ujian pengesanan pertengahan tahun 2009_mark scheme chemistry 3
TRANSCRIPT
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7/31/2019 Ujian Pengesanan Pertengahan Tahun 2009_Mark Scheme Chemistry 3
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SULIT
4541/3
Chemistry
Paper 3
May
1 1/2 hours
JABATAN PELAJARAN MELAKA
____________________________________________________________
UJIAN PENGESANAN PERTENGAHAN TAHUN
SIJIL PELAJARAN MALAYSIA 2009
CHEMISTRY
Paper 3
One hour and thirthy minutes
MARKING SCHEME
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Question Rubric Score
1 (a) (i) Able to record all readings accurately to one decimal pointwith
unit
Sample answer:Set I: 55.0s Set II: 48.0s Set III: 42.0s
Set IV: 37.0s Set V: 33.0s
3
Able to record all readings correctlywithout unit / withoutdecimal point
Sample answer:
Set I: 55.0 / 55s Set II: 48.0 / 48s Set III: 42.0 / 42s
Set IV: 37.0 / 37s Set V: 33.0 / 33s
2
Able to recordthree readings correctly
Sample answer:
Set I: 55 Set II: 45.6 Set III: 42Set IV: 37 Set V: 30.6
1
No response or wrong response 0
1 (a) (ii) Able to construct a table that contain:
1 Correct titles2 Readings and units
Sample answer
Set Temperature / 0C Time taken / s
I 30.0 55.0
II 35.0 48.0
III 40.0 42.0
IV 45.0 37.0
V 50.0 33.0
Note : ecf for the time taken for Set I to Set V
3
Able to construct a less accurate table that contain:
1 Titles
2 Readings without unit 2
2
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Question Rubric Score
Sample answer
Temperature Time taken
Set I 30.0 55.0Set II 35.0 48.0
Set III 40.0 42.0
Set IV 45.0 37.0
Set V 50.0 33.0
Able to construct a table with at leasttwo title
Sample answer
Temperature Time taken30 55
35 48
40 42
45 37
50 33
1
No response or wrong response 0
1 (b) Able to give the relationship accurately and state the direction.
Sample answer:
The higher the temperature, the shorter the time taken formagnesium ribbon to completely dissolved.
3
Able to give the relationship correctly without state the direction
Sample answer:
Temperature affects time taken for magnesium ribbon to
completely dissolve.
2
Able to give an idea of the relationship
Sample answer:
Time for magnesium ribbon to dissolve become shorter
1
3
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Question Rubric Score
No response or wrong response 0
1 (c) Able to state all three variables correctly
Sample answer:Manipulated variable: Temperature
Responding variable: Time taken
Constant variable: Concentration & volume of
hydrochloric acid // length ofmagnesium ribbon
3
Able to state any two variables correctly 2
Able to state any one variables correctly 1
No response or wrong response 0
1 (d) Able to give accurate reading ( 37.0s < X < 42.0s) to onedecimal point with unit
Sample answer:38.0s // 39.0s // 40.0s // 41.0s
3
Able to give correct reading without decimal point / unit
Sample answer:
38s // 39.0 // 40s // 41.0
2
Able to give range of reading without decimal point / unit
Sample answer:
(37.0 < X < 42.0)
1
No response or wrong response 0
2 (a) Able to draw a graph of the height of precipitate against volume
of potassium chromate(VI) by showing the following information
i. The axes are labeled correctly with unit
ii. Uniform scale & size of the graph at least 50% of the
3
4
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Question Rubric Score
graph paper
iii. All points are transferred correctly
Able to draw a graph of the height of precipitate against volume
of potassium chromate(VI) by showing the following information
i. The axes are labeled correctly without unit
ii. All points are transferred correctly
2
Able to draw a graph of the height of precipitate against volume
of potassium chromate(VI) by showing the following information
i. The axes are labeled correctly without unit
ii. Curve / straight line on the graph
1
No response or wrong response 0
2 (b) Able to state the observation correctly
Sample answer:
The height of the precipitate increases from test tube 1 to test tube4 and become constant from test tube 5 to test tube 7.
3
Able to state the observation incompletely.
Sample answer:The height of the precipitate increases and then become constant
2
Able to state an idea of the observation
Sample answer:
The height of the precipitate increases.
1
No response or wrong response 0
2 (c) Able to state the inference correctly
Sample answer:
The reaction has been completed at test tube 5 because the heightof precipitate becomes constant from test tube 5 to test tube 7.
3
Able to state the inference incompletely.
Sample answer:The reaction has been completed when the height of precipitate
becomes constant.
2
5
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Question Rubric Score
Able to state an idea of inference.
Sample answer:
The reaction has been completed at test tube 5
1
No response or wrong response 0
2 (d) Able to state the relationship correctly between the manipulated
variable and the responding variable with direction.
Sample answer:
As the volume of potassium chromate(VI) increased, the height ofthe precipitate increase until it achieves a maximum height.
3
Able to state the relationship between the manipulated variableand the responding variable with direction.
Sample answer:When the volume of potassium chromate(VI) increased, the
height of the precipitate also increase.
2
Able to state the idea of hypothesis.
Sample answer:
The height of the precipitate increase.
1
No response or wrong response 0
2 (e) Able to state the correct operational definition for continuous
variation method correctly.
Sample answer:
The height of precipitate formed will increased and remainconstant when a fix volume of lead(II) nitrate solution is added
with potassium chromate(VI) solution.
3
Able to state the meaning of continuous variation method
incompletely.
Sample answer:
The height of precipitate formed will increased and remain
constant when lead(II) nitrate solution is added with potassiumchromate(VI) solution.
2
6
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Question Rubric Score
Able to state an idea of continuous variation method.
Sample answer:
Precipitate will formed when lead(II) nitrate solution is addedwith potassium chromate(VI) solution.
1
No response or wrong response 0
2 (f) Able to classify all the sixions correctly.
Sample answer:
Positive ion / Cation Negative ion / Anion
Pb2+ NO3-
K+
I-
H+ OH-
3
Able to classify any four ions correctly.
Sample answer:
Positive ion / Cation Negative ion / Anion
Pb2+ NO3-
K+ I-
2
Able to classify any two ions correctly.
Sample answer:
Positive ion / Cation Negative ion / Anion
Pb2+ I-
NO3+ K-
1
No response or wrong response 0
3 (i) Able to give the statement of the problem accurately by relating
the following four information:i. Position / distance
ii. Pair of metals // two metals
iii. Electrochemical series (ECS)
iv. Voltage
Sample answer:
How does position between two metals in the Electrochemical
3
7
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Question Rubric Score
Series affect the voltage?
Able to give the statement of the problem correctly by mention
i. position / distance // pair of metal
ii. ECS / Reactivity Seriesiii. Voltage
Sample answer:
Does the position of metals in ECS affect the voltage? //Does the position of electrode in Reactivity Series affect the
voltage? //
Does the distance of metals in ECS affect the voltage
2
Able to give an idea of statement of the problem correctly
Sample answer:Metals/electrode produces voltage.
1
No response or wrong response 0
3 (ii) Able to state all three variables correctly
Sample answer:
Manipulated variable: pairs of metals // two electrodesResponding variable: Voltage // voltmeter reading //
potential differenceConstant variable: Electrolyte // volume &
concentration of electrolyte //
metal as the positive / negativeterminal
3
Able to state any two variables correctly 2
Able to state any one variables correctly 1
No response or wrong response 0
8
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Question Rubric Score
3 (iii)
Able to state the relationship between the manipulated variableand the responding variable and state the direction
Sample answer:The further / nearer the distance of the two metals in
Electrochemical Series, the bigger / smaller the voltage.
3
Able to state the relationship between the manipulated variableand the responding variable without stating the direction
Sample answer:
The distance between metals in ECS affect the voltmeter reading
2
Able to state the idea of hypothesis correctly
Sample answer:
Different metal produces different voltage
1
No response or wrong response 0
3 (iv) Able to give complete list of substances and apparatusi. At least three metal below Ca in ECS
ii. Voltmeter
iii. Electrolyte, beaker, wire, sand paper
Sample answer:
Aluminium, zinc, copper, voltmeter, copper(II) sulphate solution,
beaker, connecting wires, sand paper
3
Able to state the following thingsi. At least two metal below Ca in ECS
ii. Voltmeter
iii. Electrolyte, container
Sample answer:Zinc, copper, voltmeter, copper(II) sulphate solution, beaker,
2
Able to state the following things
i. two metalsii. electrolyte
Sample answer:
1
9
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Question Rubric Score
Aluminium, zinc, sodium hydroxide solution
No response or wrong response 0
3 (v) Able to state the following six steps
1. Add/pour the electrolyte into a container2. Clean the metal strip with sandpaper
3. Dip both metals into the electrolyte
4. Connect the metals to the voltmeter// complete the circuit
5. Record the voltmeter reading6. Repeat step 1-5 by substituting one metal for another
3
Step 1 or 3, 4, 5, 6 2
Step 1 or 3 1
No response or wrong response 0
3 (vi) Able to exhibit the tabulation of data that includes the following
information:
1. Heading for manipulated variable
2. Heading for the responding variable with unit3. Examples of two pairs of metals
Sample answer:
Pair of metals Voltage / V
Zinc and copper
Iron and copper
3
Able to exhibit the tabulation of data that includes the following
information:1. Heading for manipulated variable
2. Heading for the responding variable without unit
3. Examples of one pairs of metals
2
10
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Question Rubric Score
Sample answer:
Pair of metals Voltage
Zinc and copper
Able to exhibit the tabulation of data that includes the following
information:
Heading for the (manipulated variable) / (responding
variable without unit)
Sample answer:
Pair of metals
1
No response or wrong response 0
END OF MARK SCHEME
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