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 A
D 33 C
9 D 34 B
10 B
C 35 D
11 D 36 D
12 D 37 D
A
13 B 38 C
14 D 39 A
15 B 40 B
16 A
C 41 B
17 C 42 A
C
18 D
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

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 = mcq
= 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
DH = - 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
X W X
Correct no of shells and electron for each atoms involved

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
Consist of molecules Consist of ions
Neutral particles Charged particles//Move freely
10 (a) Metal R: magnesium//zinc
Can conduct electricity in
molten and aqueous state
in molten and aqueous state
Reason: Metal R is more electropositive than iron// Iron nail does not
rust//prevent iron from rusting//inhibit rusting of iron nail
TOTAL 20
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
1
1
1
1
(b) Metal: magnesium // zinc// lead // tin
mark 6
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)
Carbon
electrode
Potassium
iodide
solution
Diagram:
1. label
2. functional apparatus
1
1
Carbon
electrode
Bromine water
Sulphuric acid
Suggested chemical:Potassium iodide solution
(or any suitable reducing agent)
1

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

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
1
If reverse
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
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
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
Sample answer
Pairs of Metal Voltage
Fe/P 2.2
Fe/Q 1.4
Fe/R 3.4
2
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
0
2(f) Able to construct a table that consists of:
Sample answer
Type of cleaning agent Observation/Effectiveness
Detergent
Soap
2
Sample answer
Type of cleaning agent Observation
1
0
PERATURAN PEMARKAHAN TAMAT

Kimia kedah trial_2014_with_answer

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