Stpm Trial 2009 Che Q&a (n9)
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View Stpm Trial 2009 Che Q&a (n9) as PDF for free.
More details
- Words: 7,257
- Pages: 40
papercollection
96211 IN(;KAJAN FN/LH DALHAfi S/:,RLHHAN PAN! rtA T!i\f;'/<",·i 1A \ IYtt..l Chemistry IRJ:,\4HAlV f~:\'\If!:l T1;V(i/
1-4 hours
r'/?,'t{l SFRFAllf:\N 1).:\;\'11'//\ TlNGl<:'\ [:iN 'I,ve ',',\,':~l i'VI IJ:if:.R .'~\ fI;! '"~'f'"'.[\Dj'tt l'); \' i '''/ r',!1. I;' " ,II';' f,; ~i ),'"
r:N:IA.f f),,\ER.iif SFI?FJ1IUN 'f'f'\'( .,' ,F',:V'''' h' , ';.1 i'.''J/ \/ \ '(', li\'"
f)':,f 1 .\:''/'j / ''\
,;ERF;UH'\;\ P(\r\ITf/\ Tf/\'(/!{frT'1iV FNk'd f)/';FR:Hf SF;r?F'tflU/v I'AN1J1A n.NGK,:HAN j JABATAN PELAJARAN NEGERI {jZ'l'ffl.,lERAIl SL,REJ{B:\N p:, NEGERI SEMBILAN DARUL KHUSUS '\ 11:\G/\/\1:\:\' F!YAM UALR/ if ," rel="nofollow">LRFM1J:\,\J
_
, "c."",
PEPERIKSAAN PERCUBAAN \J\fAA LVAM :),';~::?~ll: ,:/,:,1<: SIllL TINGGI PERSEKOLAHAN MALAYSIA ?~AiV l)ANf;nA j'ANIT1A
nN(
n"(II..:\ lAd
"Lit U1Uv\/f
j
S1~.Rl';''\4HA!V p; I'.-'!YAM
2009
fJ4LRAIf
.'·;FREMrI4;V PANlTfA
nW,'KAf/\!V Fi\'Aiti
A 11\(/I
lJAJ:,'/?:l.f/
,<;rRr:MH.V";
DO NOT OPEN THIS BOOKLET UNTIL YOU ARE TOLD TO DO SO Instructions to candidates: There are fifty questions in this paper. For each question, four suggested answers are given. Choose one correct answer and indicate it on the multi-choice answer sheet provided. Read the instructions on the multiple-choice answer sheet very carefully, Answer all questions. Marks will not be deducted for wrong answers. A Data Booklet is provided.
This question paper consists of 18 printed pages [Turn Over
96211 © Sept
2008
Copyright PPD Seremban
papercollection
Confidential*
2 Section A
Four suggested answers labelled A, B, C, and D are given for each question. Choose one correct answer.
1
A manometer is a device for measuring gas pressures. A sample of nitrogen gas is placed in a close-end manometer at 25°C until there is an increase of 0.100 g in its mass. The diagram below shows the height of mercury in the manometer.
What is the volume of the nitrogen gas in the manometer? [Relative atomic mass: N=14.0; molar gas constant = 8.31 J K–1 mol–1; 760 mm Hg = 101 kPa]
2
A
95 cm3
B
111 cm3
C
133 cm3
D
266 cm3
Which of the following statements is true of the hydrogen line spectrum? A
The number of lines in each series is the same.
B
The first line in each series has the lowest frequency.
C
The lines in a series become closer when the frequency decreases.
D
The ionisation energy of hydrogen can be calculated from the frequency of the first line of the Lyman series.
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential* 3
3
The phase diagram for iodine is shown below.
Which of the following statements is true?
4
A
Point C is the critical temperature.
B
At point B, solid iodine and liquid iodine exist in equilibrium.
C
The line OC represents the effect of pressure on the melting point of iodine.
D
Iodine sublimes when heated from room temperature to 120 °C at a constant pressure of 14 kPa.
The following graph shows the variation of a physical property of Period 3 elements (sodium to argon) in the Periodic Table.
A
Enthalpy of vaporisation
B
Electrical conductivity
C D
First ionisation energy Electronegativity
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential* 5
4
The elements X and Y have the following electronic configuration. X : 1s2 2s2 2p6 3s2 Y : 1s2 2s2 2px2 2py2 2pz2 When X reacts with Y, what is the formula of the compound and the most likely type of bond formed?
6
7
8
Formula
Type of bond
A B C
X2Y2 XY2 X2Y
Ionic Ionic Covalent
D
X2Y3
Covalent
Which of the following substances has the strongest intermolecular force in its liquids state? A
NH3
B
CH4
C D
C2H5OH CO2
Which of the following species does not involve the formation of dative bonds? A
SO42-
B
NH4+
C
NO3-
D
[ Cu (NH3)4 ] 2+
The synthesis of ammonia from hydrogen and nitrogen is an exothermic reaction. Which of the following will increase both the rate of the forward reaction and the yield of ammonia ? A
Decreasing the pressure
B
Increasing the pressure
C
Increasing the temperature
D
Increasing the quantity of catalyst used
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential* 9
5
The energy diagram for three substances P,Q and R are shown below. P Q R
Valence band
Valence band Valence band
Which of the following combination is correct?
A B C
P conductor semi-conductor conductor
Q non-conductor non-conductor semi-conductor
R semi-conductor conductor non-conductor
D
non-conductor
semi-conductor
semi-conductor
The equilibrium constant, Kc , for these reaction
10
2NH3 (g) + 3CuO (s) A
[Cu] 3 [N2] [H2O]3 [NH3] 2 [CuO] 3
B
[N2] [H2O]3 [NH3]2
C
[N2] [H2O]3 [NH3]
D
3[N2] [H2O] 2[ NH3]
3Cu(s) + N2 (g) + 3H2O (g)
11 What is the pH of the solution formed when 50.0 cm3 of 0.10 mol dm-3 aqueous ammonia is mixed with 20.0 cm3 of 0.05 mol dm-3 aqueous ammonium chloride ? [pKb for ammonia = 4.75] A
10.3
B
9.95
C D
8.12 7.61
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
6
12 50 cm3 of aqueous silver nitrate (V) is added to 50 cm3 of 0.20 moldm-3 aqueous sodium chloride. What is the minimum concentration of silver nitrate (V) solution in moldm-3 needed to precipitate silver chloride? [ Ksp of AgCl = 2.0 x 10-10 mol2 dm-6 ] A
1.0 x 10-9
B
4.0 x 10-9
C
2.0 x 10-10
D
2.0 x 10-11
13 A solution of 5.0 g of an organic compound Q in 50 cm3 of water was shaken with 100 cm3 of ether. After separation, the aqueous solution was found to contain 0.98 g of Q. What is the partition coefficient of Q between ether and water? A B C
6.250 2.625 2.050
D
1.825
14 The diagram shows the boiling point-composition of a mixture of two liquids P and Q. Temperature
Z
1.0 Xp What is the composition of the distillate if a mixture of composition Z is fractionally distilled? 0
A B C
Pure P Azeotropic mixture Pure P and azeotropic mixture
D
Pure Q and azeotropic mixture
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential*
7
15 An electrochemical cell is prepared by using a copper electrode immersed in an aqueous solution of copper(II) sulphate solution and a platinum electode immersed in an aqueous solution of potassium chlorate(I). The standard electrode potentials of the two half-cells are as follows Cu Cu2+ + 2eClO + H2O + 2e
Cl- + 2OH-
Eθ = +0.34 V Eθ = +0.89 V
Which of the following statements is not true for the above cell? A
The e.m.f of the cell is 0.55 V
B
The copper electrode is the anode
C
The chlorate(I) ion acts as an oxidising agent
D
Electrons flow from the platinum electrode to the copper electrode
16 A steady current flows through an aqueous solution of potassium iodide for 4825 seconds. The iodine produced requires 12.5 cm3 of 0.80 mol dm-3 sodium thiosulphate(VI) for complete reaction. What is the value of the current flowing in this electrolytic cell? [ I2 ≡ 2S2O32- ; 1F = 96, 500 C mol-1] A
0.1 A
B
0.2 A
C
0.3 A
D
0.4 A
17 A certain quantity of electricity produces 2.94 g of copper when an aqueous solution of copper(II) sulphate solution is electrolysed. When the same amount of charge is passed through an aqueous solution containing the Xn+ ions, 6.0 g of X is produced. What is the value of n? [ Cu = 63.5; X = 197 ] A
1
B
2
C
3
D
4
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
8
18 Which of the following processes involves the enthalpy change of formation? A
H2(g) + O2(g) H2O2(l)
B
CO(g) + ½ O2(g)
C
2N(g) + 3H2(g) 2NH3(g)
D
Mg(s) + C(s) + 3O2(g)
CO2(g) MgCO3(s)
19 Consider the following neutralisation reactions below:NaOH(aq) + HCl(aq) NaCl(aq) + H2O(l) NaOH(aq) + ½ H2SO4(aq) ½ Na2SO4(aq) + H2O(l)
∆H1 = -57.3 kJ ∆H2 = -66.5 kJ
∆H2 is more negative than ∆H1 because:A
H2SO4 is a stronger acid than HCl
B
the lattice energy of HCl is higher than that of H2SO4
C
the heat of dilution of H2SO4 is much larger than that of HCl
D
H2SO4 dissociates completely in water while HCl only dissociates partially.
20 Which of the following electronic configuration of elements is most likely to react with steam than water? A
1s22s22p63s1
B
1s22s22p63s2
C
1s22s22p63s23p1
D
1s22s22p63s23p2
21 Which one of the following reactions is characteristic of aluminium hyroxide? A
It reacts with sulphuric acid to give a white precipitate of aluminium sulphate.
B
It fumes in the presence of hydrochloric acid because volatile aluminium chloride is formed. It dissolves in aqueous sodium hydroxide to give a solution of sodium aluminate. It reacts with aqueous sodium hydroxide to give a white precipitate of sodium aluminate.
C D
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential*
9
22 Silicon (IV) oxide is a solid whereas carbon (IV) oxide is a gas. This is because A
carbon is more electronegative than silicon
B
the silicon-oxygen bond is stronger than the carbon-oxygen bond
C
silicon(IV) oxide partially ionic whereas carbon(IV) oxide is purely covalent
D
silicon (IV) oxide is a giant molecule whereas carbon (IV) oxide is a simple molecule.
23 When CO2 gas is passed through limewater, a white precipitate of CaCO3 is formed. If an excess of CO2 is passed through, the white precipitate dissolves because
C
as more and more CO2 gas dissolves, the solution becomes increasingly acidic, hence CaCO3 changes to CaHCO3 which is soluble. as more and more CO2 gas dissolves, the solution becomes increasingly acidic and CaCO3 will decompose as more and more CO2 gas dissolves, a soluble complex is formed.
D
the precipitate CaCO3 will react with an excess of CO2 to form CaO
A B
24 In the Haber process, nitrogen gas is obtained from A
reduction of nitrogen dioxide
B
fractional distillation of liquefied air
C
catalytic decomposition of hydrazine
D
thermal decomposition of ammonium salts
25 Chlorine gas is bubbled through aqueous sodium hydroxide.What is the use of the solution obtained? A
Deodorant
B
Antiseptic
C
Bleaching agent
D
Aerosol propellant
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
10
26 In which of the following compounds is the transition metal having the highest oxidation state? A
K2CrO4
B
MnC2O4
C
NH4VO3
D
K4Fe(CN)6
27 Nickel is used as a catalyst in the hydrogenation of unsaturated fatty acids to saturated fatty acid in the manufacture of margarine. How does nickel help in the reaction? A
Nickel does not react with the products
B
Nickel shows variable oxidation number
C
Nickel has available d orbitals for bonding
D
Nickel forms a stable intermediate with the reactants
28 1,3-butadiene, is used to synthesis SBR rubber. How many pi (п) and sigma (σ) bonds are present in one molecule of 1,3-butadiene? Number of pi (п) bonds
Number of sigma (σ) bonds
A
1
7
B
1
9
C
2
7
D
2
9
29 From the dibromination of propane , four isomeric products with the formula C3H6Br2, were isolated. . However, only one of the products, S, shows optical activity. What is the structural formula of S? A
1,1-dibromopropane
B
1,2-dibromopropane
C
1,3-dibromopropane
D
2,2-dibromopropane
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential*
11
30 Which one of the following is correct about 1-butene and 2-butene? A
Exhibits cis-trans (geometrical) isomerism
B
Reacts with bomine to give 1,4-dibromobutane
C
Oxidized by hot acidified potassium manganate(VII) to diols.
D
Reacts with hydrogen in the present of Nickel to form butane
31 Which property of benzene may be directly attributed to the stability associated with its delocalized electrons? A
It tends to undergo substitution rather than addition reactions
B
It is susceptible to attack by nucleophilic reagents
C
Its enthalpy change of formation is positive
D
It does not conduct electricity
32 An organic halogen compound X was boiled with aqueous sodium hydroxide. When aqueous silver nitrate solution was then added to the mixture, little or no precipitate was obtained. Which of the following formulae could represent compound X? A
CH3CH2CHCH2CH3
C —CH2Cl
Cl B
CH3CH2CH2COCl
D
—Cl CH3
33 An organic compound L gives a yellow precipitate when heated with a solution of iodine in sodium hydroxide. Which of the following compounds could be L? A
CH3CH2CH2CH(OH)CH3
B
(CH3)2CHCOCH(CH3)2
C
(CH3)2C(OH)CH2CH3
D
CH3CH2COCH2CH3
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
12
34 An organic compound M has the following properties:• • •
optically active. reacts with 2,4 dinitrophenylhydrazine to give an orange precipitate releases hydrogen chloride gas when reacted with phosphorus pentachloride.
The structural formula of M is A HOCH 2— HOCH2CH 2CH 2—
—C—CH —C—CH33 ║║ OO
HOCH2—
—C—CH2CH3 ║ O
B
C HO—
—C—CH—CH3 ║ │ O CH3
D —C—CH—CH —C—CH—CH22OH OH ║║ ││ O O CH CH33 35 The best method to prepare phenyl benzoate is by A
mixing benzoyl chloride with phenol dissolved in aqueous sodium hydroxide
B
mixing benzoyl chloride with phenylmethanol.
C
refluxing benzoic acid with phenylmethanol.
D
refluxing benzoic acid with phenol.
36 What is the compound formed when dimethylamine, (CH3)2NH is reacted with nitrous acid? A
(CH3)2N – N = O
B
CH3CH2OH
C D
(CH3)2NOH (CH3)2N = N+
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential*
13
37 The following reaction scheme shows how propanone is changed to an ester. I CH3COCH3
II Y
C6H5COOCH(CH3)2
What are the reagent I and II in the above scheme? I
II
A
LiAlH4
C6H5OH
B
LiAlH4
C6H5COCl
C
NH3
C6H5CH2CI
D
H2
C6H5CH2COOH
38 Dopamine is a drug used in the treatment of Parkinson’s disease. HO HO
OH OH NH NH2 2 CH CH22CH CH CO CO2H 2H
Which one of the following statements about this compound is incorrect? A
It can be use to produce esters
B
It can exist in optically active forms
C D
It can exist as a zwitterion in aqueous solution One mole will react with one mole of sodium hydroxide to form a salt
39 Which of the following will react with 1,2-ethanediol to form a polymer? A
HOOCC6H4COOH
B
HOOC(CH2)4OH
C D
HOC6H4COOH C6H5COOH
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
14
40 The synthetic rubber, SBR is prepared by the reaction between:A
CH2=CH—CH=CH2
B
CH2=C—CH=CH2 │ CH3
and
and
CH=CH2 │
CH=CH2 │
C
CH2=CH—CH=CH2 and CH2=C—CH=CH2 │ CH3
D
CH2=C—CH=CH2 │ Cl
and CH2=CH—CH=CH2
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential*
15 Section B
For each of the questions in this section one or more of the three numbered statements 1 to 3 may be correct. Decide whether each of the statements is or is not correct. The responses A to D should be selected on the basis of the following. A 1 only is correct.
B 1 and 2 only are correct.
C 2 and 3 only are correct.
D 1, 2, and 3 are correct.
41 The mass spectrum of an element X is shown below.
1
Element X consists of two isotopes with relative isotopic mass of 14 and 15
2
The isotopes of X have a different number of protons
3
The nucleon number of X is 14.5
42 Which of the following statement(s) is/are true about the elements in Group 2 of the Periodic Table? 1
They are reducing agents
2
The ionic radius increases down the group
3
The electronegativity increases down the group
43 Which of the following statement(s) about methane, ammonia and water is/are correct? 1
The bond angle in methane is larger than the bond angle in ammonia
2
The C-H bond in methane is longer than the O-H bond in water
3
The bond angle in ammonia is larger than the bond in water
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
16
A 1 only is correct.
B 1 and 2 only are correct.
C 2 and 3 only are correct.
D 1, 2, and 3 are correct.
44 Ethanoic acid is a weak acid and hydrochloric acid is a strong acid . It follows that the 1 2 3
solution containing 0.100 mol dm-3 ethanoic acid and 0.100 mol dm-3 sodium ethanoate will be a good buffer solution formed by mixing equal number of moles of sodium hydroxide and ethanoic acid will have a pH of more than 7 pH of 0.100 mol dm-3 hydrochloric acid will be less than that of 0.100 mol dm-3 ethanoic acid.
45 Consider the following reaction 2MO3- + SO32- + 6H+ 2MO2+ + SO42- + 3 H2O It can be concluded that 1
the conversion of MO3- to MO2+ involves the transfer of 1 mol of electrons
2
the MO3- ion acts as an oxidising agent
3
the H+ ion is reduced to H2O
46 The Group 14 element germanium is widely used in the manufacture of semiconductors and other electronic components. The existence of this element in Group 14 between silicon and tin was predicted by Mendeleev some years before it was discovered. From its position in the group, what properties of germanium may be predicted? 1
GeCl4 is volatile liquid at room temperature.
2
Its most stable oxide has the formula GeO2
3
The oxides GeO2 forms ions GeO32-
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential*
17
A 1 only is correct.
B 1 and 2 only are correct.
C 2 and 3 only are correct.
D 1, 2, and 3 are correct.
47 Which of the following statement(s) regarding the hydrogen halide is/are true? 1
All are gas at room condition
2
The acidic strength increases in the order HCl < HBr < HI
3
The strength of the H-X bond increases in the order HI < HBr < HCl
48 Which of the following statements suggest the presence of free radicals in the chlorination of methane? 1
Hydrogen chloride is the major product
2
Ethane is present in small quantities in the product
3
The reaction proceeds most quickly in sunlight or ultraviolet light
49 Which of the following pairs of compounds will react together followed by hydrolysis, to form a compound with the structure below? CH3 │ CH3CH2 —C—OH │
1 —MgBr with
CH3COCH2CH3
2 —C—CH3 with CH3CH2MgBr ║ O 3 —C—CH3 with ║ O
CH3MgBr.
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
A 1 only is correct.
18
B 1 and 2 only are correct.
C 2 and 3 only are correct.
D 1, 2, and 3 are correct.
50 Which of the following compounds can react with excess acidified potassium manganate(VII) solution and the product formed liberate a gas that turns lime water chalky with sodium carbonate? 1
CH3CH(CH3)OH
2
CH3CH2CH2OH
3
CH3CH(CH3)CHO
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
CONFIDENTIAL *
<:Iass: ....................................... .
N arne: ...................................... .
:GERISEMBILAN JA lAB/LAN JABATAfI :GERISEMBILAN JA ItBILAN JABATA/\ :GERISEMBILAN JA JABATAfI IABILAN JABATAI\ . ..... ~ WI .. " .. w. w .....:GERISEMBILAN JALJI ,. I .... ..... ~ 'VI " " " •• w..... """ ...... ",-, ...... AB/LAN JABATANPELAJARANNEGERISEMBILAN JABATANPELAJARANNEGERISEMBILAN JABA TANPELAJARANNEGERISEMBILAN JABATANPELAJARANNEGERISEMBILAN JABA TANPELAJARANNEGER/SEMBILAN JABA TANPELAJARANNEGERISEMB/LAN JABATANPELAJARANNEGER/SEMBILAN JABATANPELAJARANNEGERISEMBILAN JABATANPELAJARANf'v AJARANNEGERISEMB/LAN JABATANPELAJARANN AJARANNEGERISEMBILAN JABATANPELAJARANf'v ___ . " __ "'_'_" __ .. _ ...... _. _-AJARANNEGERISEMBILAN JABATANPEL A.IARANNFr,FRISFMRII AN .IARATANPFI A.IARANNEGERISEMBILAN JABATANPEL Paper 2 EGERISEMBILAN JABATANPEL EGER/SEMB/LAN JABA TANPELMvl'1rv1IVIVc0cnluCIVIDtLMIV vI'1Dl'1ll'1tVrCLMvl'1rv1IVlvEGER/SEMBILAN JABA TANPELAJARANNEGERI,"""'· ..... ANPELAJARANNEGERISEMB/LAN JABATANPELAJARANNEGERf. (2 ~ hours) -ANPELAJARANNEGERISEMBILAN ~NPELAJARANNEGERISEMBILAN JABA TA NPELA JA RA NNEGERI, JABA TANPELAJARANNEGER/ JABA TANPELAJARANNEGERISEMB/LAN
962/2
STPM 2009
CHEMISTRY
II
•••
• . . . . . . "T"
JABATAN PELAJARAN NEGERl SEMBILAN PERCUBAAN BERSAMA SIJIL TINGGI PERSEKOLAHAN MALAYSIA
2009 Instructions to candidates:
For examiner's use
1 DO NOT OPEN TIDS QUESTION PAPER UNTIL YOU ARE TOLD TO DO SO.
2
3 Answer all questions in Section A. Write your answers in the spaces provided
4 5
Answer any four questions in Section B. Write your answers on your own test pad Begin each answer on a fresh sheet ofpaper. Answers should be illustrated by large and clearly labeled diagrams wherever suitable.
6 7
8
Arrange your answers in numerical order and tie the answer sheets to this question paper.
9 10 Total
This question paper consists of 11 printed pages STPM TRIAL 96212
CONFIDENTIAL *
papercollection
Section A [40 marks] Answer all questions in this section 1. (a) The mass spectrum of a compound , X is shown below
Relative abundance
15 17
(i)
28 29 31
45
60
m/e
If the molecular formula of X is C3H8O , draw two possible structural isomers of X
[2] (ii)
Based on the mass spectrum given, identify the compound X. Give your reason
…………………………………………………………………………………. ………………………………………………………………………………… ……………………………………………………………………………….. [2]
papercollection
1. b) The diagram below shows four electron transitions in the hydrogen atom Energy n=5 n=4 n=3 n=2
n=1
(i)
Skecth the line spectrum formed as a result of these four transitions
[2] (ii)
In which region of the electromagnetic spectrum are these lines formed? ……………………………………………………………………………….. [1]
(iii)
By using the Rhyberg equation, calculate the frequency of the light emitted when an electron occupying the energy level n=3 drops to n=1. [Rhyberg constant for H atom = 1.097 x 107 m-1]
[3]
papercollection
2 (a) The following cell was set up between a zinc half-cell and an unknown metal, M half-cell. The standard e.m.f of the cell is 1.56 V. The zinc electrode is the anode in this cell.
M(s)
zinc rod
Zinc sulphate solution (1.0 moldm-3)
M+(1.0 moldm-3)
(i)
Give the name of a suitable substance to be used as the salt bridge. …………………………………………………………………………… [1]
(ii)
Write the cell diagram (cell notation) for the above cell. …………………………………………………………………………… [1]
(iii)
State the direction of electron flow through the voltmeter.
…………………………………………………………………………….. [1] (iv)
Use the Data Booklet to calculate the standard electrode potential of the system: M+(aq) + e-
M(s)
[2 ]
papercollection
(b) copper electrodes
Electrodes of metal X solution containig Xn+ ions
copper(II) sulphate solution
cell A
cell B
In an electrolysis experiment, two electrolytic cells A and B are connected in series as shown above. Cell A consists of copper electrodes immersed in an aqueous copper(II) sulphate solution. Cell B consists of electrodes of metal X immersed in an aqueous solution containing Xn+ ions. When a current of 0.50 A is allowed to pass through the two cells for 20.0 min, the masses of copper and X deposited in cell A and cell B are 0.197 g and 0.672 g respectively. [Relative atomic mass: Cu, 63.5, X, 108] (i)
Calculate the quantity of electricity that passed through the two cells.
[1 ] (ii)
Calculate the quantity of electricity that is required to deposit 1.00 mol of copper and 1.00 mol of X. Copper:
X:
[3] (iii)
Based on the results obtained in (ii) above, state the charge of the Xn+ ion. …………………………………………………………………………………………
papercollection
3
(a) Write the formula of the oxides of Period 3 elements of the Periodic Table in the boxes provided. Give only one formula for each element.
Element Formula of oxide
Na
Mg
Al
Si
S
Cl
[3] (b) Write equations for the reactions of aluminium oxide with the following reagents: (i) aqueous sodium hydroxide ……………………………………………………………………………………….... (ii) aqueous hydrochloric acid …………………………………………………………………................................... [2] (c) Strontium, Sr is an element in Group 2 of the Periodic Table. (i) Write a balanced equation for the action of heat on strontium nitrate ……………………………………………………………………………………….. (ii) Both magnesium nitrate and strontium nitrate will decompose on heating. Which of the two will decompose at a lower temperature? …………………………………………………………………………………………. (iii) Explain why your answer to (c) (ii) decomposes at a lower temperature. ………………………………………………………………………………………… ………………………………………………………………………………………. …………………………………………………………………………………………. [4] (d) Arrange the solubility of Group 2 sulphates in descending order . …………………………………………………………………………………………. [1]
papercollection
4.
The compound 1-chloro-2-phenylethene is a monomer from which an addition polymer can be obtained. (a) Draw the displayed structural formula showing two repeating units of of this addition polymer.
[1] (b) Write an equation and state conditions for the reaction between 1-chloro-2-phenylethene and hydrogen . Equation:……………………………………………………………………….. Conditions…………………………………………………………… ………. ………………………………………………………………………………… [2] (c) Chloroethene reacts with hydrogen chloride to produce compound A. On heating A with aqueous sodium hydroxide, compound B is formed. B gives an orange precipitate with 2,4 dinitrophenylhydrazine (i) suggest the structural formulae for A and B in the boxes below: A
B
(ii) Write the name of the reaction mechanism by which A is formed ………………………………………………………………………………….. [3]
papercollection
(d) When chloroethene reacts with bromine in tetrachloromethane, the product is a mixture of two isomers. Draw the structures of the two isomers.
[2] (e) Toluene reacts with ethanoyl chloride in the presence of anhydrous aluminium chloride as a catalyst. Write an equation for this reaction
……………………………………………………………………………...[1]
Section B [60marks] Answer any four questions in this section 5 (a) Define (i) standard enthalpy change of atomization. (ii) standard enthalpy change of formation (b) The table below provides information on energy changes that take place in the formation of copper (II) oxide. Enthalpy changes Cu(s) + ½ O2 (g) → CuO(s) Cu(s) → Cu(g) ½ O2 (g) → O (g) Cu(g) → Cu+ (g) + e Cu+(g) → Cu2+ (g) + e O(g) + e → O- (g) O-(g) + e → O2- (g)
Δ H ( kJmol-1) -155.2 +339.3 +249.0 +750.0 +2000.0 -140.0 +786.0
[2]
papercollection
i) Draw the Born – Haber cycle for copper (II) oxide in the form of an enthalpy level diagram. (ii) Use the enthalpy level diagram and the values given in the table above to calculate the lattice energy of copper (II) oxide. [7] (c) Explain the following observations: (i) Molten aluminium chloride is a non - electrolyte but an aqueous solution of aluminium chloride is a strong electrolyte. (ii) Aluminium chloride dissolves easily in an organic solvent but aluminium fluoride does not dissolve in the same organic solvent. [6]
6. (a) Define (i) pH and (ii) buffer solution
[2]
(b) Calculate the pH of (i) 0.100 mol dm-3 of aqueous ethanoic acid solution (ii) a buffer solution formed by dissolving 16.4 g of sodium ethanoate in 750 cm3 of water and then adding to 250 cm3 of 0.100 mol dm-3 ethanoic acid [Ka for ethanoic acid= 1.75 x 10-5 mol dm-3] [6 ] (c) The partition coefficient for a solute Q between ether and water is 12.50. (i) By referring to solute Q, ether and water, explain what is meant by the term partition law. (ii) Under what conditions is the partition law true? (iii) 8.00 g of Q was dissolved in 25.0 cm3 of water. Q was then extracted firstly with 25.0 cm3 of ether and secondly with two portions of 12.5 cm3 of ether. Determine in each case the mass of Q that remains in the aqueous layer. [7 ] 7. (a) 0.500 g of solid aluminium chloride was heated to 2000C at a pressure of 1.00 x 105 Pa. The volume of vapour formed at this temperature and pressure was found to be 73.6 cm3. Calculate the relative molecular mass of the vapour at this temperature and pressure. Draw a displayed formula to show the types of bonding in the molecules of the vapour. [4] (b) Explain with the help of equations why an aqueous solution of aluminium sulphate has a pH of 4.8
[3]
(c) Carbon and silicon are the first two elements in Group 14 of the Periodic Table. Carbon dioxide is a gas that dissolves in, and reacts with water. Silicon(IV) oxide is a solid that is insoluble in, and is unreactive towards water. The tetrachlorides of carbon and silicon are both liquids, one of which reacts with water and the other does not. Explain the differences in physical and chemical properties of these four compounds described by these statements, writing balanced equations for all reactions that occur. [8]
papercollection
8.
(a) How do the chloride, bromide and iodide ions differ in their reactions with (i) silver nitrate solution, followed by aqueous ammonia (ii) concentrated sulphuric acid In each case, suggest the products of the reaction and write equations where appropriate. [9] (b) What do you understand by the term transition element? State two properties of iron or its compounds that typify it as a transition element.
[3]
(c) Describe and explain what happens when an aqueous solution containing Cu2+ ions is added gradually with dilute aqueous ammonia followed by an aqueous solution of [EDTA] 4[3] 9. (a) Phenylmethanol and 4-methylphenol are structural isomers with the same molecular formula. State clearly how these two compounds will react with each of the following reagents, and write balanced equations for the reactions involved. (i) aqueous sodium hydroxide at room temperature (ii) aqueous bromine at room temperature [6] (b) The reaction scheme below shows two different organic compounds P and Q having the same molecular formula C3H6Cl2 reacting with aqueous potassium hydroxide to form compounds R and S respectively. R and S are then treated with 2,4 dinitrophenylhydrazine and in both cases an orange precipitate is formed. However only R gives a yellow precipitate when heated with iodine in sodium hydroxide solution. P
Q
KOH(aq)
KOH(aq)
R C3H6O 2,4-dinitro phenylhydrazine Orange Precipitate
S C3H6O I2 / OH-
Yellow Precipitate
2,4 -dinitrophenylhydrazine Orange Precipitate
(i) Write the structure formula of the group responsible for the positive test with - 2.4-dinitrophenylhydrazine - iodine in sodium hydroxide solution (ii) Draw the structural formulas of compounds R and S . (iii) Suggest a chemical test to distinguish between R and S (iv) Draw the structural formulas of P and Q (v) Write equations for the reactions of both P and Q with aqueous KOH solution [9]
papercollection
10. (a) A compound, A, has the molecular formula, C3H4OCl2. Compound A is a colourless liquid that fumes in moist air. It reacts with water to form compound B, C3H5O2Cl. B is optically active. When A is refluxed with aqueous sodium hydroxide and then acidified, compound C, C3H6O3, is obtained. (i) Identify A, B and C. Give reasons for your answers. (ii) Draw the structural formula of the compound formed in the reaction between 2-propanol with A. Write a balanced equation for this reaction [8] (b) Pentyl 4-metoxycinnamate, L, can absorb ultraviolet rays and is used in the production of skin cream. Its structural formula is as follows. O CH3O
CH=CH
C
O
CH2(CH2)3CH3
Molecule L
(i) State the type of isomerism that is shown by molecule L and draw the structures of these isomers. (ii) Draw the structural formulas of the products formed when L is heated with aqueous sodium hydroxide solution. (iii) L can be synthesised in the laboratory from the compound shown below. Name the reactant used and the conditions necessary for this synthesis.
CH3O
CH=CHCOOH [7]
papercollection
ANSWER TRIAL EXAM CHEMISTRY PAPER 1 2009
NO 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
ANSWER C B C A B C A B C B B C C B D B C A C B C D A B C
NO 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
ANSWER A D D B D A D A D A A B D A A A B D D B D D C B C
papercollection
Marking Scheme for Chemistry Paper 2 STPM Trial 2009 Q 1(a)
Answer (i) CH3CH2CH2OH
CH3CHCH3
1+1
OH
2
CH3—O—CH2CH3 (either two) (ii) Propan-1-ol / 1-propanol The peak at m/e 31 indicates the presence of CH2OH group 1(b)
∑
Mark
1 1
2
1
2
(i)
( 1 mark)
frequency wavelength
(ii) Ultraviolet (iii)
f = cx RH ( 1/n12 - 1/n22) = 3.0 x 108 x 1.097 x 107 m-1(1/12 - 1/32) = 2.93 x 1015 s-1
1
1
1
1 1 1
3
10 2(a)(i)
Saturated potassium chloride solution/Saturated potassium nitrate solution or any suitable saturated aqueous ionic salt solution (ii) Zn(s)/Zn2+(aq)//M+(aq)/M(s) (iii) From zinc to metal M
(iv) Eөcell= EөM- EөZn 1.56= EөM-(-0.76) EөM=0.80 V (b)(i) Number of coulomb = I x t = 0.50 x 20.0 x 60 = 600 C ( mark for final answer with unit) (ii) 0.197 g of Cu is deposited by 600 C l.0 mol of Cu is deposited by 63.5 x 600 C = 193 000 C 0.197 0.672 g of X is deposited by 600 C.
1
1 1
3 2
1 1
1
1
papercollection
l.0 mol of X is deposited by 108 x 600 C = 96 400 C 0.672 working shown in either above calculations award 1 mark (iii) Charge is X + / n = 1 Total 3 (a) Element : Na Mg Al Si S Cl Formula of oxide Na2O MgO Al2O3 SiO2 SO2 Cl2O Na2O2 SO3 Cl2O7 ( 5, 6 correct ---- 3 marks ( 3, 4 correct ---- 2 marks ( 2 correct ----- 1 mark (0, 1 correct ----- 0 mark) 3(b) Equation: Al2O3 + 2NaOH + 3H2O 2NaAl(OH)4 (i) 3(b) Equation: Al2O3 + 6HCl 2AlCl3 + 3H2O (ii) 3(c) (i) Equation: 2Sr(NO3)2 2SrO + 4NO2 + O2 3(c) Magnesium nitrate (ii) 3(c) Mg2+ has a higher charge density (iii) Mg2+ polarises / distorts the CO32- anion more strongly / weakens the C—O bond 3 (d) BeSO4 , MgSO4, CaSO4, SrSO4, BaSO4 Total 4 (a) H H H H │ │ │ │ —C—C—C—C— │ │ │ │ Cl Cl
1 1 1 10
3
1 1
2
1 1 1 1
4
1
1 10 1
1
4(b)
2 —CH=CHCl + H2
Equation:
Conditions: catalyst: Ni / Pd / Pt and heat 4 (c) (i)
4
1 1 2
B
A H H │ │ H—C—C—Cl │ │ H Cl
—CH2CH2Cl
H H │ │ H—C—C=O │ H
4(c)(ii) Mechanism: electrophilic addition
1 + 1
1
3
papercollection
4 (d)
2 Br
Br
C
C Cl
CH2Br
Cl
1 + 1
BrH2C H
H mirror
4 (e)
1+ CH3 │
+ 2 CH3—C—Cl ║ O
CH3 │
( 1mark)
CH3 │
1
C—CH3 + ║ O O=C—CH3 (1 mark) + 2HCl (optional) TOTAL
5 (a) (i)
(a) (ii)
2
The standard enthalpy change of atomization of an element is the heat absorbed when one mole of gaseous atoms is formed from the element in its standard state under standard conditions. The standard heat of formation of a substance is defined as the heat evolved or absorbed when one mole of the substance is formed from its elements under standard conditions.
10
1
1 2
papercollection
5 (b) (i)
Born-Haber Cycle Cu2+(g) + O 2-(g)
E (kJ) 2+
Cu (g) + O(g) + 2e ΔHEA ΔHat(O)
st 1
ΔHEA
(O)
nd 2
(O-)
Cu2+(g) + O-(g) + e
8x ½
Cu2+(g) + ½O2(g) + 2e
+ 1
ΔHIE 2nd Cu+(g)
ΔH1st өCuO
Cu+(g) + ½O2 (g) + e ΔHIE 1st Cu(g) Cu(g) + ½O2 (g)
ΔHat Cu(s) Cu(s) + ½O2(g) ΔHfөCuO(s)
CuO(s)
For each enthalpy change correctly shown in diagram above ------------ ½ x 8 = 4 marks Enthalpy diagram with E labeled -------1 mark
5
By Hess’s Law ΔHfө (CuO) = ΔHat ө(Cu) + ΔHIE1stө (Cu) + ΔHIE2ndө (Cu+) + ΔHatө (O) + ΔHEA1stө (O) + ΔHEA2ndө (O-) + ΔHlatө (CuO) -155.2
= (+339.3) + (+750.0) + (+2 000) + (+249) + (-140.0) + (+786.0) + ΔHlatө (CuO)
1
Lattice energy CuO = - 4139.5 kJmol-1
1
Molten- AlCl3 exists as simple covalent molecules. Aqueous- AlCl3 dissociates to form Al3+ / [Al(H2O)6]3+ and Cl- ions
1 1
2 c(i)
2
papercollection
c(ii)
AlCl3 is a covalent molecule. AlF3 is ionic compound Cl- ion is much larger than F- ion Al3+ polarises Cl- ion easily / Al3+ cannot polarise F- easily
1 1 1 1 4
6(a)(i)
pH is negative logarithm to the base 10 of the concentration of H+(aq) ions in mol dm-3 or pH = -lg [H+] (ii) Buffer solution- a solution which resists changes in pH when small amounts of an acid or alkali are added. (b)(i) Ka= [H+][CH3COO-] [CH3COOH] [H+]= [CH3COO-] 1.75 x 10-5 = [H+]2 or [H+] = √ Ka x c 0.100 [H+] = 1.32 x 10-3 pH= -log [H+] = -log (1.32 x 10-3) = 2.88 (ii) pH = pKa + lg [CH3COONa] [CH3COOH] = - lg (1.75 x 10-5) + lg [ (16.4/82.0) ] [ 250/1000 x 0.100 ] = 4.76 + lg ( 0.20 / 0.025) = 4.76 + 0.903 = 5.66 (c)(i) The partition law states that a solute, Q will distribute itself between the two immiscible solvents, ether and water until equilibrium is achieved. At equilibrium the ratio of the concentrations in the two solvents is constant or Concentration of Q in ether = 12.50 Concentration of Q in water (ii) The partition law holds true when the temperature is constant the solute is in the same molecular condition in both solvents / (no dissociation or association) low concentration ( any 2) (iii) Let x= amount of Q extracted by one portion of 25.0 cm3 of ether x / 25.0 ____________ = 12.50 8.00-x/25.0
1
1
1 1
1 1 1
1
1
1 1
1
x= 7.41 g 1 Amount of Q left in aqueous layer = 8.00 – 7.41 = 0.59 g
2
6
papercollection
1st extraction with 12.5 cm3 ether: Let y = amount of Q extracted by first 12.5 cm3 of ether y/ 12.5 ____________
= 12.50
8.00-y/25.0 Therefore amount extracted is 6.90 g 1 The amount of Q left in aqueous layer after first extraction is 8.00g – 6.90g = 1.10 g 2nd extraction with 12.5 cm3 of ether. Let z= amount of Q extracted by the 2nd portion of 12.5 cm3 of ether. z / 12.5 ____________
=
12.50
1.10 – z / 25.0 z = 0.95 g Hence amount left in aqueous layer =1.10 – 0.95 = 0.15 g
Q7 (a)
Mr
1 1 15
Total = ( m x R x T ) / pV = 0.500 x 8.31 x 473 1 1.00 x 105 x 73.6 x 10-6 = 267 1 covalent bond – anyone labelled correct shape ---- 1 Cl Cl: Cl 2 types of bonds 1+ 1 Al Al labelled ----- 1 Cl :Cl Cl coordinate bonding / dative bonding (both labelled)
7 (b)
max 4 marks
4
Aqueous solution of aluminium sulphate contains [Al(H2O)6]3+ / 1 hexaaqua aluminium ion This ion undergoes hydrolysis to produce H+ / H3O+ ions which 1 makes the solution acidic with a pH of 4.8. 1 Equation: Al(H2O)63+ + H2O [Al(H2O)5OH]2+ + H3O+ 3
7 (c)
Carbon dioxide - simple molecular structure with weak van der waals forces between molecules SiO2 has a macromolecular structure/ has a giant covalent structure with strong Si-O covalent bonds
1 1
papercollection
8 (a) (i)
(a) (ii)
(b)
CO2 dissolves slightly in water to produce carbonic acid or CO2 + H2O → H2CO3 Both CCl4 and SiCl4 are simple non-polar molecules CCl4 and SiCl4 are liquids, CO2 is gas because:the intermolecular forces in CCl4 or SiCl4 are stronger than in CO2 due to larger molecular size SiCl4 can be hydrolysed by water but CCl4 cannot Si has empty valence 3d orbitals to accept lone pairs of electrons to form dative bonds with water molecules Carbon has no 3d orbitals / no empty valence orbitals All the three halides react with aqueous silver nitrate to form precipitates / insoluble silver salts or Ag+ + X- → AgX AgCl is white, AgBr is cream/light yellow and AgI is yellow With aqueous ammonia, AgCl dissolves Ag+ + 2NH3 → Ag(NH3)2+ AgBr and AgI are insoluble in aqueous ammonia
1 1 1 1 1 8 1
1 1 1 1 1 5
X + H2SO4 → HX + HSO4 For Cl-, white fumes of HCl gas is evolved
1 1
For Br- white fumes of HBr and brown fumes of Br2 evolved For I-, purple (violet) vapour of I2 are evolved (equation for oxidation of HBr or HI to Br2 or I2)
1 1 1
is an element that forms at least a stable ion that has partially filled d-orbitals
1
-
-
Any two properties below (must give correct examples) green colour of aqueous Fe2+ / yellow colour of aqueous Fe3+ catalytic activity of Fe2+ / Fe3+ in the reaction between I- and S2O82- / Fe is a catalyst in the Haber process variable oxidation states +2 , +3, +6 (any 2) complex formation example [Fe(CN)6]3- / FeO42-
max 4
1+1
3 (c)
Blue precipitate of Cu(OH)2 is formed or Cu2+ + 2OH- → Cu(OH)2(s)
1
blue precipitate dissolves in excess ammonia to form a dark blue solution (complex) - [Cu(NH3)4]2+ or Cu(OH)2(s) + 4NH3 (aq) → [Cu(NH3)4]2+(aq) + 2OH- (aq) When EDTA is now added, the dark blue solution becomes lighter blue due to the formation of [Cu(EDTA)]2- complex or
1
papercollection
[Cu(NH3)4]2+ + [EDTA)]4- → [Cu(EDTA)]2- + 4NH3
1
3 15
9 (a) (i)
4-methylphenol dissolves in NaOH(aq) to form a soluble salt CH3
(a) (ii)
OH + NaOH
CH3
1
ONa + H2O 1
Phenylmethanol does not dissolve in NaOH(aq) 4-methylphenol decolourises bromine and forms a white precipitate
1 1
3
Br CH3
OH + 2Br2
CH3
OH+ 2 HBr 1 Br
Phenylmethanol – colour of Br2 remains unchanged and there is no white precipitate (b) (i)
1 3 1
C=O CH3 – C – 1
2
1+ 1
2
1
2
O (b) (ii) CH3 – C – CH3
(b) (iii)
CH3 – CH2 –C- H
O O Both R and S are heated with Tollen’s reagent / Fehling’s reagent S - metallic silver (silver mirror) is formed / brick red precipitate of Cu2O obtained and R - no silver mirror or metallic silver / no brick red precipitate
(b) (iv)
1
Cl CH3
C
CH3 (P) 1
Cl
papercollection
Cl
1 2
CH3
(b) (v)
CH2
C
H (Q)
Cl CH3COCH3 + 2KCl + H2O
CH3C(Cl2)CH3 + 2KOH CH3CH2CHCl2 + 2KOH
CH3CH2CHO + 2KCl + H2O
1 1
2 max 9
15 10 (a) (i)
B contains a chiral carbon because optically active A fumes in moist air, thus A has acyl functional group / -C-Cl ║ Structure B Hence, Structure A O H H Cl-C-COOH
1 1
1+1
Cl-C-COCl
CH3
CH3
Reaction of A with NaOH produces H
H
HO-C-COONa
1+1
HO-C-COOH
CH3
(C)
CH3
On acidification, C is obtained. (a) (ii) H + Cl-C-COCl
CH3-CH-CH3
_
OH CH3 CH3 Cl-CH-COOCH-CH3
+H
+
HCl
1+1 8
CH3 ( 1 mark for organic product) (1 mark for equation)
papercollection
(b)(i) Geometrical isomerism (cis-trans isomerism) for L H
1
H C=C 1
CH3O
COOCH2(CH2)3CH3
(cis isomer) H
COOCH2(CH2)3CH3 C=C
CH3O
(ii)
1 H
(trans-isomer ) Reaction of L with an aqueous solution of hot sodium hydroxide O 1 CH3O
CH=CH
C
and O-Na+
(c)
CH3(CH2)3 CH2OH Compound: 1- pentanol Conditions: concentrated sulphuric acid , reflux / heat Total
1 1 1 15
7
96211 IN(;KAJAN FN/LH DALHAfi S/:,RLHHAN PAN! rtA T!i\f;'/<",·i 1A \ IYtt..l Chemistry IRJ:,\4HAlV f~:\'\If!:l T1;V(i/
1-4 hours
r'/?,'t{l SFRFAllf:\N 1).:\;\'11'//\ TlNGl<:'\ [:iN 'I,ve ',',\,':~l i'VI IJ:if:.R .'~\ fI;! '"~'f'"'.[\Dj'tt l'); \' i '''/ r',!1. I;' " ,II';' f,; ~i ),'"
r:N:IA.f f),,\ER.iif SFI?FJ1IUN 'f'f'\'( .,' ,F',:V'''' h' , ';.1 i'.''J/ \/ \ '(', li\'"
f)':,f 1 .\:''/'j / ''\
,;ERF;UH'\;\ P(\r\ITf/\ Tf/\'(/!{frT'1iV FNk'd f)/';FR:Hf SF;r?F'tflU/v I'AN1J1A n.NGK,:HAN j JABATAN PELAJARAN NEGERI {jZ'l'ffl.,lERAIl SL,REJ{B:\N p:, NEGERI SEMBILAN DARUL KHUSUS '\ 11:\G/\/\1:\:\' F!YAM UALR/ if ," rel="nofollow">LRFM1J:\,\J
_
, "c."",
PEPERIKSAAN PERCUBAAN \J\fAA LVAM :),';~::?~ll: ,:/,:,1<: SIllL TINGGI PERSEKOLAHAN MALAYSIA ?~AiV l)ANf;nA j'ANIT1A
nN(
n"(II..:\ lAd
"Lit U1Uv\/f
j
S1~.Rl';''\4HA!V p; I'.-'!YAM
2009
fJ4LRAIf
.'·;FREMrI4;V PANlTfA
nW,'KAf/\!V Fi\'Aiti
A 11\(/I
lJAJ:,'/?:l.f/
,<;rRr:MH.V";
DO NOT OPEN THIS BOOKLET UNTIL YOU ARE TOLD TO DO SO Instructions to candidates: There are fifty questions in this paper. For each question, four suggested answers are given. Choose one correct answer and indicate it on the multi-choice answer sheet provided. Read the instructions on the multiple-choice answer sheet very carefully, Answer all questions. Marks will not be deducted for wrong answers. A Data Booklet is provided.
This question paper consists of 18 printed pages [Turn Over
96211 © Sept
2008
Copyright PPD Seremban
papercollection
Confidential*
2 Section A
Four suggested answers labelled A, B, C, and D are given for each question. Choose one correct answer.
1
A manometer is a device for measuring gas pressures. A sample of nitrogen gas is placed in a close-end manometer at 25°C until there is an increase of 0.100 g in its mass. The diagram below shows the height of mercury in the manometer.
What is the volume of the nitrogen gas in the manometer? [Relative atomic mass: N=14.0; molar gas constant = 8.31 J K–1 mol–1; 760 mm Hg = 101 kPa]
2
A
95 cm3
B
111 cm3
C
133 cm3
D
266 cm3
Which of the following statements is true of the hydrogen line spectrum? A
The number of lines in each series is the same.
B
The first line in each series has the lowest frequency.
C
The lines in a series become closer when the frequency decreases.
D
The ionisation energy of hydrogen can be calculated from the frequency of the first line of the Lyman series.
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential* 3
3
The phase diagram for iodine is shown below.
Which of the following statements is true?
4
A
Point C is the critical temperature.
B
At point B, solid iodine and liquid iodine exist in equilibrium.
C
The line OC represents the effect of pressure on the melting point of iodine.
D
Iodine sublimes when heated from room temperature to 120 °C at a constant pressure of 14 kPa.
The following graph shows the variation of a physical property of Period 3 elements (sodium to argon) in the Periodic Table.
A
Enthalpy of vaporisation
B
Electrical conductivity
C D
First ionisation energy Electronegativity
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential* 5
4
The elements X and Y have the following electronic configuration. X : 1s2 2s2 2p6 3s2 Y : 1s2 2s2 2px2 2py2 2pz2 When X reacts with Y, what is the formula of the compound and the most likely type of bond formed?
6
7
8
Formula
Type of bond
A B C
X2Y2 XY2 X2Y
Ionic Ionic Covalent
D
X2Y3
Covalent
Which of the following substances has the strongest intermolecular force in its liquids state? A
NH3
B
CH4
C D
C2H5OH CO2
Which of the following species does not involve the formation of dative bonds? A
SO42-
B
NH4+
C
NO3-
D
[ Cu (NH3)4 ] 2+
The synthesis of ammonia from hydrogen and nitrogen is an exothermic reaction. Which of the following will increase both the rate of the forward reaction and the yield of ammonia ? A
Decreasing the pressure
B
Increasing the pressure
C
Increasing the temperature
D
Increasing the quantity of catalyst used
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential* 9
5
The energy diagram for three substances P,Q and R are shown below. P Q R
Valence band
Valence band Valence band
Which of the following combination is correct?
A B C
P conductor semi-conductor conductor
Q non-conductor non-conductor semi-conductor
R semi-conductor conductor non-conductor
D
non-conductor
semi-conductor
semi-conductor
The equilibrium constant, Kc , for these reaction
10
2NH3 (g) + 3CuO (s) A
[Cu] 3 [N2] [H2O]3 [NH3] 2 [CuO] 3
B
[N2] [H2O]3 [NH3]2
C
[N2] [H2O]3 [NH3]
D
3[N2] [H2O] 2[ NH3]
3Cu(s) + N2 (g) + 3H2O (g)
11 What is the pH of the solution formed when 50.0 cm3 of 0.10 mol dm-3 aqueous ammonia is mixed with 20.0 cm3 of 0.05 mol dm-3 aqueous ammonium chloride ? [pKb for ammonia = 4.75] A
10.3
B
9.95
C D
8.12 7.61
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
6
12 50 cm3 of aqueous silver nitrate (V) is added to 50 cm3 of 0.20 moldm-3 aqueous sodium chloride. What is the minimum concentration of silver nitrate (V) solution in moldm-3 needed to precipitate silver chloride? [ Ksp of AgCl = 2.0 x 10-10 mol2 dm-6 ] A
1.0 x 10-9
B
4.0 x 10-9
C
2.0 x 10-10
D
2.0 x 10-11
13 A solution of 5.0 g of an organic compound Q in 50 cm3 of water was shaken with 100 cm3 of ether. After separation, the aqueous solution was found to contain 0.98 g of Q. What is the partition coefficient of Q between ether and water? A B C
6.250 2.625 2.050
D
1.825
14 The diagram shows the boiling point-composition of a mixture of two liquids P and Q. Temperature
Z
1.0 Xp What is the composition of the distillate if a mixture of composition Z is fractionally distilled? 0
A B C
Pure P Azeotropic mixture Pure P and azeotropic mixture
D
Pure Q and azeotropic mixture
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential*
7
15 An electrochemical cell is prepared by using a copper electrode immersed in an aqueous solution of copper(II) sulphate solution and a platinum electode immersed in an aqueous solution of potassium chlorate(I). The standard electrode potentials of the two half-cells are as follows Cu Cu2+ + 2eClO + H2O + 2e
Cl- + 2OH-
Eθ = +0.34 V Eθ = +0.89 V
Which of the following statements is not true for the above cell? A
The e.m.f of the cell is 0.55 V
B
The copper electrode is the anode
C
The chlorate(I) ion acts as an oxidising agent
D
Electrons flow from the platinum electrode to the copper electrode
16 A steady current flows through an aqueous solution of potassium iodide for 4825 seconds. The iodine produced requires 12.5 cm3 of 0.80 mol dm-3 sodium thiosulphate(VI) for complete reaction. What is the value of the current flowing in this electrolytic cell? [ I2 ≡ 2S2O32- ; 1F = 96, 500 C mol-1] A
0.1 A
B
0.2 A
C
0.3 A
D
0.4 A
17 A certain quantity of electricity produces 2.94 g of copper when an aqueous solution of copper(II) sulphate solution is electrolysed. When the same amount of charge is passed through an aqueous solution containing the Xn+ ions, 6.0 g of X is produced. What is the value of n? [ Cu = 63.5; X = 197 ] A
1
B
2
C
3
D
4
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
8
18 Which of the following processes involves the enthalpy change of formation? A
H2(g) + O2(g) H2O2(l)
B
CO(g) + ½ O2(g)
C
2N(g) + 3H2(g) 2NH3(g)
D
Mg(s) + C(s) + 3O2(g)
CO2(g) MgCO3(s)
19 Consider the following neutralisation reactions below:NaOH(aq) + HCl(aq) NaCl(aq) + H2O(l) NaOH(aq) + ½ H2SO4(aq) ½ Na2SO4(aq) + H2O(l)
∆H1 = -57.3 kJ ∆H2 = -66.5 kJ
∆H2 is more negative than ∆H1 because:A
H2SO4 is a stronger acid than HCl
B
the lattice energy of HCl is higher than that of H2SO4
C
the heat of dilution of H2SO4 is much larger than that of HCl
D
H2SO4 dissociates completely in water while HCl only dissociates partially.
20 Which of the following electronic configuration of elements is most likely to react with steam than water? A
1s22s22p63s1
B
1s22s22p63s2
C
1s22s22p63s23p1
D
1s22s22p63s23p2
21 Which one of the following reactions is characteristic of aluminium hyroxide? A
It reacts with sulphuric acid to give a white precipitate of aluminium sulphate.
B
It fumes in the presence of hydrochloric acid because volatile aluminium chloride is formed. It dissolves in aqueous sodium hydroxide to give a solution of sodium aluminate. It reacts with aqueous sodium hydroxide to give a white precipitate of sodium aluminate.
C D
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential*
9
22 Silicon (IV) oxide is a solid whereas carbon (IV) oxide is a gas. This is because A
carbon is more electronegative than silicon
B
the silicon-oxygen bond is stronger than the carbon-oxygen bond
C
silicon(IV) oxide partially ionic whereas carbon(IV) oxide is purely covalent
D
silicon (IV) oxide is a giant molecule whereas carbon (IV) oxide is a simple molecule.
23 When CO2 gas is passed through limewater, a white precipitate of CaCO3 is formed. If an excess of CO2 is passed through, the white precipitate dissolves because
C
as more and more CO2 gas dissolves, the solution becomes increasingly acidic, hence CaCO3 changes to CaHCO3 which is soluble. as more and more CO2 gas dissolves, the solution becomes increasingly acidic and CaCO3 will decompose as more and more CO2 gas dissolves, a soluble complex is formed.
D
the precipitate CaCO3 will react with an excess of CO2 to form CaO
A B
24 In the Haber process, nitrogen gas is obtained from A
reduction of nitrogen dioxide
B
fractional distillation of liquefied air
C
catalytic decomposition of hydrazine
D
thermal decomposition of ammonium salts
25 Chlorine gas is bubbled through aqueous sodium hydroxide.What is the use of the solution obtained? A
Deodorant
B
Antiseptic
C
Bleaching agent
D
Aerosol propellant
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
10
26 In which of the following compounds is the transition metal having the highest oxidation state? A
K2CrO4
B
MnC2O4
C
NH4VO3
D
K4Fe(CN)6
27 Nickel is used as a catalyst in the hydrogenation of unsaturated fatty acids to saturated fatty acid in the manufacture of margarine. How does nickel help in the reaction? A
Nickel does not react with the products
B
Nickel shows variable oxidation number
C
Nickel has available d orbitals for bonding
D
Nickel forms a stable intermediate with the reactants
28 1,3-butadiene, is used to synthesis SBR rubber. How many pi (п) and sigma (σ) bonds are present in one molecule of 1,3-butadiene? Number of pi (п) bonds
Number of sigma (σ) bonds
A
1
7
B
1
9
C
2
7
D
2
9
29 From the dibromination of propane , four isomeric products with the formula C3H6Br2, were isolated. . However, only one of the products, S, shows optical activity. What is the structural formula of S? A
1,1-dibromopropane
B
1,2-dibromopropane
C
1,3-dibromopropane
D
2,2-dibromopropane
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential*
11
30 Which one of the following is correct about 1-butene and 2-butene? A
Exhibits cis-trans (geometrical) isomerism
B
Reacts with bomine to give 1,4-dibromobutane
C
Oxidized by hot acidified potassium manganate(VII) to diols.
D
Reacts with hydrogen in the present of Nickel to form butane
31 Which property of benzene may be directly attributed to the stability associated with its delocalized electrons? A
It tends to undergo substitution rather than addition reactions
B
It is susceptible to attack by nucleophilic reagents
C
Its enthalpy change of formation is positive
D
It does not conduct electricity
32 An organic halogen compound X was boiled with aqueous sodium hydroxide. When aqueous silver nitrate solution was then added to the mixture, little or no precipitate was obtained. Which of the following formulae could represent compound X? A
CH3CH2CHCH2CH3
C —CH2Cl
Cl B
CH3CH2CH2COCl
D
—Cl CH3
33 An organic compound L gives a yellow precipitate when heated with a solution of iodine in sodium hydroxide. Which of the following compounds could be L? A
CH3CH2CH2CH(OH)CH3
B
(CH3)2CHCOCH(CH3)2
C
(CH3)2C(OH)CH2CH3
D
CH3CH2COCH2CH3
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
12
34 An organic compound M has the following properties:• • •
optically active. reacts with 2,4 dinitrophenylhydrazine to give an orange precipitate releases hydrogen chloride gas when reacted with phosphorus pentachloride.
The structural formula of M is A HOCH 2— HOCH2CH 2CH 2—
—C—CH —C—CH33 ║║ OO
HOCH2—
—C—CH2CH3 ║ O
B
C HO—
—C—CH—CH3 ║ │ O CH3
D —C—CH—CH —C—CH—CH22OH OH ║║ ││ O O CH CH33 35 The best method to prepare phenyl benzoate is by A
mixing benzoyl chloride with phenol dissolved in aqueous sodium hydroxide
B
mixing benzoyl chloride with phenylmethanol.
C
refluxing benzoic acid with phenylmethanol.
D
refluxing benzoic acid with phenol.
36 What is the compound formed when dimethylamine, (CH3)2NH is reacted with nitrous acid? A
(CH3)2N – N = O
B
CH3CH2OH
C D
(CH3)2NOH (CH3)2N = N+
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential*
13
37 The following reaction scheme shows how propanone is changed to an ester. I CH3COCH3
II Y
C6H5COOCH(CH3)2
What are the reagent I and II in the above scheme? I
II
A
LiAlH4
C6H5OH
B
LiAlH4
C6H5COCl
C
NH3
C6H5CH2CI
D
H2
C6H5CH2COOH
38 Dopamine is a drug used in the treatment of Parkinson’s disease. HO HO
OH OH NH NH2 2 CH CH22CH CH CO CO2H 2H
Which one of the following statements about this compound is incorrect? A
It can be use to produce esters
B
It can exist in optically active forms
C D
It can exist as a zwitterion in aqueous solution One mole will react with one mole of sodium hydroxide to form a salt
39 Which of the following will react with 1,2-ethanediol to form a polymer? A
HOOCC6H4COOH
B
HOOC(CH2)4OH
C D
HOC6H4COOH C6H5COOH
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
14
40 The synthetic rubber, SBR is prepared by the reaction between:A
CH2=CH—CH=CH2
B
CH2=C—CH=CH2 │ CH3
and
and
CH=CH2 │
CH=CH2 │
C
CH2=CH—CH=CH2 and CH2=C—CH=CH2 │ CH3
D
CH2=C—CH=CH2 │ Cl
and CH2=CH—CH=CH2
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential*
15 Section B
For each of the questions in this section one or more of the three numbered statements 1 to 3 may be correct. Decide whether each of the statements is or is not correct. The responses A to D should be selected on the basis of the following. A 1 only is correct.
B 1 and 2 only are correct.
C 2 and 3 only are correct.
D 1, 2, and 3 are correct.
41 The mass spectrum of an element X is shown below.
1
Element X consists of two isotopes with relative isotopic mass of 14 and 15
2
The isotopes of X have a different number of protons
3
The nucleon number of X is 14.5
42 Which of the following statement(s) is/are true about the elements in Group 2 of the Periodic Table? 1
They are reducing agents
2
The ionic radius increases down the group
3
The electronegativity increases down the group
43 Which of the following statement(s) about methane, ammonia and water is/are correct? 1
The bond angle in methane is larger than the bond angle in ammonia
2
The C-H bond in methane is longer than the O-H bond in water
3
The bond angle in ammonia is larger than the bond in water
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
16
A 1 only is correct.
B 1 and 2 only are correct.
C 2 and 3 only are correct.
D 1, 2, and 3 are correct.
44 Ethanoic acid is a weak acid and hydrochloric acid is a strong acid . It follows that the 1 2 3
solution containing 0.100 mol dm-3 ethanoic acid and 0.100 mol dm-3 sodium ethanoate will be a good buffer solution formed by mixing equal number of moles of sodium hydroxide and ethanoic acid will have a pH of more than 7 pH of 0.100 mol dm-3 hydrochloric acid will be less than that of 0.100 mol dm-3 ethanoic acid.
45 Consider the following reaction 2MO3- + SO32- + 6H+ 2MO2+ + SO42- + 3 H2O It can be concluded that 1
the conversion of MO3- to MO2+ involves the transfer of 1 mol of electrons
2
the MO3- ion acts as an oxidising agent
3
the H+ ion is reduced to H2O
46 The Group 14 element germanium is widely used in the manufacture of semiconductors and other electronic components. The existence of this element in Group 14 between silicon and tin was predicted by Mendeleev some years before it was discovered. From its position in the group, what properties of germanium may be predicted? 1
GeCl4 is volatile liquid at room temperature.
2
Its most stable oxide has the formula GeO2
3
The oxides GeO2 forms ions GeO32-
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
Confidential*
17
A 1 only is correct.
B 1 and 2 only are correct.
C 2 and 3 only are correct.
D 1, 2, and 3 are correct.
47 Which of the following statement(s) regarding the hydrogen halide is/are true? 1
All are gas at room condition
2
The acidic strength increases in the order HCl < HBr < HI
3
The strength of the H-X bond increases in the order HI < HBr < HCl
48 Which of the following statements suggest the presence of free radicals in the chlorination of methane? 1
Hydrogen chloride is the major product
2
Ethane is present in small quantities in the product
3
The reaction proceeds most quickly in sunlight or ultraviolet light
49 Which of the following pairs of compounds will react together followed by hydrolysis, to form a compound with the structure below? CH3 │ CH3CH2 —C—OH │
1 —MgBr with
CH3COCH2CH3
2 —C—CH3 with CH3CH2MgBr ║ O 3 —C—CH3 with ║ O
CH3MgBr.
962/1 This question paper is CONFIDENTIAL until the examination is over
[Turn over] CONFIDENTIAL*
papercollection
Confidential*
A 1 only is correct.
18
B 1 and 2 only are correct.
C 2 and 3 only are correct.
D 1, 2, and 3 are correct.
50 Which of the following compounds can react with excess acidified potassium manganate(VII) solution and the product formed liberate a gas that turns lime water chalky with sodium carbonate? 1
CH3CH(CH3)OH
2
CH3CH2CH2OH
3
CH3CH(CH3)CHO
962/1 This question paper is CONFIDENTIAL until the examination is over
CONFIDENTIAL*
papercollection
CONFIDENTIAL *
<:Iass: ....................................... .
N arne: ...................................... .
:GERISEMBILAN JA lAB/LAN JABATAfI :GERISEMBILAN JA ItBILAN JABATA/\ :GERISEMBILAN JA JABATAfI IABILAN JABATAI\ . ..... ~ WI .. " .. w. w .....:GERISEMBILAN JALJI ,. I .... ..... ~ 'VI " " " •• w..... """ ...... ",-, ...... AB/LAN JABATANPELAJARANNEGERISEMBILAN JABATANPELAJARANNEGERISEMBILAN JABA TANPELAJARANNEGERISEMBILAN JABATANPELAJARANNEGERISEMBILAN JABA TANPELAJARANNEGER/SEMBILAN JABA TANPELAJARANNEGERISEMB/LAN JABATANPELAJARANNEGER/SEMBILAN JABATANPELAJARANNEGERISEMBILAN JABATANPELAJARANf'v AJARANNEGERISEMB/LAN JABATANPELAJARANN AJARANNEGERISEMBILAN JABATANPELAJARANf'v ___ . " __ "'_'_" __ .. _ ...... _. _-AJARANNEGERISEMBILAN JABATANPEL A.IARANNFr,FRISFMRII AN .IARATANPFI A.IARANNEGERISEMBILAN JABATANPEL Paper 2 EGERISEMBILAN JABATANPEL EGER/SEMB/LAN JABA TANPELMvl'1rv1IVIVc0cnluCIVIDtLMIV vI'1Dl'1ll'1tVrCLMvl'1rv1IVlvEGER/SEMBILAN JABA TANPELAJARANNEGERI,"""'· ..... ANPELAJARANNEGERISEMB/LAN JABATANPELAJARANNEGERf. (2 ~ hours) -ANPELAJARANNEGERISEMBILAN ~NPELAJARANNEGERISEMBILAN JABA TA NPELA JA RA NNEGERI, JABA TANPELAJARANNEGER/ JABA TANPELAJARANNEGERISEMB/LAN
962/2
STPM 2009
CHEMISTRY
II
•••
• . . . . . . "T"
JABATAN PELAJARAN NEGERl SEMBILAN PERCUBAAN BERSAMA SIJIL TINGGI PERSEKOLAHAN MALAYSIA
2009 Instructions to candidates:
For examiner's use
1 DO NOT OPEN TIDS QUESTION PAPER UNTIL YOU ARE TOLD TO DO SO.
2
3 Answer all questions in Section A. Write your answers in the spaces provided
4 5
Answer any four questions in Section B. Write your answers on your own test pad Begin each answer on a fresh sheet ofpaper. Answers should be illustrated by large and clearly labeled diagrams wherever suitable.
6 7
8
Arrange your answers in numerical order and tie the answer sheets to this question paper.
9 10 Total
This question paper consists of 11 printed pages STPM TRIAL 96212
CONFIDENTIAL *
papercollection
Section A [40 marks] Answer all questions in this section 1. (a) The mass spectrum of a compound , X is shown below
Relative abundance
15 17
(i)
28 29 31
45
60
m/e
If the molecular formula of X is C3H8O , draw two possible structural isomers of X
[2] (ii)
Based on the mass spectrum given, identify the compound X. Give your reason
…………………………………………………………………………………. ………………………………………………………………………………… ……………………………………………………………………………….. [2]
papercollection
1. b) The diagram below shows four electron transitions in the hydrogen atom Energy n=5 n=4 n=3 n=2
n=1
(i)
Skecth the line spectrum formed as a result of these four transitions
[2] (ii)
In which region of the electromagnetic spectrum are these lines formed? ……………………………………………………………………………….. [1]
(iii)
By using the Rhyberg equation, calculate the frequency of the light emitted when an electron occupying the energy level n=3 drops to n=1. [Rhyberg constant for H atom = 1.097 x 107 m-1]
[3]
papercollection
2 (a) The following cell was set up between a zinc half-cell and an unknown metal, M half-cell. The standard e.m.f of the cell is 1.56 V. The zinc electrode is the anode in this cell.
M(s)
zinc rod
Zinc sulphate solution (1.0 moldm-3)
M+(1.0 moldm-3)
(i)
Give the name of a suitable substance to be used as the salt bridge. …………………………………………………………………………… [1]
(ii)
Write the cell diagram (cell notation) for the above cell. …………………………………………………………………………… [1]
(iii)
State the direction of electron flow through the voltmeter.
…………………………………………………………………………….. [1] (iv)
Use the Data Booklet to calculate the standard electrode potential of the system: M+(aq) + e-
M(s)
[2 ]
papercollection
(b) copper electrodes
Electrodes of metal X solution containig Xn+ ions
copper(II) sulphate solution
cell A
cell B
In an electrolysis experiment, two electrolytic cells A and B are connected in series as shown above. Cell A consists of copper electrodes immersed in an aqueous copper(II) sulphate solution. Cell B consists of electrodes of metal X immersed in an aqueous solution containing Xn+ ions. When a current of 0.50 A is allowed to pass through the two cells for 20.0 min, the masses of copper and X deposited in cell A and cell B are 0.197 g and 0.672 g respectively. [Relative atomic mass: Cu, 63.5, X, 108] (i)
Calculate the quantity of electricity that passed through the two cells.
[1 ] (ii)
Calculate the quantity of electricity that is required to deposit 1.00 mol of copper and 1.00 mol of X. Copper:
X:
[3] (iii)
Based on the results obtained in (ii) above, state the charge of the Xn+ ion. …………………………………………………………………………………………
papercollection
3
(a) Write the formula of the oxides of Period 3 elements of the Periodic Table in the boxes provided. Give only one formula for each element.
Element Formula of oxide
Na
Mg
Al
Si
S
Cl
[3] (b) Write equations for the reactions of aluminium oxide with the following reagents: (i) aqueous sodium hydroxide ……………………………………………………………………………………….... (ii) aqueous hydrochloric acid …………………………………………………………………................................... [2] (c) Strontium, Sr is an element in Group 2 of the Periodic Table. (i) Write a balanced equation for the action of heat on strontium nitrate ……………………………………………………………………………………….. (ii) Both magnesium nitrate and strontium nitrate will decompose on heating. Which of the two will decompose at a lower temperature? …………………………………………………………………………………………. (iii) Explain why your answer to (c) (ii) decomposes at a lower temperature. ………………………………………………………………………………………… ………………………………………………………………………………………. …………………………………………………………………………………………. [4] (d) Arrange the solubility of Group 2 sulphates in descending order . …………………………………………………………………………………………. [1]
papercollection
4.
The compound 1-chloro-2-phenylethene is a monomer from which an addition polymer can be obtained. (a) Draw the displayed structural formula showing two repeating units of of this addition polymer.
[1] (b) Write an equation and state conditions for the reaction between 1-chloro-2-phenylethene and hydrogen . Equation:……………………………………………………………………….. Conditions…………………………………………………………… ………. ………………………………………………………………………………… [2] (c) Chloroethene reacts with hydrogen chloride to produce compound A. On heating A with aqueous sodium hydroxide, compound B is formed. B gives an orange precipitate with 2,4 dinitrophenylhydrazine (i) suggest the structural formulae for A and B in the boxes below: A
B
(ii) Write the name of the reaction mechanism by which A is formed ………………………………………………………………………………….. [3]
papercollection
(d) When chloroethene reacts with bromine in tetrachloromethane, the product is a mixture of two isomers. Draw the structures of the two isomers.
[2] (e) Toluene reacts with ethanoyl chloride in the presence of anhydrous aluminium chloride as a catalyst. Write an equation for this reaction
……………………………………………………………………………...[1]
Section B [60marks] Answer any four questions in this section 5 (a) Define (i) standard enthalpy change of atomization. (ii) standard enthalpy change of formation (b) The table below provides information on energy changes that take place in the formation of copper (II) oxide. Enthalpy changes Cu(s) + ½ O2 (g) → CuO(s) Cu(s) → Cu(g) ½ O2 (g) → O (g) Cu(g) → Cu+ (g) + e Cu+(g) → Cu2+ (g) + e O(g) + e → O- (g) O-(g) + e → O2- (g)
Δ H ( kJmol-1) -155.2 +339.3 +249.0 +750.0 +2000.0 -140.0 +786.0
[2]
papercollection
i) Draw the Born – Haber cycle for copper (II) oxide in the form of an enthalpy level diagram. (ii) Use the enthalpy level diagram and the values given in the table above to calculate the lattice energy of copper (II) oxide. [7] (c) Explain the following observations: (i) Molten aluminium chloride is a non - electrolyte but an aqueous solution of aluminium chloride is a strong electrolyte. (ii) Aluminium chloride dissolves easily in an organic solvent but aluminium fluoride does not dissolve in the same organic solvent. [6]
6. (a) Define (i) pH and (ii) buffer solution
[2]
(b) Calculate the pH of (i) 0.100 mol dm-3 of aqueous ethanoic acid solution (ii) a buffer solution formed by dissolving 16.4 g of sodium ethanoate in 750 cm3 of water and then adding to 250 cm3 of 0.100 mol dm-3 ethanoic acid [Ka for ethanoic acid= 1.75 x 10-5 mol dm-3] [6 ] (c) The partition coefficient for a solute Q between ether and water is 12.50. (i) By referring to solute Q, ether and water, explain what is meant by the term partition law. (ii) Under what conditions is the partition law true? (iii) 8.00 g of Q was dissolved in 25.0 cm3 of water. Q was then extracted firstly with 25.0 cm3 of ether and secondly with two portions of 12.5 cm3 of ether. Determine in each case the mass of Q that remains in the aqueous layer. [7 ] 7. (a) 0.500 g of solid aluminium chloride was heated to 2000C at a pressure of 1.00 x 105 Pa. The volume of vapour formed at this temperature and pressure was found to be 73.6 cm3. Calculate the relative molecular mass of the vapour at this temperature and pressure. Draw a displayed formula to show the types of bonding in the molecules of the vapour. [4] (b) Explain with the help of equations why an aqueous solution of aluminium sulphate has a pH of 4.8
[3]
(c) Carbon and silicon are the first two elements in Group 14 of the Periodic Table. Carbon dioxide is a gas that dissolves in, and reacts with water. Silicon(IV) oxide is a solid that is insoluble in, and is unreactive towards water. The tetrachlorides of carbon and silicon are both liquids, one of which reacts with water and the other does not. Explain the differences in physical and chemical properties of these four compounds described by these statements, writing balanced equations for all reactions that occur. [8]
papercollection
8.
(a) How do the chloride, bromide and iodide ions differ in their reactions with (i) silver nitrate solution, followed by aqueous ammonia (ii) concentrated sulphuric acid In each case, suggest the products of the reaction and write equations where appropriate. [9] (b) What do you understand by the term transition element? State two properties of iron or its compounds that typify it as a transition element.
[3]
(c) Describe and explain what happens when an aqueous solution containing Cu2+ ions is added gradually with dilute aqueous ammonia followed by an aqueous solution of [EDTA] 4[3] 9. (a) Phenylmethanol and 4-methylphenol are structural isomers with the same molecular formula. State clearly how these two compounds will react with each of the following reagents, and write balanced equations for the reactions involved. (i) aqueous sodium hydroxide at room temperature (ii) aqueous bromine at room temperature [6] (b) The reaction scheme below shows two different organic compounds P and Q having the same molecular formula C3H6Cl2 reacting with aqueous potassium hydroxide to form compounds R and S respectively. R and S are then treated with 2,4 dinitrophenylhydrazine and in both cases an orange precipitate is formed. However only R gives a yellow precipitate when heated with iodine in sodium hydroxide solution. P
Q
KOH(aq)
KOH(aq)
R C3H6O 2,4-dinitro phenylhydrazine Orange Precipitate
S C3H6O I2 / OH-
Yellow Precipitate
2,4 -dinitrophenylhydrazine Orange Precipitate
(i) Write the structure formula of the group responsible for the positive test with - 2.4-dinitrophenylhydrazine - iodine in sodium hydroxide solution (ii) Draw the structural formulas of compounds R and S . (iii) Suggest a chemical test to distinguish between R and S (iv) Draw the structural formulas of P and Q (v) Write equations for the reactions of both P and Q with aqueous KOH solution [9]
papercollection
10. (a) A compound, A, has the molecular formula, C3H4OCl2. Compound A is a colourless liquid that fumes in moist air. It reacts with water to form compound B, C3H5O2Cl. B is optically active. When A is refluxed with aqueous sodium hydroxide and then acidified, compound C, C3H6O3, is obtained. (i) Identify A, B and C. Give reasons for your answers. (ii) Draw the structural formula of the compound formed in the reaction between 2-propanol with A. Write a balanced equation for this reaction [8] (b) Pentyl 4-metoxycinnamate, L, can absorb ultraviolet rays and is used in the production of skin cream. Its structural formula is as follows. O CH3O
CH=CH
C
O
CH2(CH2)3CH3
Molecule L
(i) State the type of isomerism that is shown by molecule L and draw the structures of these isomers. (ii) Draw the structural formulas of the products formed when L is heated with aqueous sodium hydroxide solution. (iii) L can be synthesised in the laboratory from the compound shown below. Name the reactant used and the conditions necessary for this synthesis.
CH3O
CH=CHCOOH [7]
papercollection
ANSWER TRIAL EXAM CHEMISTRY PAPER 1 2009
NO 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
ANSWER C B C A B C A B C B B C C B D B C A C B C D A B C
NO 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
ANSWER A D D B D A D A D A A B D A A A B D D B D D C B C
papercollection
Marking Scheme for Chemistry Paper 2 STPM Trial 2009 Q 1(a)
Answer (i) CH3CH2CH2OH
CH3CHCH3
1+1
OH
2
CH3—O—CH2CH3 (either two) (ii) Propan-1-ol / 1-propanol The peak at m/e 31 indicates the presence of CH2OH group 1(b)
∑
Mark
1 1
2
1
2
(i)
( 1 mark)
frequency wavelength
(ii) Ultraviolet (iii)
f = cx RH ( 1/n12 - 1/n22) = 3.0 x 108 x 1.097 x 107 m-1(1/12 - 1/32) = 2.93 x 1015 s-1
1
1
1
1 1 1
3
10 2(a)(i)
Saturated potassium chloride solution/Saturated potassium nitrate solution or any suitable saturated aqueous ionic salt solution (ii) Zn(s)/Zn2+(aq)//M+(aq)/M(s) (iii) From zinc to metal M
(iv) Eөcell= EөM- EөZn 1.56= EөM-(-0.76) EөM=0.80 V (b)(i) Number of coulomb = I x t = 0.50 x 20.0 x 60 = 600 C ( mark for final answer with unit) (ii) 0.197 g of Cu is deposited by 600 C l.0 mol of Cu is deposited by 63.5 x 600 C = 193 000 C 0.197 0.672 g of X is deposited by 600 C.
1
1 1
3 2
1 1
1
1
papercollection
l.0 mol of X is deposited by 108 x 600 C = 96 400 C 0.672 working shown in either above calculations award 1 mark (iii) Charge is X + / n = 1 Total 3 (a) Element : Na Mg Al Si S Cl Formula of oxide Na2O MgO Al2O3 SiO2 SO2 Cl2O Na2O2 SO3 Cl2O7 ( 5, 6 correct ---- 3 marks ( 3, 4 correct ---- 2 marks ( 2 correct ----- 1 mark (0, 1 correct ----- 0 mark) 3(b) Equation: Al2O3 + 2NaOH + 3H2O 2NaAl(OH)4 (i) 3(b) Equation: Al2O3 + 6HCl 2AlCl3 + 3H2O (ii) 3(c) (i) Equation: 2Sr(NO3)2 2SrO + 4NO2 + O2 3(c) Magnesium nitrate (ii) 3(c) Mg2+ has a higher charge density (iii) Mg2+ polarises / distorts the CO32- anion more strongly / weakens the C—O bond 3 (d) BeSO4 , MgSO4, CaSO4, SrSO4, BaSO4 Total 4 (a) H H H H │ │ │ │ —C—C—C—C— │ │ │ │ Cl Cl
1 1 1 10
3
1 1
2
1 1 1 1
4
1
1 10 1
1
4(b)
2 —CH=CHCl + H2
Equation:
Conditions: catalyst: Ni / Pd / Pt and heat 4 (c) (i)
4
1 1 2
B
A H H │ │ H—C—C—Cl │ │ H Cl
—CH2CH2Cl
H H │ │ H—C—C=O │ H
4(c)(ii) Mechanism: electrophilic addition
1 + 1
1
3
papercollection
4 (d)
2 Br
Br
C
C Cl
CH2Br
Cl
1 + 1
BrH2C H
H mirror
4 (e)
1+ CH3 │
+ 2 CH3—C—Cl ║ O
CH3 │
( 1mark)
CH3 │
1
C—CH3 + ║ O O=C—CH3 (1 mark) + 2HCl (optional) TOTAL
5 (a) (i)
(a) (ii)
2
The standard enthalpy change of atomization of an element is the heat absorbed when one mole of gaseous atoms is formed from the element in its standard state under standard conditions. The standard heat of formation of a substance is defined as the heat evolved or absorbed when one mole of the substance is formed from its elements under standard conditions.
10
1
1 2
papercollection
5 (b) (i)
Born-Haber Cycle Cu2+(g) + O 2-(g)
E (kJ) 2+
Cu (g) + O(g) + 2e ΔHEA ΔHat(O)
st 1
ΔHEA
(O)
nd 2
(O-)
Cu2+(g) + O-(g) + e
8x ½
Cu2+(g) + ½O2(g) + 2e
+ 1
ΔHIE 2nd Cu+(g)
ΔH1st өCuO
Cu+(g) + ½O2 (g) + e ΔHIE 1st Cu(g) Cu(g) + ½O2 (g)
ΔHat Cu(s) Cu(s) + ½O2(g) ΔHfөCuO(s)
CuO(s)
For each enthalpy change correctly shown in diagram above ------------ ½ x 8 = 4 marks Enthalpy diagram with E labeled -------1 mark
5
By Hess’s Law ΔHfө (CuO) = ΔHat ө(Cu) + ΔHIE1stө (Cu) + ΔHIE2ndө (Cu+) + ΔHatө (O) + ΔHEA1stө (O) + ΔHEA2ndө (O-) + ΔHlatө (CuO) -155.2
= (+339.3) + (+750.0) + (+2 000) + (+249) + (-140.0) + (+786.0) + ΔHlatө (CuO)
1
Lattice energy CuO = - 4139.5 kJmol-1
1
Molten- AlCl3 exists as simple covalent molecules. Aqueous- AlCl3 dissociates to form Al3+ / [Al(H2O)6]3+ and Cl- ions
1 1
2 c(i)
2
papercollection
c(ii)
AlCl3 is a covalent molecule. AlF3 is ionic compound Cl- ion is much larger than F- ion Al3+ polarises Cl- ion easily / Al3+ cannot polarise F- easily
1 1 1 1 4
6(a)(i)
pH is negative logarithm to the base 10 of the concentration of H+(aq) ions in mol dm-3 or pH = -lg [H+] (ii) Buffer solution- a solution which resists changes in pH when small amounts of an acid or alkali are added. (b)(i) Ka= [H+][CH3COO-] [CH3COOH] [H+]= [CH3COO-] 1.75 x 10-5 = [H+]2 or [H+] = √ Ka x c 0.100 [H+] = 1.32 x 10-3 pH= -log [H+] = -log (1.32 x 10-3) = 2.88 (ii) pH = pKa + lg [CH3COONa] [CH3COOH] = - lg (1.75 x 10-5) + lg [ (16.4/82.0) ] [ 250/1000 x 0.100 ] = 4.76 + lg ( 0.20 / 0.025) = 4.76 + 0.903 = 5.66 (c)(i) The partition law states that a solute, Q will distribute itself between the two immiscible solvents, ether and water until equilibrium is achieved. At equilibrium the ratio of the concentrations in the two solvents is constant or Concentration of Q in ether = 12.50 Concentration of Q in water (ii) The partition law holds true when the temperature is constant the solute is in the same molecular condition in both solvents / (no dissociation or association) low concentration ( any 2) (iii) Let x= amount of Q extracted by one portion of 25.0 cm3 of ether x / 25.0 ____________ = 12.50 8.00-x/25.0
1
1
1 1
1 1 1
1
1
1 1
1
x= 7.41 g 1 Amount of Q left in aqueous layer = 8.00 – 7.41 = 0.59 g
2
6
papercollection
1st extraction with 12.5 cm3 ether: Let y = amount of Q extracted by first 12.5 cm3 of ether y/ 12.5 ____________
= 12.50
8.00-y/25.0 Therefore amount extracted is 6.90 g 1 The amount of Q left in aqueous layer after first extraction is 8.00g – 6.90g = 1.10 g 2nd extraction with 12.5 cm3 of ether. Let z= amount of Q extracted by the 2nd portion of 12.5 cm3 of ether. z / 12.5 ____________
=
12.50
1.10 – z / 25.0 z = 0.95 g Hence amount left in aqueous layer =1.10 – 0.95 = 0.15 g
Q7 (a)
Mr
1 1 15
Total = ( m x R x T ) / pV = 0.500 x 8.31 x 473 1 1.00 x 105 x 73.6 x 10-6 = 267 1 covalent bond – anyone labelled correct shape ---- 1 Cl Cl: Cl 2 types of bonds 1+ 1 Al Al labelled ----- 1 Cl :Cl Cl coordinate bonding / dative bonding (both labelled)
7 (b)
max 4 marks
4
Aqueous solution of aluminium sulphate contains [Al(H2O)6]3+ / 1 hexaaqua aluminium ion This ion undergoes hydrolysis to produce H+ / H3O+ ions which 1 makes the solution acidic with a pH of 4.8. 1 Equation: Al(H2O)63+ + H2O [Al(H2O)5OH]2+ + H3O+ 3
7 (c)
Carbon dioxide - simple molecular structure with weak van der waals forces between molecules SiO2 has a macromolecular structure/ has a giant covalent structure with strong Si-O covalent bonds
1 1
papercollection
8 (a) (i)
(a) (ii)
(b)
CO2 dissolves slightly in water to produce carbonic acid or CO2 + H2O → H2CO3 Both CCl4 and SiCl4 are simple non-polar molecules CCl4 and SiCl4 are liquids, CO2 is gas because:the intermolecular forces in CCl4 or SiCl4 are stronger than in CO2 due to larger molecular size SiCl4 can be hydrolysed by water but CCl4 cannot Si has empty valence 3d orbitals to accept lone pairs of electrons to form dative bonds with water molecules Carbon has no 3d orbitals / no empty valence orbitals All the three halides react with aqueous silver nitrate to form precipitates / insoluble silver salts or Ag+ + X- → AgX AgCl is white, AgBr is cream/light yellow and AgI is yellow With aqueous ammonia, AgCl dissolves Ag+ + 2NH3 → Ag(NH3)2+ AgBr and AgI are insoluble in aqueous ammonia
1 1 1 1 1 8 1
1 1 1 1 1 5
X + H2SO4 → HX + HSO4 For Cl-, white fumes of HCl gas is evolved
1 1
For Br- white fumes of HBr and brown fumes of Br2 evolved For I-, purple (violet) vapour of I2 are evolved (equation for oxidation of HBr or HI to Br2 or I2)
1 1 1
is an element that forms at least a stable ion that has partially filled d-orbitals
1
-
-
Any two properties below (must give correct examples) green colour of aqueous Fe2+ / yellow colour of aqueous Fe3+ catalytic activity of Fe2+ / Fe3+ in the reaction between I- and S2O82- / Fe is a catalyst in the Haber process variable oxidation states +2 , +3, +6 (any 2) complex formation example [Fe(CN)6]3- / FeO42-
max 4
1+1
3 (c)
Blue precipitate of Cu(OH)2 is formed or Cu2+ + 2OH- → Cu(OH)2(s)
1
blue precipitate dissolves in excess ammonia to form a dark blue solution (complex) - [Cu(NH3)4]2+ or Cu(OH)2(s) + 4NH3 (aq) → [Cu(NH3)4]2+(aq) + 2OH- (aq) When EDTA is now added, the dark blue solution becomes lighter blue due to the formation of [Cu(EDTA)]2- complex or
1
papercollection
[Cu(NH3)4]2+ + [EDTA)]4- → [Cu(EDTA)]2- + 4NH3
1
3 15
9 (a) (i)
4-methylphenol dissolves in NaOH(aq) to form a soluble salt CH3
(a) (ii)
OH + NaOH
CH3
1
ONa + H2O 1
Phenylmethanol does not dissolve in NaOH(aq) 4-methylphenol decolourises bromine and forms a white precipitate
1 1
3
Br CH3
OH + 2Br2
CH3
OH+ 2 HBr 1 Br
Phenylmethanol – colour of Br2 remains unchanged and there is no white precipitate (b) (i)
1 3 1
C=O CH3 – C – 1
2
1+ 1
2
1
2
O (b) (ii) CH3 – C – CH3
(b) (iii)
CH3 – CH2 –C- H
O O Both R and S are heated with Tollen’s reagent / Fehling’s reagent S - metallic silver (silver mirror) is formed / brick red precipitate of Cu2O obtained and R - no silver mirror or metallic silver / no brick red precipitate
(b) (iv)
1
Cl CH3
C
CH3 (P) 1
Cl
papercollection
Cl
1 2
CH3
(b) (v)
CH2
C
H (Q)
Cl CH3COCH3 + 2KCl + H2O
CH3C(Cl2)CH3 + 2KOH CH3CH2CHCl2 + 2KOH
CH3CH2CHO + 2KCl + H2O
1 1
2 max 9
15 10 (a) (i)
B contains a chiral carbon because optically active A fumes in moist air, thus A has acyl functional group / -C-Cl ║ Structure B Hence, Structure A O H H Cl-C-COOH
1 1
1+1
Cl-C-COCl
CH3
CH3
Reaction of A with NaOH produces H
H
HO-C-COONa
1+1
HO-C-COOH
CH3
(C)
CH3
On acidification, C is obtained. (a) (ii) H + Cl-C-COCl
CH3-CH-CH3
_
OH CH3 CH3 Cl-CH-COOCH-CH3
+H
+
HCl
1+1 8
CH3 ( 1 mark for organic product) (1 mark for equation)
papercollection
(b)(i) Geometrical isomerism (cis-trans isomerism) for L H
1
H C=C 1
CH3O
COOCH2(CH2)3CH3
(cis isomer) H
COOCH2(CH2)3CH3 C=C
CH3O
(ii)
1 H
(trans-isomer ) Reaction of L with an aqueous solution of hot sodium hydroxide O 1 CH3O
CH=CH
C
and O-Na+
(c)
CH3(CH2)3 CH2OH Compound: 1- pentanol Conditions: concentrated sulphuric acid , reflux / heat Total
1 1 1 15
7
Related Documents
Stpm Trial 2009 Che Q&a (n9)
June 2020 5
Stpm Trial 2009 Pengajianperniagaan2 (n9)
June 2020 1
Stpm Trial 2009 Che Pp
June 2020 17
Stpm Trial 2009 Sej1 Q&a (n9)
June 2020 1
Stpm Trial 2009 Maths2 Q&a (n9)
June 2020 4
Stpm Trial 2009 Bio Q&a (n9)
June 2020 2More Documents from "SimPor"
Stpm Trial 2009 Che Q&a Kelantan
June 2020 3
Stpm Trial 2009 Matht&s1 (smi Ipoh)
June 2020 1
Spm Phy1 (kedah)
November 2019 13
Pmr Trial 2009 Math1 Q&a (sabah)
June 2020 1
Stpm Trial 2009 Math T Q&a (samtet, Perak)
June 2020 1