chemist marking scheme (main)1
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7/31/2019 Chemist Marking Scheme (Main)1
1/23
BAHAGIAN KURIKULUM TEKNIK DAN VOKASIONAL
KEMENTERIAN PELAJARAN MALAYSIA
1 MALAYSIA : RAKYAT DIDAHULUKAN, PENCAPAIAN DIUTAMAKAN
BENGKEL
PEMBINAAN MODUL
PECUTAN AKHIR SPM2009
CHEMISTRYCHEMISTRY
MARKING SCHEMEMARKING SCHEME
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BAHAGIAN KURIKULUM TEKNIK DAN VOKASIONAL
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OBJECTIVE QUESTION
1 C2 D
3 A
4 B
5 A
6 A
7 B
8 C
9 C
10 A
11 D
12 B
13 D
14 C
15 D
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MODULE 1MODULE 1
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BAHAGIAN KURIKULUM TEKNIK DAN VOKASIONAL
KEMENTERIAN PELAJARAN MALAYSIA
PAPER 2
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1. The table 1 shows the proton number of P, Q, R ,S and T . Based on the table answer thefollowing questions.
Jadual 1 menunjukkan nombor proton bagi P,Q,R, S dan T. Berdasarkan jadual jawab
soalan berikut.
Element Proton Number
P 3
Q 8
R 9
S 18
T 19
TABLE 1
(a) (i) Write the electron arrangement for the element T .Tuliskan susunan elektron bagi unsur T.
2.8.8.1
[1 mark]
(ii) Determine the position of T in the Periodic Table of elementsTentukan kedudukan unsur T dalam jadual berkala.
Group 1 and period 4
[1 mark]
(b) Name the elements that are placed in the same group in the Periodic table of
elements.Namakan semua unsur yang berada dalam kumpulan yang sama dalam jadual
berkala.
Element P and Element T
[1 mark]
(c) Which element is known as a noble gas ?
Unsur yang manakah dikenali sebagai gas adi ?
Element S
[1 mark]
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2
Figure 1 below shows a portion of the Periodic table with elements Q,R,T ,X Y and Z .
The letters do not represent the symbol of the elements.Rajah 1 menunjukkan jadual berkala dengan unsur-unsur Q,R,T,X,Y dan Z.
Huruf-huruf tidak menunjukkan simbol yang sebenar bagi unsur.
FIGURE 1
(a) Using the alphabets in the table answer the following questions.
Dengan menggunakan huruf-huruf didalam jadual jawab soalan berikut.
(i) Which element is a halogenUnsur yang manakah adalah halogen.
Element Y
[1 mark]
(ii) Which element exist as a mono atomUnsur manakah adalah mono atom
Element R
[1 mark]
(b) Write the electron arrangement for Q
Tuliskan susunan electron bagi Q2.4
[1 mark]
(c) Write the formula of the ion formed from Y.
Tuliskan formula ion yang terbentuk dari atom Y.
Y-1
[1 mark]
(d) What is the name of the group of elements where Z is placed?
Apakah nama kumpulan dimana unsur Z diletakkan.
Transition element
[1 mark]
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Group
Period
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(e)
Based on the above information, which gas is more suitable to be used in
meteorological balloons?Berdasarkan maklumat yang diberi, gas yang manakah lebih sesuai digunakan
didalam belon kaji cuaca.
Helium gas
[1 mark]
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Helium gas
Gas Helium
Light
ringan
not reactive
tidak reaktif
colourless
tidak berwarna
Hydrogen gas
Gas hidrogen
Lightringan
Flammable
Mudah terbakar
Colourless
Tidak berwarna
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PAPER 3
1. Diagram below shows the chemical symbols which represent three elements X,Y and Z. X,Y and Z is not the actual symbol of the elements.
Rajah dibawah menunjukkan simbol kimia yang mewakili unsur X,Y dan Z. X,Y dan Z
bukan simbol sebenar bagi unsur.
(a) Write the electron arrangement of atoms X, Y and Z.Tuliskan susunan elektron bagi atom X, Y dan Z [ 3 marks]
X - 2.4
Y 2.6
Z 2.8.8.1
(b) Explain what is meant by the numbers 12 and 6 in the chemical symbol of element X.
Apakah yang ditunjukkan dengan nombor 12 dan 6 pada simbol kimia bagi unsur X[ 2 marks ]
in atom X , 12 is stand for nucleon number while 6 is a proton number.
(c) State the number of neutrons in an atom of atom Y.
Tentukan bilangan neutron bagi atom Y [1 mark]
Neutron - 8(d) (i) State the group of atom Z
Tentukan kumpulan bagi atom Z [1 mark]
Group 1
(ii) State the period of atom Z
Tentukan kala bagi atom Z [1 mark]
Period 4
(iii) Explain the reason for the answers in (d)(i) and (d)(ii).
Berikan alasan bagi jawapan anda di (d)(i) dan (d)(ii). [2 mark]
Group 1 because electron valens is 1
Period 4- because has 4 shells filled with electrons
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12
X6
16
Y8
39
Z19
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OBJECTIVE QUESTION
1 B 6 C
2 C 7 C
3 D 8 C
4 C 9 A
5 A 10 B
PAPER 2
1. Table 1 shows the proton number and nucleon number for atoms U, Vand W.
Jadual 1 menunjukkan nombor proton dan nombor nukleon bagi atom U, V dan W.
Atom Proton number Nucleon number
U 16 32
V 17 35
W 17 37
Table 1
a) What is meant byproton number?Apakah yang dimaksudkan dengan nombor proton?
The number of protons in the nucleus of an atom.
[1 mark]b) What is the number of neutron in atom ofV?
Berapakah bilangan neutron dalam atom V?
18.
[1 mark]
c) Which atoms are isotopes? Explain your answer.Atom-atom yang manakah adalah isotop? Terangkan jawapan anda.
V and W. Both the atoms have the same number of protons but different
number of neutrons.[2 marks]
d) i. Write the electron arrangement for atom U.Tuliskan susunan elektron bagi atom U.
2.8.6
[1 mark]
ii. Draw the electron arrangement for atom U.
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MODULE 2MODULE 2
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Lukiskan susunan elektron bagi atom U.
[2 marks]
2. Diagram 1 shows the chemical symbols which represent three elements X, Y and Z.
Rajah 1 menunjukkan simbol yang mewakili tiga unsur X, Y dan Z.
Diagram 1
b) Element X and Y react to form an ionic compound while element Z and Y react
to form a covalent compound. Describe the formation of the chemicalcompounds between
Unsur X dan Y bertindak balas untuk membentuk sebatian ionik, manakala
unsur Z dan Y bertindak balas untuk membentuk sebatian kovalen . Huraikanpembentukan sebatian kimia antara
i. element X and Yii. element Z and Y
Guided answer;
i. Formation of ionic compound between element X and Y.
Atom X has an electron arrangement of 2.8.1
Atom Y has the electron arrangement of 2.8.7
One atom of X donates one electron to form ion X+ to achieve a stable (octet)electron arrangement.
One atom of Y receives one electron to form ion Y- to achieve a stable (octet)
electron arrangement.
Ion X+ and ion Y- are attracted together by the strong electrostatic forces to
form an ionic compound with the formula XY.
ii. Formation of covalent compound between element Z and Y.
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X23
11 Y35
17 Z12
6
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Electron arrangement of atom Z is 2.4
Electron arrangement of atom Y is 2.8.7
Atom Z needs 4 electrons, while atom Y needs 1 electron to
achieve the stable electron arrangement.
Thus, one atom of Z shares 4 pairs of electron with 4 atoms of Y
forming a molecule of covalent compound with the formula ZY4
PAPER 3
3. Diagram 2 shows the set-up of apparatus for an experiment to compare thereactivity of alkali metal towards their reaction with oxygen.
Rajah 1 menunjukkan susunan radas bagi satu eksperimen untuk membandingkan
kereaktifan logam alkali terhadap oksigen.
Diagram 2
The experiment is carried out using a small piece of lithium, potassium and sodium
respectively to react with oxygen gas.
Observation on the alkali metals in the experiment are given in Table 2.Eksperimen dijalankan dengan menggunakan kepingan kecil litium, kalium and
natrium untuk bertindak balas dengan gas oksigen.
Pemerhatian ke atas logam-logam alkali dalam eksperimen ditunjukkan dalam
Jadual 2.
Set Type of alkali metals
Jenis logam alkali
Observations
Pemerhatian
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Gas jar
Oxygen gas
Alkali metal
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I Lithium Lithium burns slowly and produces white
fume.
Litium terbakar dengan perlahan danmenghasilkan wasap putih.
II Sodium Sodium burns rapidly and produce white
fume.
Natrium terbakar dengan cepat dan
menghasilkan wasap putih.
III Potassium Potassium burns very rapidly and produce
white fume.
Kalium terbakar dengan sangat cepat danmenghasilkan wasap putih.
Table 2
a) State one hypothesis for the experiment.
Nyatakan satu hipotesis bagi eksperimen itu.
The reactivity of alkali metals increases when going down Group 1.
[3 marks]b) Based on the experiment, complete the table below.
Berdasarkan eksperimen tersebut, lengkapkan jadual di bawah.
Manipulated Variable:
Pembolehubahdimanipulasikan:
Type of alkali metals
Method to manipulate the variable:
Kaedah memanipulasikan pembolehubah:
Use different type of alkali metals.
Responding variable:
Pembolehubah bergerak balas:
Reactivity of alkali metals
What to observe in the responding
variable:Apakah yang diperhatikan dalam
pembolehubah bergerak balas:
Observe the burning of alkali metals
when react with oxygen.
Fixed variable:
Pembolehubah dimalarkan:
Oxygen gas// size of alkali
metals
Method to maintain the fixed variable:
Kaedah menetapkan pembolehubahdimalarkan:
Use oxygen gas in each experiment // Use
the same size of alkali metals
[6 marks]
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c) Based on the observations in Table 2, arrange lithium, potassium and sodium indescending order of reactivity towards oxygen.
Berdasarkan pemerhatian dalam Jadual 2, susunkan litium, kalium dan
natrium mengikut tertib kereaktifan logam terhadap oksigen secara menurun.
Potassium , sodium , lithium.
[3 marks]
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OBJECTIVE QUESTION
1 D
2 C
3 D
4 D
5 B
PAPER 2
1. Figure 1 shows a set of apparatus used to electrolyse molten potassium bromide,KBr using carbon electrodes.
Gambarajah menunjukkan radas yang digunakan bagi mengelektrolisiskan kalium
bromida, KBr menggunakan elektrod karbon.
Figure 1
a. Draw an arrow to show the direction of electron flow in the diagram.Lukis anak panah untuk menunjukkan arah pergerakan elektron pada rajah
tersebut. [1 mark]
b. Write the formula of ions present in the electrolyte.
Tuliskan formula ion yang hadir dalam elektrolit.
Pb2+, Br-,
[1 mark]
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MODULE 3MODULE 3
Elektrolit leburan plumbum
(II) bromida
Mangkuk pijar
Panaskan
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Elektrod karbon
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c. Identify the electrode that act as anode and cathode.Kenalpasti elektrod yang bertindak sebagai anod dan katod.
i. Electrode X : Anode
ii. Electrode Y : Cathode[ 2 mark]
d. Diagram 2 below shows electrolyse cell.
Rajah 2 di bawah menunjukkan sel elektrolisis
Diagram 2
Rajah 2
i) Write the formula of all the ions present in the copper (II) sulphate solution. Tuliskan formula semua ion yang hadir dalam larutan kuprum (II) sulfat.
Cu 2+, SO42-, H+, OH -
[1mark]
ii) Name the ions attacted to :
Namakan ion yang tertarik ke:
a) Anode: hydroxide ion
b) Cathode: copper ion[2mark]
iii) State the energy conversion occur in the cell.
Nyatakan perubahan tenaga yang berlaku dalam sel.
Electrical energy to chemical energy
[1mark]
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Copper(II)sulphate
solution
Carbon
electrode
Larutan kuprum (II) sulfat
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2.
a) State the energy conversion occur in voltaic cell .Nyatakan perubahan tenaga yang berlaku dalam sel kimia.
Chemical Energy to Electrical energy
[ 1 mark ]
b) List the ions contain in the electrolyte.
Senaraikan ion-ion yang terkandung di dalam elektrolit.
Na+, NO3-, H+, OH-
[ 1 mark ]
c) Give one device which can be used to replace the function of voltmeter.
Berikan satu alat yang boleh digunakan untuk menggantikan fungsi voltmeter.
Bulb/ Galvanometer
[ 1 mark ]
d) State 2 differences of voltaic cell compared to electrolysis cell. Nyatakan 2 perbezaan sel kimia berbanding sel elektrolisis.
-Energy conversion (chemical energy to electrical energy in voltaic cell and
vice versa)
-Cell structure (voltaic cell do not need a dry cell while electrolysis cell need)
[ 2 mark ]
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Kuprum
Larutan natrium nitrat
Logam lain
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PAPER 3
Answerall question.
1. Figure 1 shows an experiment to construct an electrochemical series by measuring thevoltage of a pair of metals in a simple voltaic cell
Rajah 1 menunjukkan satu eksperimen untuk membentuk satu siri elektrokimia
dengan cara mengukur nilai voltan pasangan logam dalam satu sel kimia.
Figure 1/Rajah 1
Figure 2/Rajah 2
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Logam lain
Larutan natrium nitrat
Kuprum
ee
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Figure 2 shows the reading on the volmeter in different sets of experiment
Rajah 2 menunjukan bacaan voltmeter dalam set eksperimen yang berbeza
(a) Write the voltage for each experiment in the spaces provided in the table below
Tuliskan nilai voltan untuk setiap eksperimen di dalam jadual yang diberikan
ExperimentEksperimen Positive terminalTerminal positif Negative terminalTerminal negatif Voltage/VVoltan/V
1 Copper
Kuprum
Magnesium
Magnesium2.5
2 Copper
Kuprum
Iron
Ferum0.8
3 Copper
Kuprum
Lead
Plumbum0.4
4 Copper
Kuprum
Zinc
Zinc1.1
(b) Show the direction of electron flow on figure 1.
Tunjukkan arah pergerakan elektron pada gambarajah 1.
[3 marks]
(c) What is the function of voltmeter in voltaic cell.
Apakah fungsi voltmeter di dalam sel kimia.
To measure the reading of voltage[3 marks]
(d) Arrange the metals in (a) in the electrochemical series in ascending order.
Susun logam dalam soalan (a) dalam siri elektrokimia mengikut tertib menaik.
Mg, Zn, Fe, Pb, Cu[3 marks]
(d) Explain why copper be a positive terminal compare to its metal pair base on the
arrangement of metal in electrochemical series.
Jelaskan mengapa kuprum bertindak sebagai terminat positif berbanding pasangan
logamnya berpandukan kepada aspek susunan logam di dalam siri elektrokimia.
Because is place lowest compared to other metals in electrochemical series/
Copper is less electropositive metal[3 marks]
(e) Another voltaic cell is formed by using magnesium and iron as electrodes. Which
electrode will be the positive terminal?
Satu sel kimia yang lain dibina dengan menggunakan magnesium dan ferum sebagai
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elektrod.Elektrod yang manakah akan bertindak sebagai terminal positif?
Iron[3 marks]
PAPER 2
PAPER 3
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Objective Question
1 B2 A
3 C4 A5 B
Question Answer
1 (a) 2NH3 (g) + 3H2 (g)
2NH3 (g)
(b)(i)
Ammonium nitrate
Ammonium sulphate
(b) (ii)NH4NO3NH4SO4
MODULE 4MODULE 4
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Question Answer
1 (a)
Experiment I : 1.1 V
Experiment II : 2.7 VExperiment III : 2.0 V
Experiment IV : 0.8 V
Experiment V : 0.5 V( score 3: all corrects value includes units )
(b)
Experiment Negative terminal Voltmeter reading (V)
Experiment I P 1.1
Experiment II Q 2.7
Experiment III R 2.0
Experiment IV S 0.8
Experiment V T 0.5
(c)
(i) metal at negative terminal / two different metals / pairs of two
different metals.. (any one )
(ii) voltmeter readings / potential differences ( any one )
( iii ) copper metal / volume and concentration of copper(II) sulphatesolution./ voltmeter ( any one )
( total score : 3 )
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PAPER 3
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Question Answer
(d)
The further the distance between two metals in Electrochemical series,the voltage/ potential difference is higher/larger
or
(e )
(i) The voltage / potential difference in Experiment II is larger than in
Experiment I
or
The voltage / potential difference in Experiment I is lower / smallerthan in Experiment II.
Any one : 3 marks
(ii) Metal Q is more electropositive than metal P
The distance of metal P is nearer to copper compared to metal Q
in Electrochemical series.
The arrangement is Q, P and copper in the Electrochemicalseries in descending order.
3 marks
(f) Q , R, P , S , T , Cu3 marks
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AnswerProblem Statement Are alloy is harder than pure metals
All variables
- Manipulated Variable : Different types of materials
( aluminium and duralumin )
-Responding Variable : Diameter of dent
- Constant Variable : Diameter of steel ball bearing,Height of the weight,
mass of the weight.
Hypothesis
Alloy is harder than pure metal /
Duralumin is harder than aluminium
List of materials
and apparatus
Materials : aluminium block, duralumin block and
cellophane tape.
Apparatus : retort stand and clamp, one kilogram weight, steel ball
bearing, metre rule and thread.
Procedure
1. A cellophane tape is used to to stick a steel ball bearing onto the
aluminium block.
2. A weight is hung above the ball bearing at a height of 50 cm.3. The weight is dropped so that it hits the ball bearing.
4. The diameter of the dent made on the aluminium block is
measured.
5. Steps 1 to 4 is repeated twice.6. By replacing aluminium block with the duralumin block, steps 1 to
5 is repeated.
7. The readings are recorded in the table below.
Tabulation of data
Type of block /
material
Diameter of dents
( cm )
Average diameter
(cm )
1 2 3Duralumin
Aluminium
MODUL 5MODUL 5
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Question Answer
1 (a) 2HCl + CaCO3 CaCl2 + CO2 + H2O
(b) Rate of reaction = 32 / 50 = 0.64 g/cm3
(c) (i)
(c)(ii)
1- Draw a triangle on the graph - 1 mark
2- Rate of reaction = 18 / 77.5 - 1 mark
= 0.23 cm3 / s
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3.
(a)
1. antibiotic2. This is to make sure that all the bacteria are killed.
3. Otherwise, patient B may become ill again
4. bacteria may become more resistant to the antibiotic.5. As a result, the antibiotic is no longer effective.
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Question Answer
2 (a)Heat of displacement is the heat change when one mole of a metal isdisplaced from its salt solution by a more electropositive metal.
(b)
The intensity of blue solution ( copper(ll) sulphate solution ) in this
reaction decreases until they become colourless.
(c) Zn + Cu 2+ Zn 2+ + Cu
(d)
(i) Number of mole of copper(ll) ions= MV1000
= 2(25)
1000= 0.005 mole.
(ii) mc = 25 x 4.2 x 9.5 = 997.5 joule
(iii) The heat of displacement of copper by zinc
997.5
= ----------0.005
= 199500 J
= 199.5 kJ/mol
(e)
Energy
Zn + Cu 2+
H = -199. 5 kJ/mol
Zn 2+ + Cu
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(b)
A: Hydrophobic part
B: Hydrophilic partPart A is dissolved in oil / grease
Part B is dissolved in water
(c) (i)
Procedure:1. Two basins/beakers are filled with hard water.2. Soap is added to one beaker and detergent is added to another beaker.
3. A piece of dirty cloth is placed into each beaker and agitated.
4. Observations:
Soap in hard water Detergent in hard water
1. cloth not clean
2. scum forms
3 water less dirty
1. cloth clean
2. no scum
3. water turns dirty
(any one pair)
5. Conclusion: detergent cleans stains more effectively than soap.
(c) (ii):
1. soap particles dissolve in water and (reduce the surface tension of water)/(water wet the cloth thoroughly)
2. the hydrophilic part dissolve in water while the hydrophobic part dissolves in
grease//diagram3. During cleaning/rubbing/heating/scrubbing, grease is lifted off the surface
4. Hydrophobic part / soap anion surrounded the grease//diagram
5. Grease is broken up into small droplets/forming an emulsion//diagram
6. When rinsed, the grease droplet will be removed
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