Name : _____________________ ( ) Class :_______
MID-YEAR EXAMINATION 2009
SECONDARY 2 EXPRESS
LOWER SECONDARY SCIENCE
Date : 15 May 2009 Day : Friday
Duration : 1 hour 30 minutes Mark : 80 marks
INSTRUCTIONS TO CANDIDATESADDITIONAL MATERIALS
1 OTAS2 Writing papers1 Graph Paper
INSTRUCTIONS TO CANDIDATESWrite your name, class and register number in the spaces provided at the top of this page and on any separate writing paper used.
Section AAnswer all the questions. Shade your answers in the OTAS provided.
Section BAnswer all the questions. Write your answers in the spaces provided.
Section CAnswer all the questions Write your answers in the writing papers provided. Hand in Section C separately
INFORMATION FOR CANDIDATESThe number of marks is given in brackets [ ] at the end of each question or part question.A copy of the Periodic Table is printed on the last page.Approved calculators may be used for this paper.
Name of Setter: Mr Jack TanName of Vetter: Mr Toh Weixiang
__________________________________________________________________________This question paper consists of 15 printed pages, including the cover page.
YISHUN TOWN SECONDARY SCHOOL
Section A (20 marks)Answer all the questions in this section.
1. A compound Y has a melting point of -22ºC and a boiling point of 48 ºC. At which temperature is Y a liquid?
A B C D
-75 -50 -25 0 25 50 75 temperature / oC
2. Which sentence best describes the arrangement of particles in a liquid?
A) They are close together in an orderly arrangement.B) They are close together in a disorderly arrangement.C) They are far apart in an orderly arrangement.D) They are far apart in a disorderly arrangement.
3. How many atoms are there in one molecule of iron (III) nitrate, Fe(NO3)3?
A) 9B) 11C) 13D) 15
4. Which of the following numbers is different for isotopes?
A) Number of protonsB) Number of neutronsC) Number of electrons D) Total number of protons and electrons
5. Which statement about the elements in the Periodic Table is correct?
A) Group 0 elements are unreactive metals.B) Group I elements are reactive non-metals.C) Group VII elements form negative ions.D) The elements become more metallic from left to right across a period.
2
6. The table shows some typical properties of metals and non-metals. Which one of the following set of properties is correct?
Metals Non-metalsA) Good conductor of electricity Usually have a high melting pointB) Usually have a high melting point Good conductor of heatC) Shiny when polished Good conductor of electricityD) Good conductor of electricity Usually dull in appearance
.
7. Which of the following has the most number of electrons?
A) Ca2+
B) S2-
C) NeD) Br-
8. An unknown ion, X2+ contains 23 particles in the nucleus and 10 electrons outside the nucleus. What does the nucleus of the ion X2+ contain?
Protons NeutronsA) 9 14B) 10 13C) 11 12D) 12 11
9. The atom of element X has the electronic configuration 2.8.6. Which statement about element X is correct?
A) X is a poor conductor of electricityB) It forms an ion of charge +2C) It has 2 protons in the outermost shell of an atomD) An atom of X has 12 electrons.
3
10.
Which of the graphs below shows the graph of the number of outer shell electrons against the proton number of the first 12 elements of the Periodic Table?
11.
Which one of the following contains only compounds?
A) Oxygen, water, airB) Nitrogen, neon, chlorineC) Methane, air, sodium chlorideD) Water, carbon dioxide, methane
12.
The diagram below represents the particles in four substances. Which diagram represents a compound?
A B C D
13.
Which of the following statements is true?
A) A mixture of salt and water forms a suspension.B) A solution is a homogeneous mixture where a solute dissolves in a solvent.C) A solution leaves a residue on the filter paper after filtration.D) A saturated solution is one where more solute can be dissolved.
14.
In fizzy drinks, X is the solvent and Y is the solute. Identify X and Y.
X YA) carbon dioxide waterB) water nitrogenC) nitrogen waterD) water Carbon dioxide
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15.
Methylated spirits will remove permanent ink from some surfaces whereas water will not. The best explanation for this is that
A) methylated spirits is stronger than water.B) permanent ink is soluble in methylated spirits.C) permanent ink is soluble in water.D) water will not evaporate as quickly as methylated spirits.
16.
What is the property that allows us to use fractional distillation to separate ethanol from water in alcoholic drinks?
A) They have different melting points. B) They have different boiling points.C) They have different solubilities.D) They have different colours.
17.
Which of the following is suitable to be obtained by crystallisation?
A) Salt from a mixture of sand and saltB) Water from sugar solutionC) Sugar from sugar solution D) Salt from a mixture of salt and sugar
18.
The graph below shows the solubility of oxygen in the temperature range from 0oC – 60oC.
At room temperature (25ºC), what is the maximum mass of oxygen that can dissolve in 200 grams of water?
A) 0.0018gB) 0.0036gC) 0.0072gD) 0.0144g
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19.
The use of a Liebig condenser in distillation is to ________________.
A) convert a liquid to a solidB) convert a liquid to a vapourC) convert a solid to a liquidD) convert a vapour to a liquid
20.
You are given a sample of crystals. What should you check to test the purity of the crystals?
A) Melting pointB) Shape of crystalsC) Size of crystalsD) Solubility
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Section B (30 marks)Answer all the questions in this section.
1. Carbon monoxide has a melting point of -205˚C and a boiling point of -192˚C.
(a) In the space below, draw the particles of carbon monoxide at room temperature.
(b) In a student’s notes, he wrote down that air is a mixture of elements.
(i) Define a mixture.
____________________________________________________________________
____________________________________________________________________
(ii) Hence or otherwise, state whether the student is correct. Explain your answer.
____________________________________________________________________
____________________________________________________________________
(iii) Compare a molecule of an element with a molecule of a compound.
____________________________________________________________________
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(c) Water turns into steam at 100ºC.
(i) Name this change in state.
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(ii) Give two differences between the change in state in (i) and evaporation.
____________________________________________________________________
____________________________________________________________________
[1]
[1]
[2]
[2]
[1]
[2]
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2. (a) Complete the following table.
ElementNucleon Number Protons Neutrons Electrons
Mg 24
64 29 28
Fe3+ 56
Br - 80
31 15 18
(b) In the boxes below, draw the full electronic structure of an atom and ion of nitrogen.
.
(c)
Write down the electronic configuration of the atom and ion of nitrogen.
Atom: _____________________ Ion: _________________________
[5]
[4]
[2]
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Atom Ion
3. The figure below shows a chromatogram obtained by separating the food colouring used in a new type of isotonic drink.
(a) Why does the black spot move further than the white spot?
____________________________________________________________________
(b) Give one precaution when obtaining this chromatogram.
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(b) Calculate the Rf value of the black spot.
(c) Is the colouring pure? Explain your answer.
____________________________________________________________________
____________________________________________________________________
(d) Why should the starting line be drawn in pencil and not ink?
____________________________________________________________________
____________________________________________________________________
(e) Give one advantage of using chromatography to analyse food samples.
____________________________________________________________________
____________________________________________________________________
[1]
[1]
[1]
[1]
[1]
[1]
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4. The diagram below shows the apparatus used to obtain water from sea water.
(a) What is the name of this process?
____________________________________________________________________
(b) What is the purpose of the boiling chips?
____________________________________________________________________
____________________________________________________________________
(c) How do you know the water collected is pure?
____________________________________________________________________
____________________________________________________________________
(d) Label the water in and water out for the condenser.
X: _________________________ Y: ________________________
[1]
[1]
[1]
[1]
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Y
X
Section C (30 marks)
Draw the graph in question 1 on the graph paper provided. Answer all the questions in this section on the writing paper provided. Begin each question on a fresh piece of writing paper.
1. (a) Kate wants to find out the amount of a solute that can dissolve in different volumes of
solvents. The given solvent is water and the solute is sugar. For different amounts of
water, she added sugar till no more sugar can dissolve, and then recorded the mass of
the sugar.
The table below shows the results of her investigation.
Volume of water/ cm3 10 20 30 40 50 60Mass of sugar dissolved/ g 14 32 43 61 76 91
(i) Using the data from the table, plot a graph of mass of sugar dissolved against
volume of water. [4]
(ii) Find the gradient of the graph. [1]
(iii) From the graph, how much sugar can be dissolved in 35 cm3 of water? [1]
(b) Describe, with labelled diagrams, how you would obtain a pure, dry sample of
copper (II) sulphate crystals from a solution of copper (II) sulphate solution. [4]
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2. (a) The graph below shows how the solubility of 4 different substances, vary with
temperature. The solubility of a substance refers to the maximum amount of solute
dissolved in a fixed amount of solvent. In this experiment, all substances were dissolved
in 100 cm3 of water.
(i) Describe the trend between solubility and temperature for the substance P. [1]
(ii) At which temperature does P and R have the same solubility? [1]
(b) At 10ºC, it takes a long time for the different solutes to dissolve.
(i) Describe an experiment to determine how stirring would affect the speed of dissolving. Include in your description the independent variable, the dependent variable and two factors to be kept constant. [4]
(ii) Suggest two other ways beside stirring that result in the solutes dissolving faster. [2]
(c) List two characteristics of a heterogeneous solution. [2]
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3. (a) You are given a mixture containing the following liquids:
Liquid Boiling Point / ˚C
Methanol 64
Ethanol 78
Propanol 98
Butanol 118
(i) Name the most suitable method that can be used to separate the above liquid
mixture into its components. [1]
(ii) Draw a labeled diagram showing how the apparatus can be set up for the method
named in (i). [5]
(iii) Which liquid would be obtained first? Explain your answer. [2]
(b) An unknown substance is a liquid at room temperature but quickly solidified in a
refrigerator. Describe two ways to determine if the liquid is a pure substance. [2]
~ End of Paper ~
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DATA SHEETThe Periodic Table of the Elements
Group
I II III IV V VI VII 0
1
HHydrogen
1
4
HeHelium
2
7
LiLithium
3
9
BeBeryllium
4
11
BBoron
5
12
CCarbon
6
14
NNitrogen
7
16
OOxygen
8
19
FFluorine
9
20
NeNeon
10
23
NaSodium
11
24
MgMagnesium
12
27
AlAluminium
13
28
SiSilicon
14
31
PPhosphorus
15
32
SSulphur
16
35.5
ClChlorine
17
40
ArArgon
18
39
KPotassium
19
40
CaCalcium
20
45
ScScandium
21
48
TiTitanium
22
51
VVanadium
23
52
CrChromium
24
55
MnManganese25
56
FeIron
26
59
CoCobalt
27
59
NiNickel
28
64
CuCopper
29
65
ZnZinc
30
70
GaGallium
31
73
GeGermanium
32
75
AsArsenic
33
79
SeSelenium
34
80
BrBromine
35
84
KrKrypton
36
85
RbRubidium
37
88
SrStrontium
38
89
YYttrium
39
91
ZrZirconium
40
93
NbNiobium
41
96
MoMolybdenum
42
TcTechnetium
43
101
RuRuthenium
44
103
RhRhodium
45
106
PdPalladium
46
108
AgSilver
47
112
CdCadmium
48
115
InIndium
49
119
SnTin
50
122
SbAntimony
51
128
TeTellurium
52
127
IIodine
53
131
XeXenon
54
133
CsCaesium
55
137
BaBarium
56
139
LaLanthanum
57 *
178
HfHafnium
72
181
TaTantalum
73
184
WTungsten
74
186
ReRhenium
75
190
OsOsmium
76
192
IrIridium
77
195
PtPlatinum
78
197
AuGold
79
201
HgMercury
80
204
TlThallium
81
207
PbLead
82
209
BiBismuth
83
PoPolonium
84
AtAstatine
85
RnRadon
86
FrFrancium
87
226
RaRadium
88
227
AcActinium
89
*58-71 Lanthanoid series90-103 Actinoid Series
a = relative atomic massKey x = atomic symbol b = proton (atomic) number
140
CeCerium
58
141
PrPraseodymium59
144
NdNeodymium
60
PmPromethium
60
150
SmSamarium
62
152
EuEuropium
63
157
GdGadolinium
64
159
TbTerbium
65
162
DyDysprosium
66
165
HoHolmium
67
167
ErErbium
68
169
TmThulium
69
173
YbYtterbium
70
175
LuLutetium
71
232
ThThorium
90
PaProtactinium
91
238
UUranium
92
NpNeptunium
93
PuPlutonium
94
AmAmericium
95
CmCurium
96
BkBerkelium
97
CfCalifornium
98
EsEinsteinium
99
FmFermium
100
MdMendelevium
101
NoNobelium
102
LrLawrencium
103
The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.)
a
X
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