Kimia P3 Sbp Mid Year Spm 2008

Nama : ……………………………………………...

Kelas : …...……

4541/3 Kimia Kertas 3 Mei 2008 1½ Jam SEKTOR SEKOLAH BERASRAMA PENUH KEMENTERIAN 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.

Untuk Kegunaan Pemeriksa Soalan

Markah Penuh

1

18

2

15

3

17

JUMLAH

50

Markah Diperoleh

Kertas soalan ini mengandungi 9 halaman bercetak

SULIT 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

4541/3

Description

3

Excellent

: The best response

2

Satisfactory : An average response

1

Weak

0

No response or wrong response

: An inaccurate response

2

SULIT

SULIT 1.

An experiment was conducted to find out the effect of temperature on the rate of reaction. 50 cm3 of sodium thiosulphate solution 0.2 mol dm-3 at 30 oC was put into a 150 cm3 conical flask. Then the conical flask was placed on an “X” sign on a piece of white paper. 5 cm3 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 35oC, 40oC, 45oC and 50oC. Diagram 1 shows the reading of the stop watch for each of the reaction at different temperatures.

Time ,t1 ……… at 30 o C

Time ,t2 ……… at 35 o C

Time ,t4 ……… at 45 o C

Time ,t3 ……… at 40 o C

Time ,t5 ……… at 50 o C Diagram 1

(a)

Record the time for each reaction in the spaces provided in Diagram 1. [3 marks]

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SULIT

SULIT (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)

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

4

SULIT

SULIT Graph of temperature against 1/ time

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SULIT

SULIT (ii)

Based on the graph in (d) (i), state the relationship between the rate of reaction and 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:

………………………………………….

……………………………………..……………….

………………………………………….

…………………………..………………………….

………………………………………….

………………………..…………………………….

Table 1.1

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[3 marks]

SULIT

SULIT 2.

The pupil carried out an experiment to construct the electrochemical series of metals using 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. V

Y

Cu

Copper(II) sulphate solution

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

Experiment

Pair of metals Y electrode

Reading of voltmeter

Positive electrode

(V)

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 ]

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SULIT

SULIT (ii)

Based on the change in size that you observed at the magnesium electrode after 30 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 copper in 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

SULIT 3.

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

Beaker A

Beaker 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

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SULIT

SULIT 4541 Chemistry Marking Scheme Mei 2008

4541/1/2/3

BAHAGIAN SEKOLAH KEMENTERIAN PELAJARAN MALAYSIA ______________________________________________ PEPERIKSAAN PERTENGAHAN TAHUN 2008

FORM 5 CHEMISTRY MARKING SCHEME FOR PAPER 1, 2 AND PAPER 3

Peraturan pemarkahan ini mengandungi halaman bercetak.

1

PAPER 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

B C B C D A B A D D D C A A C B C C C C

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

2

D D B A C A D A C A A B D A C A D B B D

41 42 43 44 45 46 47 48 49 50

D B D C B A B D C B

PAPER 2-SECTION A No. 1

Rubric a

Mark

G

1

Has stable /octet electron arrangement//8 valence electron

1

2A + 2H2O  2AOH + H2

1

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

1

c

G,E,D, A,J,L

1

d

Has same valence electron// valence electron is 1

1

e (i)

DE2 r: E2D

1

b (i) (ii)

(ii)

[can draw the diagram of electron arrangement correctly] - Correct structure of atoms - Correct ratio of atoms=1:2

2

Has (neutral ) molecule

1

TOTAL

10

a

T1

1

b(i)

PQ: solid + liquid

1

RS: liquid

1

Heat energy absorbed

1

is used to overcome the forces of attraction between particles

1

(iii)

2

(ii) c

// Heat is absorbed to overcome the intermolecular forces r: ion/atom (1+1) d

The particles / molecules move faster

1

e (i)

Iodine/I2//napthalene/C10H8

1

(ii)

Copper/ Cu

1

(iii)

Ion

1

Diffusion

1

TOTAL

10

3

3

a (i)

3H2 + N2  2NH3

1

(ii)

( Extract from ) air

1

Neutralization

1

H2SO4+ 2NH3  (NH4)2SO4

1

b (i) (ii)

//H2SO4+ 2NH4OH  (NH4)2SO4 + H2O (iii) c (i)

Fertilizer

1

Tin

1

(ii)

Copper atom

Tin atom

Copper atom

(1+1) 

d

In pure copper the layer of atom are easily slide over each other when external force is applied on them.



1

The different size of foreign atoms in allloy are prevent the layers of atom from slide each other when external force is

1

applied.

4

a

TOTAL

10

1 Diagram of set up of apparatus complete and functional

1

2 Label (Anode) – impure copper and (cathode )– pure copper

1

3 ( Electrolyte) – copper (II) sulphate / copper (II) chloride // copper (II) nitrate solution

1

a: chemical formula

b(i)

(ii)

1 become thinner // decrease in mass

1

2 become thicker // increase in mass

1

1 ( Remain )unchanged

1

2 Number of Cu2+ ions produced at anode same as number of copper atoms produced at cathode // the rate of formation of Cu2+

4

ions at the anode is the same as the rate of discharge of Cu2+ at cathode.

c (i) (ii)

d

5

1

(Anode ):Cu  Cu2+ + 2e (Cathode ): Cu

2+

1

+ 2e  Cu

1

Electroplating of metals/ Extraction of reactive metals

1

TOTAL

10 

a

2H2O2

b

Number of mole of H2O2 = 20 x 2/1000= 0.04

O2 + 2H2O

1

1

2 mol of H2O2 produce 1 mol of O2 // Number of mole of O2 = 0.04/2 = 0.02

1

Volume, O2 = 0.2 x 24dm3 = 4.8 dm3 c (i) (ii)

1

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

d

1 1 1



The frequency of collision between H2O2 molecule is higher



The frequency of effective collision is higher

1

Volume of gas/cm3

II I

Time(s) Label Y axes and X axes Correct curve and label I and II

1 1

10

TOTAL

5

6

A compound that contain element of carbon and derive from living

a

1

organisms.

C2H4

1

(ii)

ethene

1

(iii)

double bond between carbon atoms

1

b (i)

(a: C=C ) c (i)

Acidified potassium manganat (VII) // Acidified potassium

1

dicromate (VI) (ii)

Oxidation

1

(iii)

Purple to colourless // orange to green

1

C2H4 + H2O  C2H5OH

1

(ii)

Alcohol

1

(iii)

Temperature 300 oC // Pressure 60 atmosphere // concentrated

d (i)

phosphoric acid

1

TOTAL

10

6

SECTION B No. 7

Rubric a (i)

Mark

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

1

(ii) Compound that form between non metal atom by sharing their valence electron to achieve stable/octet /duplet electron

1

arrangement

b

Between P and Q  

Atom X has 1 valence electron

1 +

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//

1 1 1

Y + e-Y

attain the stable /octet electron arrangement



The two oppositely-charged ions// the X+

1

and Y- ion are

bonded together by a strong electrostatic force 

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

X Y

Max 7

7

1 1

(ii)

Between Y and Z 

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

1

electrons 

One atom Z contributes 4 electrons and (each) atom Y 1

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

1 1 1

Y

Z

Y

Y

Y

(iii) 

Magnesium oxide is an ionic compounds



Strong electrostatic force of attraction exists between

1

1

Mg2+ and O2 -// 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

1



Tetrachloromethane is a covalent compound

1



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

1

Waals) force of attractions between molecule 

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

8

1

8

a

TOTAL 20 Empirical formula- Formula shows simplest ratio of atoms of each 1 element in the compound Molecular formula- Formula shows actual number of atoms of each element in the compound

b

Molecular Formula = ( Empirical formula )n = ( CH2 )n Relative Molecular Mass ( CH2 )n = 70 12n + 2n= 70 14n=70 n=5 Molecular Formula C5H10

c(i)

1

1

1 1

1. Metal Z is cleaned using sand paper

1 2. A crucible and its lid are weighed and the mass is recoded 1 3. Metal Z is palced in the crucible. The crucible,lid and its content is weighed and the mass is recorded.

1

4. The crucible with its content is heated strongly without lid.

1

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

1

6. the covered is raise a little at intervals

1

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

1 1

Content and record the mass. 9. The process of heating, cooling and weighing is repeated

1

until constant is obtained. 10. (Precaution step ); Close the crucible immediately to prevent loss of

9

1

Element

Z

O

Mass(g)

1.30

0.32

1

1 mol

1.30/65=0.02

0.32/16=0.02 1

Simplest ratio

1

1 1

Empirical Formula ZO

1

TOTAL

20

10

PAPER2 –SECTION C Rubric

No 9

Mark

Sample answer :

a

Zn + HNO3 

Zn(NO3)2 + H2O

ZnCO3 + HNO3  Zn(NO3)2 + H2O + CO2 ZnO + HNO3  Zn(NO3)2 + H2O

b (i)

(ii)

c(i)

Any two

2



Methanoic acid partial ionizes in water

1



produce low concentration of hydrogen ion

1



Glacial ethanoic acid has (neutral) molecule

1



Methanoic acid aqueous ionizes in water

1



to produce free moving ion

1

Procedure : 1 100 cm3 of 0.1 moldm-3 sulphuric acid is poured into a beaker

1

and heated slowly. 2 zinc carbonate is added into the sulphuric acid until in excess/no longer dissolves.

1

3 Stir the solution and filtered.

1

4 The filtrate is poured into an evaporating dish and heat until saturated

1

5 The hot saturated salt solution is allowed to cool 1 6 The crystals formed are filtered out, rinsed with distilled water 7 dried between sheets of filter paper.

11

1

(ii)

ZnCO3 + H2SO4  ZnSO4 + H2O + CO2

1

Number of mole , H2SO4 = 0.1( 100 )/1000 = 0.01

1

1 mol of H2SO4 produce 1 mol of ZnSO4 1

Mole of ZnSO4 = 0.01 Mass of ZnSO4 = 0.01 X 161 = 16.1 g Sample answer :

d

1 ammonium chloride as a fertilizer 2 copper (II) sulphate as a pesticide 3 hydrated calcium sulphate to make plaster casts 4 sodium chloride food additive Any 2 suitable anwers(1+1) TOTAL 10a

1

(i) (ii) (iii)

1 1

20

catalyst

1

esterification

1

CH3COOH + C3H7OH  CH3COOC3H7 + H2O

1

Correct reactant Correct product

1

(iv)

Ethyl propanoate Sweet smell/fruity smell/fragrant smell //insoluble in water/soluble in organic solvent //colourless //less dense than water

2

any two properties (1+1) (v)

2

12

 b

(i)

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 broken



1 1

Rubber polymer are released and lump together 1



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

(ii)



1 1

The presence of cross-linkage of sulphur atoms between the rubber molecule



1

1

When vulcanized rubber is stretched and release, the crosslinkage will pull the chain back to their original arrangement

1



Diagram



Improves the elasticity and strength of the rubber / make

1

vulcanized rubbers more resistant to heat /organic solvent 1

 or Resistant to oxidation : 

The presence of cross-linkage of sulphur atoms between the rubber molecule

1



Diagram



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

1

unvulcanized rubber, 

1

so vulcanize rubber is more resistant to oxidation 1 TOTAL 20

13

PAPER 3 1 (a) KK0503 – Measuring and using numbers EXPLANATION [Able to write all the times with units accurately] Suggested answer:

SCORE 3

t1 55.0 s, t2 48.0 s , t3 42.0 s , t4 37.0 s , t5 33.0 s [Able to record all the times accurately but without units / no decimal place] t1 55.0 , t2 48.0 , t3 42.0 , t4 37.0 , t5 33.0 // // t1 55 s , t2 48.0 s , t3 42 s, t4 37s, t5 33s

2

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

1

No response given / wrong response

0

1 (b) KK0501- Observation EXPLANATION [Able to state the colour of sulphur and the rate of it is formed] Suggested answer:

SCORE 3

Pale / light yellow precipitate is slowly formed [Able to state the colour of sulphur] Pale / light yellow precipitate is formed. [Able to state the formation of precipitate] A precipitate is formed. No response given / wrong response

2 1 0

1 (c) KK0506 – Communicating EXPLANATION [Able to construct a table correctly containing three labeled columns with correct units and record all the time and 1/time accurately ]

SCORE

Suggested answer: Temperature, o C Time , s 1 / time , s-1

30

35

40

45

50

55.0 0.018

48.0 0.021

42.0 0.024

37.0 0.027

33.0 0.030

3

[Able to construct a table correctly containing three labeled columns with correct 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 14

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

SCORE 3

1. Both axes labeled and units ( Y axis - temperature , X axis – 1/ time ) 2. All points transferred correctly 3. Uniform scale, graph size covers at least half of the graph paper. 4. Straight line/ best fits drawn [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 correctly 3. 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 Operationally EXPLANATION [Able to interpret the relationship between the rate of reaction and the temperature of sodium thiosulphate solution from graph accurately] Suggested answer: The rate of reaction is directly proportional to the temperature of sodium thiosulphate solution // As the temperature of sodium thiosulphate increases the rate of reaction increases. [Able to interpret the relationship between the rate of reaction and the temperature 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 the temperature increases. [Able to state an idea of hypothesis The temperature affects the rate of reaction. No response given / wrong response

SCORE 3

2

1

0

15

Temperature /oC

50

X

45

X

40

X

35

X

30 X 0.015

0.020

0.025

16

0.030

1/time , s-1

1(e) KK0510 - State variables EXPLANATION [Able to state three variables and three action to be taken] Suggested answer: Variable Manipulated: Temperature

Action to be taken Heat the sodium thiosulphate solution at different temperature // Use different temperature. Record the time taken for “X” mark to disappear from view.

SCORE

3

Responding: Rate of reaction / time taken for “X” marks to disappear from view. Controlled : Use the same concentration and Concentration and volume of H2SO4, volume of H2SO4 /sodium concentration and volume of sodium thiosulphate solution // Use same thiosulphate solution, size of conical size conical flask. flask. [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 [Able to write the correct overall ionic equation] Suggested answer: Mg + Cu2+  Mg2+ + Cu Mg + CuSO4  MgSO4 + Cu Mg  Mg2+ + 2e // Cu2+ + 2e  Cu No response given / wrong response

SCORE 3

2 1 0

2(a)(i) KK 0504 – Making inference EXPLANATION [Able to state the correct inference] Suggested answer: Magnesium atom releases/donate/loses electrons to produce magnesium ion // Magnesium is corrode. Magnesium becomes thinner // mass of magnesium decreases Magnesium dissolves No response given / wrong response

17

SCORE 3

2 1 0

2(b) KK 0505 - Predicting EXPLANATION [Able to state the voltage value] 0.65 V 0.63 – 0.64 V // 0.66 – 0.67 V < 0.64 V // > 0.67 V No response given / wrong response 2(c)KK 0508 – Interpreting Data EXPLANATION [Able to arrange the position of all metals in an ascending order based on tendency to release electrons correctly] Copper > Lead > Iron > Zinc > Magnesium

SCORE 3 2 1 0

SCORE 3

[Able to arrange the position of all metals in descending order based on tendency 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 definition EXPLANATION [Able to state the correct and complete operational definition] Suggested answer:

SCORE 3

The further the metal is from copper in the electrochemical series, the greater is their voltage reading. // [Able to give incomplete relationship] Suggested answer:

2

The further apart the metal is in the electrochemical series, the greater the potential difference / voltage reading. [Able to state an idea] Suggested answer:

1

The position of metal influence the voltage reading // Type of metal influence the voltage reading. No response given / wrong response

0

18

3.(a) KK051021 – Statement of problem EXPLANATION [Able to make a suitable statement of problem] Suggested answer: How to differentiate between magnesium nitrate solution and calcium nitrate solution // How to differentiate between magnesium ion and calcium ion [Able to make a suitable aim] Suggested answer:

SCORE 3

2

To differentiate the presence of magnesium ion and calcium ion by using aqueous ammonia solution. [Able to state an idea of statement of problem or aim]

1

No response given / wrong response

0

3(b) KK051202 – Stating hypothesis EXPLANATION [Able to state the relationship between manipulated variable and responding variable correctly] Suggested answer: If the addition of aqueous ammonia solution forms white precipitate which is insoluble in excess ammonia aqueous solution, then the solution tested is magnesium nitrate. // If aqueous ammonia solution is added and no change occur then the solution tested is calcium nitrate. [Able to state the relationship between manipulated variable and responding variable] [Able to state an idea of the hypothesis] No response given / wrong response

SCORE 3

2 1 0

3 (c) KK051202 – Stating variables EXPLANATION [Able to state all the three variables correctly] Suggested answer: Manipulated variable : magnesium nitrate and calcium nitrate // Mg2+ and Ca2+ Responding variable: formation of white precipitate Controlled 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

19

SCORE

3(d) KK051205 – List of substances and apparatus EXPLANATION [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 nitrate solution, aqueous ammonia solution. [Able to state the list of substances and apparatus correctly but not completely] Suggested answer: Test tube 0.5 mol dm-3 magnesium nitrate solution, 0.5 mol dm-3 calcium nitrate solution, aqueous ammonia solution. [Able to state an idea about the list of substances and apparatus] Suggested answer: Test tube magnesium nitrate, calcium nitrate No response given / wrong response

SCORE 3

2

1

0

3(e) KK051204 – Technique /Precedure EXPLANATION [Able to state a complete experimental procedure] Suggested answer: 1. 2 cm3 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 excess 4. The mixture is shaken well. 5. The changes occur is recorded in a table. 6. Steps 1 to 4 are repeated using solution B.

SCORE 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 No response given / wrong response

1

20

0

3(f) Tabulation of data EXPLANATION [Able to exhibit the tabulation of data correctly ] Reagent

SCORE

Observation Test tube/Solution A Test tube/Solution B

Aqueous ammonia solution

3

[Able to exhibit the tabulation of data less accurately ] Reagent Aqueous ammonia solution

Test tube /Solution A

2 Test tube/Solution B

[Able state an idea about the tabulation of data]

1

No response given / wrong response

0

END OF MARKING SCHEME

21