mun

1 Google Search : mr sai mun mrsaimun.blogspot.com

SKEMA JAWAPAN KERTAS KIMIA 3 (4541/3)PPPA SPM 2012

MARKING SCHEME OF PAPER 3(4541/3)PPPA SPM 2012

Question Description Marks

1 (a) (i) [Able to give a definition correctly]The temperature at which solid turns to liquid 1

......1

(ii) [Able to state the boiling point correctly]136

0C 1 ......2

(iii) [Able to explain the reasons correctly]

Heat energy is absorbed and

used to overcome the force of attraction between particles

// Heat is absorbed to overcome the intermolecular force between moleculer: ion/atom

1

1 ......2

(b) (i) [Able to state the process correctly ]

Diffusion

1

.1

(ii) [Able to explain the observations correctly

- Potassium manganate(VII)is made up of tiny particles- The spaces between particles in gel are smaller than in water//vice versa

- Potassium manganate (VII) particles diffuse slower in gel // vice versa

1

1

1 .3

9

Question Description Mark

2 (a) Form complex ion/ Act as a catalyst/Form coloured ion or compound/exhibit

different oxidation numbers in compounds1

....1

(b) The outermost shell of atom R has already achieved stable octet electron

arrangement/ Atom R has 8 valence electron1

.....1

(c) T2 + H2O HT + HOT 1 .....1

(d) (i) T 1 .....1

(ii) - Atomic size of atom T is smaller than atom S

- Strength of the nucleus/nuclei attraction to attract electron of atom T is

stronger than atom S

1

1 .....2

(e) (i) Covalent bond 1 .....1

(ii)

- Diagram showing correct sharing of electrons between four atoms S and

one atom Q with label/nucleus- Correct number of electrons in each shell

1

1 .....2

Total 9

Q

S

S

S

S



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3 (a) (i) Colourless solution turns blue // Some of black solid dissolves1

.....1

(ii) Copper(II) sulphate

1 .....1

(b) To ensure all acid react completely 1 .....1

(c) (i) Double decomposition// precipitation 1 .....1

(ii) Pb2+ + SO42- PbSO4

Correct formulae of reactants and product

Balanced equation

1

1 ....2

(iii) Lead (II) sulphate 1 ....1

(iv)

= = 0.01 mol 1

(v) From eq: 1 mol SO42-

produce 1 mol PbSO4//

0.01 mol SO42-

produce 0 .01 mol PbSO4= 0.01 X 303

= 3.03 g

1

1.....2

10


(i) Contact Process 1

......1

(a)

(ii) Sulphur // oxygen// water 1

........1(i) Ammonium sulphate

(NH4)2SO4

1

1 ........2

(b)

(ii) Percentage of nitrogen = 14 x 2 x 100%

132

= 21.21 %

1

1 .....2

(i) Analgesic 1 .....1

(ii) Relieves aches and pain / reduces inflammation / reduces fever 1 .......1

(iii) Penicillin / chloramphenicol / erythromycin 1 ......1

4

(c)

(iv) To reduce depression / tension / worry // to calm a person 1 .....1

Total 10

0.5 x 20

1000



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5 (a) (i) [able to state the Homologous series correctly]

compound P - alkene

compound Q - alkane1

........1

(ii) [able to state the general formula of compound R correctly]

CnH2n+1OH1

........1

(iii) [able to state the process correctly]

Dehydration process1 ........1

(iv)

1.(functional set up of apparatus, gas is collected by water

displacement method)2. correct labels

1

1 ........2

(b) (i) Gas X carbon dioxide1 ........1

(ii) [able to write a balance chemical equation]

C2H4 + 3O2 2CO2 + 2H2O /C2H6 + 7/2O2 2CO2 + 3H2O

1

........1

(c) [able to state observation]

Effervesence occurs1

(d) [able to draw the structural formula of product formed and name correctly]

Ethyl propanoate

1

1 .......2

Total 11

H H

H

H

CC C C

H

H H

H

O

O

H

H

C

Gas P

water

Glass woolSoaked in

R

Porcelain chips

Heat



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Question Description Mark

6 (a) Heat of precipitation is the heat change when one mole of a precipitate isformed from its ion in aqueous solution

1.....1

(b) (i) The heat released

= mc=(50 + 50) x 4.2 x 3.5

=1470 J 1 .....1

(ii) Number of moles of Ag+= (50 x 0.5) = 0.025 mol

1000Number of moles of Cl

-

= (50 x 0.5) = 0.025 mol

1000

1

1

......2

(iii) 0.025 mole of Ag+

reacts with 0.025 mole of Cl-to form 0.025 mole of

AgCl

Number of moles of AgCl = 0.025 mol

1

.......1

(iv)= x 1470 J

=58 800 J

Heat of precipitation of AgCl = -58.8 kJ mol-1

1

1 ......2

(c)

1. Label axes

2. Energy levels of reactants and products correct with formula ofreactants and products

3. Heat of precipitation written

1

1

1 ......3

(d) Ag+

+ Cl-AgCl 1

......1

Total 10

Ag+

+ Cl-

H = -58.8kJmol-1

AgCl

Energy



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(i) J, K, Cu, L 1 17 (a)

(ii) [Able to state the negative terminal with correct explanation ]1. Negative terminal is K

2. Because K is more electropositive than L/above L in

Electrochemical Series[ Able to predict voltage value of cell K/L]

3. Voltage value is 1.80V

1

1

1 3

(i)[Able to state the factors that determine the products formed

at electrode X]

The type of electrode 1 1

(ii) [Able to explain the reactions at each electrodes]

Electrode Anode / Electrode X Cathode/ Electrode Y

Ion attracted SO42-

, OH-

Cu2+

, H+

Half equation Cu Cu2+

+ 2e Cu2+

+ 2e Cu

Observation Copper electrodebecome thinner

Brown solid deposited

1+ 1

1+ 1

1+ 1 6

(b)

(iii) [Able to state the product at Electrode X with correct explanation]1. Oxygen gas is formed.

2. SO42-

and OH-ions attracted to Electrode X.

3. OH-ion is selected for discharge because it is lower in position than

SO42-

ion in Electrochemical series.4. Half equation : 4OH

- O2 + 2H2O + 4e

- Correct formula- 1

- Balance equation - 1

1

1

1

1+1 5

(i) [Able to arrange the three metals according to their increasing

electropositivity]The order of the three metals in ascending order of electropositivity

R , P , Q

electropositivity increases

1

1

(c)

(ii)[Able to state the strongest reducing agent with correct explanation]

1. Q is the strongest reducing agent.

2. The easier the metal atom to release electron, the higher the tendency

of metal to act as stronger reducing agent.3. Q is the most electropositive metal, so it has highest tendency to

release electron.Total

1

1

13

20



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8 (a) 1. Total surface area of smaller pieces wood is larger/bigger/ greater

than the bigger pieces of wood

2. Larger surface area of smaller pieces wood exposed to air for

burning

11 .....2

(b) (i) Substance that can alter (change) the rate of reaction but the substanceitself does not change chemically

1......1

(ii) 2H2O2 2H2O + O2

1. Correct formulae of reactants and product

2. Balanced equation1

1

.......2

(iii)

1. Axis with correct label

2. Curve without catalyst, Ea, Curve with catalyst , Ea

3. Position energy level of reactant

4. Label H

5. Heat absorb during breaking of bond in the ractaant is lower than

heat release during formation of bond in the product.

6. Energy content of reactant is higher than energy content of product7. The reaction is exothermic

8. In the presence of catalyst/ manganese(IV) oxide provide an

alternative path/ lower activation energy

9. Frequency of effective collision between hydrogen peroxidemolecules increases

any 7

1

11

11

1

1

.....7

c (i) Zn + 2HCl ZnCl2 + H2

No. of mol HCl = 50 X 0.5 // 0.0251000

Based on the chemical equation;2 mol HCl : 1 mol H2

0.025 mol HCl : 0.0125 mol H2

Volume of H2 = 0.0125 x 24 // 0.3dm3

1

1

1

1 ......4

Energy

2H2O2

Ea

2 H2O + O2

Ea



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(ii) 1. Pour /measure 12.5 cm3

of 1 mol dm-3

hydrochloric acid .

2. Add excess zinc powder

3. At the same temperature

OR

1. Pour/measure 25 cm3

of 0.5 mol dm-3

hydrochloric acid

2. Add excess zinc powder

3. At the higher temperature

1

1

1

1

1

1 ....3

(iii)Because the number of mol of hydrochloric acid used is half

1....1

20


9 (a) (i) Acid P : Nitric acid/hydrochloric acid (any strong acid) r : sulphuric acid

Acid Q : ethanoic acid (any weak acid)

Sample answer:2HCl + CaCO3 CaCl2 + H2O + CO2 //

2HNO3 + CaCO3 Ca(NO3)2 + H2O + CO2

1

1

1.....3

(ii)Acid P Acid Q

1. Acid P is a strong

acid/Ionises completely inwater/

HCl H+

+ Cl-

2. Concentration of H+

is higher3. The rate of reaction higher

1.Acid Q is a weak acid/Ionises

partially in water/CH3COOH CH3COO

-+ H

+

2.Concentration of H+

is lower

3.The rate of reaction lower

3 + 3

.....6

(b) (i) Zinc oxide 1 .....1

(ii)

1. Functional diagram

2. Label

1

1 .....2

Zinc carbonate

powder



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(c) 1. Add excess nitric acid/hydrochloric/sulphuric acid to zinc carbonate

2. Pass gas through lime water3. Lime water turns cloudy/ chalky/ milky

4. shows the presence of CO32-

ion5. Pour solution produced into 2 test tubes

Test tube 16. Add aqueous sodium hydroxide until excess, shake.

7. If white precipitate formed and dissolves in excess NaOH, Zn

2+

or Al

3+

or Pb2+

ions present

Test tube 2

8. Add aqueous ammonia, NH3 until in excess shake.9. If white precipitate formed and dissolves in excess NH3, Zn

2+ions

present

1

11

11

1

1

11

Max

8 ...8

20


10 (a) (i) Magnesium, Aluminium, Y, Copper 1

(ii) Iron/Tin/Lead 1

(iii) [Able to write a balanced chemicla equation]4 Al + 3 O2 2 Al2O3

1. Correct formula of reactants and product

2. Balanced equation

3. Oxidation number of aluminium increases from 0 to +3.

1

1

1 3

(iv) [Able to draw a labelled diagram]

1. Able to name potassium manganate(VII) or potassium chlorate(V)

2. Diagram complete and functional

3. Labels correct

1

1

1

(b) [Able to write the procedure]

1. A crucible and its lid is weighed and its weight is recorded.2. A 10 cm length of magnesium ribbon is cleaned with sand paper and

coiled loosely.The magnesium coil is placed in the crucible.3. The crucible with its lid and content are weighed again and the weight is

recorded.4. The crucible is heated strongly without its lid.

5. When the magnesium starts to burn, the crucible is covered with its lid.

6. Using a pair of tongs, the lid is lifted at intervals.

7. When the burning is completed, the lid is removed andthe crucible is heated strongly for 2 minutes.

8. The crucible is allowed to cool to room temperature.9. The crucible and its lid and content are weighed again and its weight is

recorded.

1

1

11

1

1

11

1

Potassiummanganate(VII)/

chlorate V

Glass wool Metal

HeatHeat



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10.The processes of heating, cooling and weighing are repeated until a

constant mass is obtained.

[Able to show tabulation of data]Mass (g)

Crucible + lid a

Crucible + lid + magnesium b

Crucible + lid + magnesium oxide c

[Able to show calculation ]Element Magnesium Oxygen

Mass(g) b-a c-b

Number of molesof atoms

b-a/24 c-b/16

Simplest ratio ofmoles

x y

Empirical formula = MgxOy

1

Max 8

1

2

1 12

20

.......1

.......1

.......1

.......1



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SKEMA JAWAPAN KERTAS KIMIA 3 (4541/3)PPPA SPM 2012

MARKING SCHEME OF PAPER 3(4541/3)PPPA SPM 2012

Question Rubric Score

[Able to record all readings accurately to one decimal point with unit]

Sample answer:

Experiment Copper Bronze

I 3.2 cm 2.0 cm

II 2.9 cm 2.3 cm

III 3.2 cm 2.0 cm

# Accept unit mm : 1 cm = 10 mm

3

[Able to record all readings accurately with correct decimal point or unit] readings to one decimal point without unit readings to two decimal point with unit

Sample answer:


I 3.2 2.0

II 2.9 2.3

III 3.2 2.0

Or


I 3.20 cm 2.00 cm

II 2.90 cm 2.30 cm

III 3.20 cm 2.00 cm

2

[Able to record three to five readings correctly]1

1(a) (i)

[No response given or wrong response] 0



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[Able to show calculations of both average diameter correctly]Sample answer:

Copper : 3.2 + 2.9 + 3.2 = 3.1 cm3

Bronze : 2.0 + 2.3 + 2.0 = 2.1 cm3

# Accept calculation in mm : 1 cm = 10 mm

3

[Able to show calculation of any one average diameter correctly] 2

[Able to give idea of calculation of average diameter]1

1 (a) (ii)

[No response given or wrong response]0


[Able to construct a table to record the diameters of the dents and average

diameters for copper and bronze with the following aspects]

1. Correct titles

2. Readings and unit

Sample answer:

Diameter of dents (cm)Material

1 2 3

Average

Diameter (cm)

Copper 3.2 2.9 3.2 3.1

Bronze 2.0 2.3 2.0 2.1

3

[Able to construct a less accurate table to record the diameters of the dentsand average diameters for copper and bronze with the following aspects]

1. Title2. Readings

Sample answer:

Diameter of dents

1 2 3

Average

Diameter

Copper 3.20 2.90 3.20 3.10

Bronze 2.00 2.30 2.00 2.10

2

[Able to construct a table with at least one title/ reading]Sample answer:

Diameter of dents

1 2 3

Copper

Bronze

1

1(a) (iii)

[No response given or wrong response] 0



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[Able to state the observation correctly ]Sample answer:The diameter of dents made on bronze/ copper is smaller/bigger than

copper/bronze.

3

[Able to state the observation less correctly]Sample answer:

The diameter of dents made o bronze/ copper is smaller/bigger.

2

[Able to state an idea of the observation]

Sample answer:The diameter of dent for bronze is small/ /The diameter of dent for copper isbig.

1

1( b)

[ No response or wrong response]0

Question Rubric Score[Able to state the inference correctly]Sample answer:Bronze/ copper is harder/softer than copper/bronze.

3

[Able to state the inference less correctly]Sample answer:Bronze/ copper is harder/softer.

2

[Able to state an idea of the inference]Sample answer:

Bronze/ copper is hard/soft.1

1(c)

[No response or wrong response] 0


[Able to state three variables correctly]

Sample answer:Manipulated variable: Different types of materials/block//copper and

bronze

Responding variable: Size / diameter of dent// hardness of the blockConstant variable: Mass of the weight// Height from which weight is

released// Size of steel ball bearing

3

[Able to state any two variables correctly ]2

[Able to state any one variable correctly]1

1(d)

[No response or wrong response]0



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

responding variable with direction correctly]

Sample answer:Bronze is harder than copper // Copper is softer r than bronze

//Bronze has smaller size / diameter of dent than copper// alloy is

harder than its pure metal

3

Able to state the relationship between the manipulated variable and

responding variable

Sample answer:When the size / diameter of dent is smaller, the material is harder 2

[Able to state the idea of hypothesis]

Sample answer:

Different materials have different diameter/size of the dent

1

1(e)



[Able to state the operational definition for hardness of material block

correctly ]

Sample answer:

When weight is dropped on the surface of the block/when force is

applied. the material that has a smaller dent is the alloyr

3

[Able to state the operational definition less accurately]Sample answer:The material that has smaller size / diameter of dent is the alloy.

2

[Able to state an idea of the operational definition]Sample answer:

Bronze is alloy.

1

1(f)

[ No response or wrong response] 0


[Able to state the relationship accurately]Sample answer:The smaller the diameter of the dent, the harder the material/block. //The bigger the diameter of the dent, the softer the material/block.

3

[Able to state the relationship less accurately]Sample answer:The smaller the diameter of the dent, the stronger the material/block.

2

1(g)

[Able to state an idea of the relationship]Sample answer: 1



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Different material/block produce different diameter of dent[No response or wrong response]

0


[Able to give all three explanations correctly]

Sample answers:1. Atoms in copper are in orderly arrangement.2. Atoms in bronze are not in orderly arrangement./ Arrangement of atoms inbronze is disrupted.3. Layers of atoms in bronze difficult to slide on each other when force is

applied

3

[Able to give any two explanations correctly]2

[Able to give any one explanations correctly]1

1(h)


Question Rubric Score[Able to classify all the six materials correctly]

Sample answer:

Pure metal Alloy

Aluminium Brass

Tin Pewter

Iron Stainless steel

3

[Able to classify any four materials correctly] 2

[Able to classify any two materials correctly]

if reverse score 1

Sample answer:

Pure metal Alloy

Brass Copper

Pewter Tin

Stainless steel Iron

1

1(i)


Question Rubric Score2(a)

[Able to state the problem statement correctly]Sample answer:

Do salt A and salt B dissolve in water ?// Are salt A and salt Bsoluble/insoluble salt?

3

[Able to state the problem statement less accurately]Sample answer:Does salt A/B dissolve in water? //To identify the solubility of salt A and

2



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salt B

[Able to give an idea of the problem statement]Sample answer:Can salt A and salt B mix with water?

1



2(b) [Able to state the three variables correctly]Sample answer:Manipulated variableSalt A and Salt BResponding variableSolubility of saltConstant variableQuantity Water / quantity of salt / temperature of water

3

[Able to state any two variables correctly]2

[Able to state any one variable correctly]1


Question Rubric Score2(c)

[Able to state the relationship correctly between the manipulated variable and

the responding variable with direction]Sample answer:

If salt A and salt B dissolve in water , salt A and B are soluble salt

soluble/insoluble salt //

3

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

responding variable with direction]

Sample answer:

Salt A/Salt B is soluble/insoluble salt

2

[Able to state the idea of hypothesis]Sample answer:Salt A/Salt B can mix with water

1


Question Rubric Score2(d) [Able to give complete list of substances and apparatus]

Sample answer:SubstancesSalt A, salt B and distilled waterApparatus

Beaker, glass rod, spatula

3

[Able to give a list of substances and apparatus but less complete]Sample answer:SubstancesSalt A, salt B and waterApparatusBeaker/test tube, glass rod

2

[Able to give at least two substance and at least one container]Sample answer :Substances

1



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Google Search : mr sai munSalt A, salt B and waterApparatusAny container[No response or wrong response] 0

Question Rubric Score2(e)

[Able to list all the steps correctly]

Sample answer:

1.Put one spatula of salt A in a beaker .2.Add distilled water until half full .3.Stir the mixture using glass rod.4.The solubility of salt A is recorded/record the observation.5. Repeat step 1 to 4 by replacing the salt A with salt B

3

[Able to list down steps 1, 2, 4 and 5] (no step 3) 2

[Able to list steps 1, 2 and 5] 1


Question Rubric Score2(f)

[Able to tabulate the data with the following aspects]

1. Correct titles2. List of substances

Sample answer:

Type of salt Observation / Solubility of saltSalt A

Salt B

2

[Able to construct table at least one title]

Sample answer:

Type of salt Observation / Solubility of salt

orType of salt

Salt A

Salt B

1

[No response or wrong response or empty table] 0

spm trial 2012 chemistry qa selangor

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