1. PENSKORAN // SCORING
SPM Chemistry Paper 3 2011
Question No. 1
Question No. 2
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CHEMISTRY PAPER 3 4541/3
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2. 2011
Question no. 1(a)(i)
Score 3: Able to state the OBSERVATION correctly
Sample answer
1. ‘X’ disappears from sight //
2. ‘X’ cannot be seen //
3. Yellow precipitate //
4. Yellow solid //
5. Solid cover ‘X’ //
6. Precipitate cover ‘X’
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3. 2011
Question no. 1(a)(ii)
Score 3: Able to state the INFERENCE correctly
Sample answer
1. Sulphur is formed //
2. Rate of reaction in Set I is higher //
3. Rate of reaction in Set IV is the lowest //
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4. 2011
Question no. 1(b)
Score : Able to state all three VARIABLES
Sample answer
Manipulated variable:
Concentration of sodium thiosulphate solution
Reject: concentrated
Responding variable:
Time taken ‘X’ to disappear // Rate of reaction
Constant variable:
Volume of sodium thiosulphate solution //
Volume and concentration of hydrochloric acid //
Volume/size of conical flask // temperature //
Hydrochloric acid // sodium thiosulphate
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5. 2011
Question no. 1(c)
Score 3: Able to state the relationship between
manipulated variable and the responding variable
and state the direction
Sample answer
The higher the concentration of sodium
thiosulphate solution, the higher the rate
of reaction //
The higher the concentration of sodium
thiosulphate solution, the shorter the time
taken for ‘X’ disappear
Note: MV + RV + direction
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6. 2011
Question no. 1(d)
Score 3: Able to give the OPERATIONAL DEFINITION
accurately
Sample answer
What have been done
1. The time taken for the yellow precipitate to form, until
‘X’ mark is disappear / not seen
What did you see
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7. 2011
Question no. 1(e)(i)
Score 3: Able to write all the time taken and calculate
the value 1/time to two decimal places
Sample answer
Set II III IV
Time (s) 25 33 50
1/time (s-1) 0.04 0.03 0.02
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8. 2011
Question no. 1(e)(ii)
Score 3: Able to PLOT A GRAPH correctly which
fulfills all the following criteria
1. Both axes are labell and with units
2. Uniform scale
3. All points are transferred correctly
4. Best fit straight line
5. The size of graph must be more than 30% of the graph
paper
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9. 2011
Question no. 1(f)(i)
Score 3: Able to PREDICT the relationship between
the concentration of sodium thiosulphate solution
and the rate of reaction correctly
Sample Answer
The higher the concentration of sodium
thiosulphate solution, the rate of
reaction increase
Score 1: The higher the concentration of sodium
thiosulphate solution, the rate of reaction
decrease
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10. 2011
Question no. 1(f)(ii)
Score 3: Able to fulfill the following criteria
Sample answer
1. Extend the line on the graph
2. Show on the graph the way to obtain the value
3. State the time with unit
PLOT YOUR
GRAPH NOW
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11. 2011
Question no. 1(f)(ii)
Score 3: Able to sketch the graph of volume of
hydrogen gas against time
Sample answer
Concentration of sodium
thiosulphate solution (mol dm3)
X-axis & Y-axis without unit : Score 2
0.02
Reverse axis, correct shape: Score 2
Reverse axis, wrong shape : Score 1
[15.0 ≤ X < 20]
X 1/time (s-1)
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12. 2011
Question no. 1(g)
Score 3: Able to EXPLAIN with comparison by
referring to the height/quantity of precipitate formed
in a certain time correctly
Sample answer
1. Smaller/less quantity of precipitate
needed to cover ‘X’
2. The precipitate formed higher/thicker
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13. 2011
Question no. 1(h)
Score 3: Able to CLASSIFY all ions correctly
Sample answer
Anions Cations
Cl- Na+
OH- H+
S2O3 2-
If state reversible: Score 1
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14. 2011
Question no. 2(a)
Score 2: Able to state the PROBLEM STATEMENT of the
experiment correctly
Sample answer
How to construct an ionic equation for the formation
of lead(II) iodide / PbI2
If state ‘Aim’: Score 1
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15. 2011
Question no. 2(b)
Score 3: Able to state three variables correctly
Sample answer
Manipulated variable:
Volume of potassium iodide solution
Responding variable:
Height of precipitate formed
Constant variable:
1. Volume of concentration of lead(II) nitrate solution //
2. Concentration of potassium iodide solution //
3. Size of test tube //
4. Temperature
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16. 2011
Question no. 2(c)
Score 3: Able to state the relationship between manipulated
variable and responding variable and the direction
correctly
Sample answer
MV
When the volume of potassium iodide solution
increases, the height of precipitate formed increases
the until maximum / no change / constant
RV
direction
Reverse RV and MV with direction : Score 2
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17. 2011
Question no. 2(d)
Score 3: Able to list complete substances and apparatus
Sample answer
Substances:
1. Lead(II) nitrate (0.1 – 0.2 mol dm -3 )
2. Potassium iodide (0.1 – 0.2 mol dm -3 )
Apparatus:
1. Ruler
2. Test tube
3. Test tube rack
4. Stopper / glass rod
5. Burette / pipette / syringe
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18. 2011
Question no. 2(e)
Score 3: Able to state all the step in the procedure correctly
Sample answer
Procedure: KEY WORD jangan lupa
1. Label test tubes and put in the rack
2. Pour (4 – 6 cm3 ) of lead(II) nitrate solution into the
test tube
3. Pour 1cm3 of potassium iodide solution into the first
test tube, 2cm3 of potassium iodide solution into
second test tube until the 8th test tube.
4. Shake the test tube // stir the test tube
5. Leave the test tube
6. Measure and record the height of precipitate
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19. 2011
Question no. 2(f)
Score 3: Able to tabulate the data with the following
aspects
1. Correct titles with units
2. Complete list of volume to two decimal points
Sample answer
Test tube 1 2 3 4 5 6 7 8
Volume of lead(II) nitrate
5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00
solution (mol dm-3 )
Volume of potassium iodide
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00
solution (mol dm-3 )
Height (cm3)
Value untuk ‘volume’ sudah dinyatakan dlm ‘procedure’
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20. THE END
Thank You
KAMAL ARIFFIN BIN SAAIM
SMK DATO’ BENTARA LUAR BATU PAHAT
e-mel : kamal_ariffin2006@yahoo.com
website: http://kemhawk.webs.com/
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