kimia kedah trial_2014_with_answer

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MODULE 2

CHEMISTRY 2014

KEDAH

PAPER 1 ANSWER

Question No. Answer Question No. Answer

1 B 26 A

2 A 27 A

3 D 28 B

4 A 29 A

5 C 30 C

6 D 31 B

7 A 32 C

8 D 33 C

9 D 34 B

10 C 35 D

11 D 36 D

12 D 37 A

13 B 38 C

14 D 39 A

15 B 40 B

16 C 41 B

17 C 42 C

18 A 43 C

19 A 44 A

20 C 45 C

21 C 46 B

22 C 47 D

23 A 48 B

24 A 49 D

25 B 50 C


KPM

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KPM

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Pencil

KPM

Typewritten text

A

KPM

Typewritten text

B

KPM

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A

KPM

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D

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D

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A

1

MARK SCHEME : PAPER 2 MODULE B: CHEMISTRY

Question No

Mark Scheme Marks

1 a) Empirical formula : formula that shows the simplest whole number ratio of atoms of each element in a compound

1

b) To allow oxygen from the air to react with magnesium // To prevent fumes of magnesium oxide from escaping

1

d) (i) Mass of magnesium = 19.20 - 18.30 g = 0.9 g Mass of oxygen = 19.80 - 19.20 g = 0.6 g

1

(ii) Elements Mg : O No of mole 0.9 : 0.6 24 16 Ratio 0.0375 : 0.0375 // 1 : 1 0.0375 0.0375

1 1

(iii) MgO 1 (e) (i) Cu // Pb // Sn 1 (ii) To remove all the air in the combustion tube 1 (iii) To dry the hydrogen gas // as a drying agent 1 Total 9

Question No

Mark Scheme Marks

2 (a) Contact Process 1 (b) Oleum 1 (c) SO3 + H2SO4 → H2S2O7 1 (d) 450-500 OC 1 (e) Air (udara) 1 (f) Nitric acid 1 (g) (i) Acid rain corrodes the buildings made of calcium carbonate/limestone//

Acid rain corrodes concrete building 1

(ii) Reduce combustion of fossil fuels Channel waste gases from factory through air filtering systems (accept any suitable answers)

1 1

Total 9


2

3 (a) Heat released when one mol of water produce from reaction between hydrochoric acid // acid and sodium hydroxide// alkaline solution.

1

(b)

(i) (ii) (iii)

Heat change = mcθ = 200 x 4.2 x 13 = 10 920 J = 10.92 kJ No. of mol of H+ = 100 x 0.2 1000 = 0.02 mol // No. of mol of OH- = 100 x 0.2 1000 = 0.02 mol Heat of neutralisation = 10920 0.02 = 546 000 Heat of neutralization = - 546 kJ mol-1

1 1 1

(c)

correct diagram

labelled

1

1

(d) (i) Between -533 kJ mol-1 to – 542 kJ mol-1 1

(ii) Ethanoic acid is a weak acid // ionise partially in water to produce hydrogen ion Some heat is absorbed for ionization of ethanoic acid.

1 1

Total 10

∆H = - 546 kJmol-1

3

5 (a) Sulphuric acid [r: H2SO4]

1

(b) H2SO4 + 2KOH � K2SO4 + 2H2O Correct formula reactant and product Balanced

1 1

(c) (i) Able to calculate the volume of Y(V1) acid used with unit M1V1 = M 2V2 a b 0.1 (V1) = 0.2(25) 1 2 V1 = 25 cm3 (r : without unit)

1 1

(ii) Able to calculate the mass of salt formed with unit Number of mol Y acid = MV 1000 = 0.1(25) 1000 =0.0025 Mass of salt formed= 0.0025 x 174

1

4 (a) Strong acid is an acid that ionises completely in water to produce high concentration of hydrogen ions.

1

(b) (i) Ethanoic acid 1 (ii) Ionise partially in water //produce low concentration of hydrogen ions. 1 (c) (i) 2 1 (ii) 10 x X = 250 x 0.02

X = 0.5 mol dm-3 1 1

(d) (i) water 1 (ii) H+ 1 (iii) Zn +2 HCl → ZnCl2 + H2

1.correct formula and reactant 2.balancing

1 1

Total 10

4

= 0.435 g (r : without unit) 1

(d) The solution is heated until saturated /one third of its original volume Cool the solution slowly The salt are filtered and dried by pressing them between filter papers.

1 1 1

(e) Sodium sulphate//Potassium nitrate//sodium nitrate//sodium chloride//potassium chloride

1

11 6 (a) Alkene / alkena 1 (b)

H H H I I I H – C – C – C – H I I I H H H

1

(c) (i) C3H6 + 9/2O2 � 3CO2 + 3H2O Correct formula of reactant and product Balance equation

2

(ii) Propene produce more soot % of C in propene is higher than that in propane % of C in propene; 3 X 12 X 100 = 85.71% 42 % of C in propane: 3 X 12 X 100 = 81.82% 44

1 1 1

(d) Propene is an unsaturated hydrocarbon but propane is saturated hydrocarbon // Propene has double bond but propane has single bond

1

(e)

Gambarajah berfungsi label

anak panah : heat

1 1 1

Glass wool

soaked with

propanol

5

TOTAL 11

Section B

7 (a) (i) 1.No of mole of helium atoms= 4 mol //1 mol 4 2. No of mole of hydrogen atoms = 2 x 2mol //2 mol 2

1 1

(ii) 1.No of atom of hydrogen is double/twice than helium 2.because no of mole of atom of hydrogen is double/twice than helium

1 1

(b) (i)

Empirical formula = C5H7 N Molecular Formula = C10 H14 N2

C5H7 N C10 H14 N2

both contain element carbon,hidrogen and nitrogen

Contain 5 carbon atoms,7 hidrogen atoms and 1 nitrogen atom

Contain 10 carbon atoms,17 hidrogen atoms and 2 nitrogen atom

Shows simplest whole number ratio of atom of each element

Shows actual number of atom of each element

1 1 1

1+1

1+1

(ii) 1.brown bromine water decolourises 2.nicotine undergoes addition reaction with bromine//c=c react with bromine

1 1

(c) (i) Wrong formula 1. AgCl2 2. Mg NO3

1 1

(ii) 2AgNO3 + MgCl2 → 2AgCl + Mg(NO3)2 1.correct formula of reactant and product 2.correct balancing

1 1

(iii) 1. silver nitrate and magnesium chloride are reactants and silver chloride and magnesium nitrate are products 2. silver nitrate , magnesium chloride and magnesium nitrate are in aqueous solution but silver chloride in solid form 3. 2 mole of AgNO3 react with 1 mole of MgCl2 to form 2 mole of AgCl and 1mole of Mg(NO3)2 (Note : point 3 ecf from (c)(ii))

1 1 1

Total 20


6

8(a) (i) 2H2O2 � 2H2O + O2

Correct formula balanced

1 1

(ii)

Correct curve axis and units

label expt(A,B) and time (20,40)

1 1 1

(iii) i) Increase the concentration of hydrogen peroxide 1 ii) 0.1 mol dm-3 / any suitable higher concentration 1

iii) Volume 25 cm3 / any suitable volume to get that match the concentration

1

iv) Any suitable application of concentration. 1

v) How the application is used. 1

(iv)

functional diagram Labelled

1 1

EkspB

Eksp A

20 40

7

(c) (i) 1. Rate of reaction of experiment B is higher 1

2. The presence of catalyst in experiment B 1

3. the reaction through the alternative path // lower activation energy 1

4. more colliding particle can achieve the lower activation energy 1

5. frequency of effective collision is higher. 1

(c) (ii)

Correct graph

Label experiment (A,B)

Label activation energy

1

1

1

Total 20

Section C

9 a) i.

Ionic: Y and X// Y and Z// Y and W Covalent: W and X//W and Z //X and Z

1 1

ii

Ionic: Between Y and X

Eksp B

Eksp A

Activation

energy

X

2-

Y

+

Y

+


8

ii.

or Between Y and Z

Covalent

Correct no of shells and electron for each atoms involved

X W X

9

Correct no of atoms// charge for each compund

1x2 1x2

ii

Explain: Between element Y and X(sample for ionic)

Atom Y has 1 valence electron and atom X has 6 valence electron 2 Atom of Y donate 1 electron each to form 2Y+ ion // 2Y � 2Y+ + 2e

Atom X accept 2 electron to form X2- ion // X + 2e � X2- To achieve stable octet electron arrangement

2 ion Y+ and ion X2- attract each other by a strong electrostatic forces // Y2X ionic compound is formed

Between element W and X (WX2)(sample for covalent)

One atom W contribute 4 electrons Four atom Z contribute 1 electron to share.

One atom W share 4 pairs electron with four atom Z Four single covalent bond are formed

WZ4 covalent compound is formed

1

1 1 1 1 1 1 1 1 1 1

Maximum mark 12 b)

Covalent Compound Ionic Compound d

Low melting and boiling points High melting and boiling points Held by weak intermolecular forces

Held by strong electrostatic forces

Need more energy to overcome the forces

Need less energy to overcome the forces

or

1+1 1+1 1+1

Covalent Compound Ionic Compound Cannot conduct electricity in any state

Cannot conduct electricity in solid state

1+1

10

10 (a) Metal R: magnesium//zinc Reason: Metal R is more electropositive than iron// Iron nail does not rust//prevent iron from rusting//inhibit rusting of iron nail Metal S: copper//tin//lead//silver//aurum Reason: Iron is more electropositive than metal S// Iron nail rusts//speed up rusting (accept any suitable metal R and S)

1 1 1 1

(b) Metal: magnesium // zinc// lead // tin Eg: Oxidation nombor of Mg increases from 0�+2 //Mg� Mg2++2e Magnesium undergoes oxidation Oxidation nombor of copper(II) ion decreases from +2� 0// Cu2+ +2e � Cu Copper undergoes reduction Redox reaction occurs as oxidation of magnesium and reduction of copper(II) ions occur simultaneously.

1 1 1 1 1 1

(c)

Diagram: 1. label 2. functional apparatus

1 1

Suggested chemical:Potassium iodide solution (or any suitable reducing agent)

1

Can conduct electricity in molten and aqueous state

Consist of molecules Consist of ions Neutral particles Charged particles//Move freely

in molten and aqueous state

1+1 1+1

mark 6 TOTAL 20

Carbon electrode

Potassium iodide solution

Carbon electrode

Bromine water

Sulphuric acid

11

Procedure: 1. Dilute sulphuric acid is poured into a U-tube. 2. Using a dropper, potassium bromide solution is added at one arm

and bromine water at another arm. 4. Carbon electrode is placed in each side of the U-tube. 5. The electrodes are connected to a galvanometer by using connecting wires// The external circuit is completed. 6. Any changes that can be observed are recorded. Half-equations: 2I- → I2 + 2e Br2 + 2e → 2Br-

1 1 1 1 1 1 1

Max 10

Total 20

END OF MARK SCHEME http://cikguadura.wordpress.com/

1

MODULE B :KIMIA PAPER 3: Mark Scheme

Questions Mark Scheme Mark 1(a) Able to state the three variables correctly

Sample answer - Manipulated Variable: metals in contact with Fe//P,Q,R - Responding Variable: rusting//blue spots//pink spots - Constant Variable: iron nail//electrolyte -

3

Able to state any two variables correctly

2

Able to state any one variables correctly

1

No response or wrong response

0

1(b) Able to state the relationship between the manipulated variable and the responding variable and state the direction correctly. Sample answer The further the distance between two metals in electrochemical series, When less electropositive metal in contact with iron, the higher is the intensity/more of blue spots/rust

3

Able to state the relationship between the manipulated variable and the responding variable without stating the direction Sample answer When different metal in contact with iron, the more blue spot/rust formed

2

Able to give an idea of hypothesis Sample answer Pair of metal willproduce rust.

1


0

1(c)

Able to make inference correctly. Sample answer

Set Inference I Metal P is less elctropositive than iron II Metal Q is the most electropositive. III Metal R is more electropositive than iron

3

Able to state 2 inference correctly

2

Able to state 1 inference correctly 1


0

1(d) Able to give the operational definition for rusting correctly with the 3


2

following aspects: i.what you do ii.what you observe Sample answer When less electropositive metal in contact with iron, blue spot form

Able to give the operational definition for rusting incompletely with any

one of the following aspects: i.what you do ii.what you observe Sample answer Metal is put into jelly blue spot form

2

Able to give an idea of operational definition for rusting Sample answer Metal rust

1


0

1(e) Able to compare the difference between 1 day and 2 days correctly Sample answer The size/quantity of blue spot increase with time

3

Able to compare the difference between 1 day and 2 days Sample answer More blue spot form

2

Sample answer Blue spot form

1


0

1(f) Able to arrange the four metals correctly Sample answer P, Fe, R, Q

3

Able to arrange any three metals in sequence correctly Sample answers Fe, R, Q , // P, Fe, R

2

Able to arrange any two metals correctly Sample answers P, Fe// Fe, R// R, Q

1


0

1(g) Able to predict the metal correctly

Sample answer Copper/Cu // Silver/Ag

3

Able to predict the metal less correctly Sample answer

2

3

Gold/Au

Able to give an idea of predicting the metal Sample answer Mercury/Hg

1


0

1(h) Able to classify all the six metals correctly Sample answer

Metal which are more electropositive than iron Logam yang lebih elektropositif daripada besi

Metal which are less electropositive than iron Logam yang kurang elektropositif daripada besi

Magnesium Aluminium Zinc

Copper Tin Silver

3

Able to classify any 4 metals correctly 2 Able to classify any two metals correctly

If reverse 1


0

1(i) Able to state all observations correctly Sample answer

Electrode/Electrolyte Elektrod/Elektrolit

Observation Pemerhatian

Negative terminal Terminal negatif Positive terminal Terminal positif Electrolyte Elektrolit

Becomes thinner//corrodes Becomes thicker// brown solid deposited. Intensity of blue colour decreases//blue to light blue

3

Able to state any two observations correctly 2 Able to state any one observation correctly 1 No response or wrong response

0

1(j) Able to record all readings accurately with one decimal place and unit Answer Set I : 2.2 V Set II : 3.4 V Set III : 1.4 V

3

Able to record all readings correctly without unit or any two readings correctly with unit. Sample answer Set I : 2.2 //2.20 Set II : 3.4 // 3.40

2

4

Set III : 1.4 // 1.40 Able to record at least one reading 1 No response or wrong response

0

1(k) Able to construct a table that consists of: 1.Headings for manipulated and responding variables with unit 2. List all the variables Sample answer

Pairs of Metal Voltage (V) Fe/P 2.2 Fe/Q 1.4 Fe/R 3.4

3

Able to construct a table that consists of: 1.Headings for manipulated and responding variables without unit 2. List all the variables Sample answer

Pairs of Metal Voltage Fe/P 2.2 Fe/Q 1.4 Fe/R 3.4

2

Able to construct a table that consists of: 1.Headings for manipulated and responding variables Sample answer

Pairs of Metal Voltage

1


0

2(a) Able to give the problem statement correctly Sample answer Does soap more effective than detergent for cleansing action in hard water?

3

Able to give the problem statement Sample answer Does soap more effective than detergent ?

2

Able to give an idea of the problem statement. Sample answer Does soap more effective ?

1


0

2(b) Able to state all variables correctly Sample answer Manipulated variable: Detergent ,soap Responding Variable: effectiveness of cleansing action Fixed variable : hard water//mass/volume of detergent and

3

5

soap//volume of water Able to state any two variables correctly

2

Able to state any one variable correctly

1


0

2(c) Able to state the hypothesis correctly Sample answer Detergent is more effective than soap in hard water

3

Able to state the hypothesis Sample answer Detergent is more effective

2

Able to give an idea of the hypothesis Sample answer Detergent is for cleaning action

1


0

2(d) Able to list the materials and apparatus completely Sample answer Materials 1. dirty cloth/socks 2. soap and detergent 3. hard water Apparatus

1. Beaker/basin 2. Measuring cylinder 3. Spoon/spatula

3

Able to list the materials and apparatus Sample answer Materials 1. cloth 2. soap and detergent 3. hard water Apparatus

4. Beaker/basin/container

2

Able to give an idea of materials and apparatus Sample answer 1. detergent/soap 2. cloth 3. water

1


0

2(e) Able to state all steps of procedure correctly Sample answer 1.Pour 100-200 ml of hard water into a beaker 2. Add/put 1-2 spoon of detergent into the beaker 3. Soak/dip a dirty cloth in the beaker 4. Leave for 30 minutes 5.Record the observation 6. Repeat steps 1-5 using soap.

3

Able to state the steps 1,2,3 and 5 2

6

Able to state steps 1.2 and 3 1 No response or wrong response

0

2(f) Able to construct a table that consists of: 1.Headings for manipulated and responding variables 2. List all the variables Sample answer

Type of cleaning agent Observation/Effectiveness Detergent Soap

2

Able to construct a table that consists of: 1.Headings for manipulated and responding variables Sample answer

Type of cleaning agent Observation

1


0

PERATURAN PEMARKAHAN TAMAT


kimia kedah trial_2014_with_answer

Education

d i water

ih c c c hi

b i ethanoic acid

mol of water

mol of h

g i acid rain

i 2h2o22h2o

kj mol