Stpm Trial 2009 Che Q&a Kelantan

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962/1

JABATAN PELAJARAN KELANTAN JALAN DOKTOR, 15000 KOTA BHARU.

TRIAL EXAMINATION

2009 CHEMISTRY (KIMIA) SIJIL TINGGI PERSEKOLAHAN MALAYSIA (MALAYSJA HIGHER SCHOOL EDVCATlON)

PAPER 1 (KERTAS 1) MULTIPLE-CHOICE (ANEKA PiLlMAN) One hour Ind forty~five minutes (Satu jam empat pulvb tima min it) Instructions to candidates :

DO NOT OPEN THIS BOOKLET UNTIL YOU TOLD TO DO SO

There are fifty questions in this paper. For each question.low suggested answers are given. Choose one correct answer and indicale iJ on the mu/tiple-clwice answer sheet provided. Read the instructions at, the multiple-choice answer sheet very carefully, Answer all questions. Marks will not be deaucledfor wrong answers.

Arabln kepada c:aIOD :

JANGAN BUKA BUKU SOALAN INI SEHINGGA ANDA DmENARKAN BERBUAT DEMIKlAN

Ada lima pulub soaJon do.lam kerlas in;, Bag; setiup soaian, empal cadangan jawapan diberikan. Pilih satu jawopan yang belul dan randolcan jawopan iIU padn helaian jawapan aneka pilihan yang dibekalkan.

Boca arahan pada helalan jawapan ontko pillluJ" ilU dengan reliti. Jawab semua soolan. Marlwh lidal olean dUolak lxlgijawapan yang salah. This qUestiOD paper con,ists of 13 printed pages (Kertu loaran iai terdiri daripada 13 balaman Mrutak)

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-2SECTION A

Four suggested answers labelled A, 0, C and 0 are given/or each question. Choose one

correct a~·er. 1. Glucose (C6HI206) is the most importanillutrient in the Living cell for generating chcmjcal potential energy. How many grams of carbon are in 16.55 g of glucose?

[Relative Atomic Mass: C- 12; 0><16;

H ~ I)

A. 8.000 g B. 6.620 g C. 3.430 g D. 4.578 g 2. Elemental analysis of 8 sample of an ionic compound gave the following results. 2.82 g of sodiwn. 4.35 g of chlorine and 7.83 g of oxygen. What is the empirical

formula oftbe compound? l RAM: Na=23; CI=3S.S; 0=16) A. N.,CIO

B. NaCI,O C. N.CIO D. NaC IO, 3. Which slalcment explains accurately why iodine is 8 solid whereas fluorine is a gas at room tcmpemlurc? A. Iodine molecule is larger than that of fluorine B. The boi ling point of iodine is higher than that of fluorine

C. The covalent bond in iodine is stronger than that of fl uorine D. 'lbe van der Waa1s forces in iodine molecules arc stronger than those in

fluorine molecules 4. Which ofthe following molecules is polar? A. Ammonia

B. Boron ui01uoridc C. Carbon dioxide D. Beryllium chloride

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5. Use partiaJ orbital diagrams to describe bow mixing of atomic orbitals on the centntl .tom leads to lbe bybrid orbital of the methanol, CH,OH A.

I tit I tit I sp'

B·lt It It I sp'

C.

It It I sp

O.

It I t It It It I sp' d

6. Which of the following unil cell does not have all axis .t right angles?

A. Orthorhombic

B. Monoclinic C. Cubic D. Tetragonal 7. In which or the following liquids the particles are held together by Van der W.. ls

forces? A. Silver

B. Sodium chloride C. Water D. Silicone dioxide

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8. The distribution of the kinetic enelSJ of Sa_us molecules at 279 K and 289 K is represented by the Maxwell-Boltzman distribution curve below: 279 K

Number of

289K

molecules

, Kinetic energy Which of the following best explains why the rate of reaction is double when the

temperature is increaserl from 279 K to 289 K? A. The total area under the curve increases two folds B. The average velocity of the molecules increases two folds

C. 10e number of collision between the particles increases two folds D. The number of molecules having energy greater or equal to the activation enelgy, fa, increases by two folds 9. The ~ values for 7jnc and silver are given below; Zra" ~ + 2e - Zn ,AS" + e Ag It can be concluded that

E' - -0.74 V

E' - -H).80 V

A B

silver is a stronger oxidising agent than zinc 202 " is a stronger reducing agent than Ag+

C

silver is the cathode in the electric cell formed from the combination of the two half-celJs silver will reduce Zn 2+ to Zn

D

10. In the elcctrolysis of aqueous sodiwn chloride using a mercury cathode, the Na'" ion instead of the H+ ion is discharged. This is because A

B C D

mercury is a liquid at room conditions sodium is more reactive than hydrogen sodium is above hydrogen in the electrochemical series hydrogen has a high over·voltage at the mercury electrode

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II. Consider the balf-cells below:

Cu'" + e -+ Cu eu1++ e _ Cu'"

E' - +0.52 V

E' - +O.16 V

What is the E· for the reaction : 2Cu· - Cu2 " + Cu A

B

C

o

+0.36 V -0.36 V +0.68 V -0.68 V

12. Consider the following half-cclls :

Fel • + e _ Felih + 2e -+ 2r Sn4 t + 2c _ S04. Cc.l+ + 3e -+ Ce

E' - +0.74 V E' - +0.55 V E'=+O.15 V E' = -2.33 V

It can be concluded that iodine will A

reduce eel... to Ce

B

oxidise Ce to Celt

C

reduce Peh to FeZ+

o

reduce So4+ to Sn2-f.

13. The rate expression for 8 given reaction is:

- d fAJ = k [A] dl

Which of the following statements about the reaction is not correct? A It

is the fttSt order reaction.

B The half-life of the reaction is a constant. C The reaction could be a radioactive decay. D The rate of reaction is independent of the temperature

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14. Consider the reaction: 4NHJ (g) + 70, (g) ~ 4No, (g) + 6H,O(I) Which of the following species in the above reaction appears or disappears the fastest ? A NHJ

B NO, C 0,

D H,O 15. The table below gives the data for the reaction :

I 2 3

I I

A B C D

r n 1 rnoldm-oT

{19 1 moldm-oT

E~mcnt

I I I

0.050 0. 100 0.100

I

+

0.040 0.040 0.080

Relative rate I I 4

I I

rate - k[XI' [YI rate - k[ X I Y l ' rate = k[XJ rate . k[ Y I'

J

16. An B7..eotropic mixture

A

contains the same quantity of each component in the mixture. can only be separated by stearll distillation maintains its composition when subjecu.-d to fractional dist'illation must have a higher boiling point than the boiling points of the respective

B

C

o

components 17. What is meant by an ideal solution?

A

A solution which obeys Raoult's law

B

A solution whose vapour shows ideal behaviour

C D

A solution is fonned accompanied by release of heat energy A solution where the total vapour pressure is equal to the sum of the partial vapour pressure of the individual liquids in the mixture

18. The pH o f an aqueous so lution o f nitric (V) acid is 0.3. Calculate the W

concentration (in mol dm

A

0.3

C

1.3 1.7

D

2.0

o

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ol

)

of the solution.

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19. Kais better measure for the strengths of weak acids as compared to pH because A B C

its its its its

o

value is easier to measure value docs not depend on tempetature vaJue does not depend on the concentration of the acid value is a whole number

20. Consider the following reaction:

X+Y "

'\

2Z

When 8 mixture consisting of 5.0 mo l of X and 3.0 mol ofY is allowed to reach equilibrium. 2.0 mol of Z is fonn. The ~ for the reaction is A

B C D

0.125 0.250 0.267 0.500

2NO,(g)

21.

"

'\

tllI == negative value

N,O. (g)

Which of the following factors is likely to increase the value of Kcfor the above

reaction ? A B C D

Addition of the cataJyst Decreasing temperature Adding more NO, Increasing temperature

x •

22. CH,CH,I __<> _ _'_k_K... CN

Y is A B C D

•

y

CH,COONa CH, CH,COONa CH,CH,COOH CH, CH,CH,cOOH

23. Which of the following alcohol gives 2-methylpropanoic acid when it is ox.idised? A B C D

I·butanol 2· butanol 2.methyl·l·propanol 2·methyl.2·propanol

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24. Which of the following comoounds does not Rive a yellow DreciDitate with alkaline ·odin , e.? A

Ethanol Ethanai Methno81

B

C D

Phenylethanone

25.

II, (g)

~

6 H ~ + 436 kJ 6H= + 194 kJ 6H= -104 kJ

2H (g)

BI'l (8) ~ 2Br (g) H,(g) + Br, (g) ~ 2fIBr(g)

Use the above data to determine Mi for the following reaction. !i(g) + Br(g) - HBr(g) A B C

o

-288 kJ -367 kJ +263 kJ +526 kJ

26.The enthalpy data for sodium, bromine and sodium bromide are as follows: EnthaJpy of atomisation of Na - + 108 kJ mor l Enthalpy ofatomisation ofBr = +112 kJ mor l First ionisation energy ofNa = +496 kJ mor l Enthalpy of formation ofNaBr = -361 kJ mor' r~ ~ ,~. -3~ ~j ... What is the enthalpy change for the reaction? NaBr (5) ~ No' (g) + Br· (g)

4-"\ ,a..

A B C

o

•

.r

-331 kj mol -752kJmol +33 1 kJ mol +752 kJ rnol

27.Which of the following equations represent the standard enthalpy of atomisation for

iodine? A

I , (g) -21 (g)

B C

Y, I (g) -I(S) y, I, (5) -I (g) 1(5) -1(g)

o

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28. R is a second period element with a valence electronic configuration ofns1np", Which of the following is Dot a compound ofR?

A. RF, B. Na,R C. RCI, D. H,R

29. Compared 10 barium, beryllium is 8 stronger reducing agent B. forms a more basic oxide. C. reacts more vigorously with water. D. fonns more covalent compoWKis.

A.

30. Which of the following stalements is true aboUI NoCI and NaI? A.

NoI is less volatile than NoCI. B. r has a higher chargc density than cr. C. Nal is a stronger red ucing agent than NaC!. D. NoCI and Nal arc both while solids.

31. The following oxides are amphoteric esc.ept

A. AhO, B. PhO, C. SnO D. SiD, 32. The following is true of nitric acid ucept

It can OXI'd'.l.Ze FC,.{-V to Fe:l<- (eq). B. It is used to produce explosives C. It lurns slightly brown wilen exposed 10 IighL D. A mixture of nil ric acid and water is an azeotrope with a minimum boiling point A.

33. Which of me following block--d elements does not show general characteristics of a

transition element?

Scandium B. Vanadium C. Copper D. Nickel A.

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34. Which of the series of oxides shows increasing melting point?

A. B. C. D. 35

"h '7

CI,O, • Al,O,. SO,. Sio,. SO,. Al,O,. Sio, • Cho,. SO,. CI,O,. Sio,. AI,O,. Sio,. Al,o,. Cho,. So,. \\ hieh of tile' fnllo,",ing in nq\l~ous solution of equa l COnCf'll lrnTioll<; A

ChlolT'lelil:III{lil- :Icid

B ('

Dichloroellmlloic llcid Elhanoic ncid

[)

PIK'llI.... '

Whid, of the fo llowinf! jc; formed whe n

l1'ICl hylnllIi nc.('1 hN~b j"

It:!.;

the lo\\ocsl I)H1

tr('ated wit h e)'('t" <;<;

in
A

(CH",NII

C

(C H,),NIIr

B

(C'I-hhN

D

(CI-h,/Nr

What b CH IO

th~

formula


",r Ilk' prO!..hll

o

,

IOfllll'd wht>n .1 compoun\J with 11ll" (f\nnu l.t

NH:: re.ll'I S wllh t',h;mo)khlorlde "l

A

CH,Q@NHC'OC'H,

B

CH ,CO CH ' WH, NH,

C

CH,Q

C

38. Astatine is an element in Group 17 orthe Periodic Table. What are the expected properties of astatine at 25' C?

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39. Phenylamine is a weaker bnse than ammonia because A B

e D

ammonia is an ionic compOlmd while phenyl amine is a covalent compound the lone pair electrons in phenylamine can be delocalized into the benzene ring. ammonia is soluble in water while phenylamine is not. the large phenyl group in phenylamine hinders the attacks by H,O'

40. Which oflhe following statements is true of 21ass? It consists ofwell-ananged silicate Wlits. B. It withstands the aetion of strong alkaline. C. It softens at a wide range oftempetBlures. D. It can be coloured by arlding soda lirn<' A.

Secti•• B

For el/Ch oflhe queslions in this section one or more oflhe Ihree numbered slolements 1/0 3 may be cornCI. Delumin£ which oflhe statements is carree/. The responses A 10 0 should be selected on the basis ofthe following. B

A 1 onI Y is correct

I and 2 only are correct

C 2 and 3 only are correct

D l 1,2 and 3 are correct

4 1. The mass spectrum of an element X is shown below

Yo abundance

100

99.63

0.37 I

Massi charge 14

It can be concluded

15

(m /e)

tha~

t X has two isotopes of relative isotopic mass of 14 and 15 proton 2 The nucleon number of X is 14.5 3 The isotopes of X have different number of protons.

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42. Which of the following statements is true of electrons occupying an atom? 1 Electrons occupy orbitals based on the Aufbau Principle. 2 Each orbital can contain a maximum of two electrons. J The two electrons in an orbital have opposite spin

43. The quantity of substances produced during electrolysis depends on J

2 3

the magninlde oflhe current temperature the concentration of the aqueous ion

44. Which oflhe following solutions wilJ produce hydrogen gas when eJectrotysed using

platinum electrodes ? 1. dilute sodium hydroxide

2. dilute sodium cbloride 3. dilute hydrochloric acid 45. During the anodisation of aluminium I. oxygen is liberated at the aluminium electrode 2. the electrolyte used is an aqueous solution ofaJuminium sulphate 3. aluminium is made the cathode 46. The following graph shows the energy profile for the reaction: P

';!

Q

Energy • •• • • •

•• • • •

• ••

• ••••••• •••••••• •••••

E,

reaction pathway Which of the foUowioe. are true ? 1 The activation of the reverse reaction is Ez 2 The enthaJpy change of reaction is E1 - ~ 3 Addition of a catalyst can aJler the value of E. llDd E::z

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47. The mte equation for the reaction: A + B - products, is

The value of k depends on

I . catalyst 2. the values ofx and y 3. the concentration of A and B 48. Which of the following compounds will react with ethanoyl chloride? I Water 2 Phcnylamine 3 Propanal 49. Which of the following arc characteristic of the benzene molecule? I. It is planar 2. It undergoes electrophilic substitution reaction 3. All the carbon a10m undergoes Sp2 bybridisation 50. Which of the following molecules have polar bond but have no overal l dipoles ?

I CI, 2 C,H, 3 'BeCl,

THE END OF QUESTION PAPER

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962/2 JABATAN PELAJARAN KELANTAN JALAN DOKTOR, 15000 KOTA BHARU.

TRIAL EXAMINA TlON

2009 CHEMISTRY (KIMlA) SIJIL TlNGGI PERSEKOLAHAN MALAYSIA (MALAYSIA HIGHER SCHOOL EDUCATION)

PAPER 2 (KERT AS 2) Two aod I bllf bour (Duo jam . ... ngab ) DO NOT OPEN TlDS BOOKLET UNTIL YOU TOLD TO DO SO Arahan kepada calon : Jawab $(!JfUlII soaJan da/am <aglllif A d%m l'1Iong yang disl!diaJtan. Setnua ierja mesliJd ditunj uU(l'1. Bag; jawapan MrangAa. unit mrstllah dinyolakon manu-mana yang suuoi. Jawab mono-mana myHIt Soa/on daripada Bda,liIlI B. Unluk bohogian inf, ,ulis jawopon andu poda he/aian Jawupon yang dibellI/ion. Mllldkan·sellap jawapan poda helalan k"'m yang baru.

Untuk kegunaan pemcriksa ( For examiner's use~ 1

2 J

dan StlSun jawapan anJa mettgiiul tl!Nib berongk4 /lealMloian J(m'apon ando busama bub soo/an ini. Jowapan boI~h d/lulis do/am hohaso Mclayu DUJU bahasa 'nggerls.

•

BuA" D{I(a dlbela/Um.

5

Instructions to candidates :

6

Anm·er .u the quut/OIU In S«t/o" A in Ihe spaces provided. All ~'Of'king ,"lUI be s/JQwn. FiX numerical (J~'en. units IffJIst ~ quoted Vo'hUffVU they (ll'e approprlUlL An,wv any fo,,, quesliOlU from Section IJ. For Ihis section, wr/le your answers on Ihe answer shuts provided Begin eoclr ~'er on afre3h sheet ofpafWr, and arrange your QtJ.nI.·crs in numerical ordu. Tie YOIII' atJ.nl.'t'I" sheets to Ihu booAlel, Answers may be y.'rinen In eillwr Malay or English. A Doto lJoojjet is provided

-+

, 8 9

+

10

Jumlab

l..m>t!!ll This question paper consists of 13 printed pages (KertaJ sollan iui ferdin dllnpada 13 hal.man bercetak)

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SECTION A [40 mar..] Answer all

qlltrtinn.<:

in Ihis section.

1. The mass spectrum of I-bromo-2-chloropropene, C)H4 CI Br consists of peaks at mJe of 154, 156, and 158. a) (i) If the sample of l-bromo-2-
mJe

Ions

154

156

158

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(ii) If the ratio of chlorine-35 10 chJorine-37 is 3: I and bromine-7910 bromine-81 is I : I calculate the relative abundance of the peaks. [3marks]

mle

Relative abundance

154

156

158

b) Phosphorus is an element of group 15. PhosphOrus react W1ln Chlonne to lorm phosphorus trich loride, PCI, and phosphorus pcntachloride, PCI,.

(i) Write the electronic configuration afthe phosphorus atom.

[I mark]

·....................................... ... ... ............................... ..................

'

(ii) Stale the typc ofhybridisalion in PCI, and PCI, [I mark] •• • •••• • • ••• •••••• •••• •• • • •• ••••••••• •• • •• ••••• •••• •••••• •• • •••••••••••••••• •• •••• ••• ••••••••••

(iii) Suggest wbethcr nitrogen will form a pcllthachloridc, Nels. Explain your

answer.

[2mark]

·... ............. ..... .... ... .. ...... ... ...... .. ... . ... ...................................... . • ••••• •• ••• •• • •• •• • ••• • • • • • • • • • • • • • • • • • • • • • • • • •• ••

, ~

•

••• •• • • •• •••••• ••••••••••••• ••••• • 0 0 ••••

• . . . . • 0 0 0 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 . . . . . . . .

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2. The decomposition ofbydrogcn peroxide is a fir.Jl order reaction.

2H,o, (oq) - 2H,O (I) + 0, (g) (8) Explain what is meant by order o/reaction ? ... ... -........ ... ...................... ,

[2marks]

.... ............................................... .. ..... .

. .. ........... ................ ......................... ................. ... .............. ........... (b) Write the rate equation for the decomposition of hydrogen peroxide.

(1 mark)

•••••• ••• • ••••••••••••• • ••••••••• • •••••••• ••••••••••••••••• • ••••• •••• ••• ••••••• ••• •••••• •• •••••• •••

(c) The rate constant for the reaction at 298K is 3.42 x 1O~ mol

dro~ SO' •

(i) Calculate the rate of decomposition of hydrogen iX'iOKide when the concentration is 1.25 x 10-' mol dro-l [1 mark]

:ii)

~t

is the rate of production of oxygen at the same instant ?

(iii) Calculate the half-life of the reaction .

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[1 mark]

[2 marks]

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c) Sketch a graph to show the variation of the concentration of hydrogen peroxide with time. You may assume that the initial concentration of hydrogen peroxide

is t .O mol dm°l

.

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3. An important use of silicon compounds is to make glass. The simplest fonn of glass is soda glass which is produced by melting silica (Sio,), sodium carbonate and calc ium carbonate at about 1800 K. (a) Name a subslance which can be added to soda glass in order to (i) increase its melting point.

[I mark]

• •••••• • •• • • • ••••••••••••••••• ••• •••••••••••••••••••• • •••••• • •••••••• • ••••••••••••••

(ii) give a coloured product.

[I rom]

................ , ... .... ............... ..... ...... ... ....... ......... .. ........ .. ......... ... (b) Give a difference in terms of bonding and structure between glass and ionic

crystal.

[2marlcsJ

... ......................... .................... .......... .... ... ... ....... .. ...... - .............. . ........ .. .................................... .. ..................................... ............... ••••••••••••••••••• • •• • ••••••• • • • ••••••••••••••••••••• ••• ••••• • ••• • •• • • •• •• •••••• ••• • • •• • • •••• •• ••

(c) Group 14 clements can react with chlorine to fonn a tetrachloride. i) In the following table, give the name of the process (if any) and the equation of the reaction which occurs.

[4marlcs]

ii) Explain the differences of the reaction between the three tetrachlorides above with

water

[2marks]

·...... ..... .... ........ ............ ............ .. ..... .... ... .... .......... .. ... .. .... ..... ... ..

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..l .

7

.~ or8MUc compouud cOlul'o~itiou

x: of1ll0h'U" Ula~~ of 136.9g IUOrl

h.n\ tbe following-

by 1l1:l'So'So:

I ( AI

I

Dctenni'1C' rhe lnolec\llt1 r foron'lf! ofX.

l

(b i

2: w."u'ks ] \Vbcu X is boiled under n::flux with aqueous ,,"odium hydroxide. 2.mcthyl·l· prop:''lUol is formed . ( i)

DJ'OW the su 'ucnu'nl fOl"llluln of X

( u)

Srmc the meCh:lul'illl of the I'cnetion .

.... .. . ...

,.

......

... , .. .

,

.. ..... . ... ...... ...... _...... ..... ..... ., ..... ......

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\,"hen X ii lI'c:afcd with:m olc:oholic ioluriou of sodium hycb·oxide. :\11 olkcuc Y ii fonncd. Y 1"C,'Ch with hYcU'o~cn bromide to tOl"Ul Z which ii .111 io;OOlCf of X ( i)

Y h.u tOUl' i .. ome~ . Give: the \tt''Ucfiu-ol fOrlnuln exhibih ilcom,ctric:d is.omcTiwl

( u)

Dl":1w tbe 'iotJ"\lcmrRI tOJ"1\lu!n for Z

( iii)

5!r:nc oue i'JOlUer of Alkene Y

fOI"

the i",oJ\lcr that

produce\. c.:uWu dIOXide wbeu healed with couccutnuc:d acidified Ja.JuO.;':' Qj,·c 3l} equation for the 1~.1CfIO ll. th..."If

]somt>I""

\d)

Z renct\. with .1que-om \odilUU hydroX1de 10 fOl'll1 AU alcohol P SU,i:g:cst (1 .. uuple chClmC31 Ie .. ' 10 diifcl'cnri :nc Ixtwccn 31cohol P 2-lllcthyl. J -pl'op:mol

~md

... ... ... -. , . ....••.. . .. ... ... .. . ... ... ... . ... ..... .. ... .... . .. .. .. ....... ... .. ... ....... .................. ... .. .... .. ... ... ...... ... ...... . .. .... ....... ........ ... .... ...... .... .... ...... .. ...... ....... .. . .. .... ,

96212 ·This question paper is CONFlDENTIAL until the examination is over.

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9 SECfION B [60 marko]

Answer any four queslions in this section.

5(0) The boiling points and solubilities of ammonia, hydrogen chloride and carbon dioxide gases are given in the table below.

Gas

Relative Molecular

Formula

Ammonia Hydrogen chloride Carbon dioxide

Boiling pointl'C

Mass, M,

Solubility in water I mol drn·'

NH,

17.0

-33

18

HCI

36.5

-85

23

CO2

44.0

-78

0.033

(i) Explain the variation in the boiling points and solubilities of the gases relating to

bonding.

[5 marks]

(ii) Ammonia dissolves in water to produce ammonium ion. Draw the Lewis structure and predict the shape of ammonium ion. [3 marksJ

(b) A galvanic cell consists of a zinc electrode and a hydrogen electrode as shown in the d.iagram below;

&

e• PI(+) H.., • LOa

A-.

voltmeter •

e•

Sait bridge

Zn(-)

H' (aq)

:: ~J~L::: _~:: -------------.- .

----------------

--

--------

------------------------- - ------------ ----

--

ZnSO.(i.O mol drn-') at 298 K

In experiment. the emf of the cell is found to be +0.54 V at 25°C. The pressure of the hydrogen gas is 1.0 atm and the concentration of zinc sulphate is l.O mol dm·J•

(i) Calculate the concentration of the W ion in the hydrogen half cell. [5 marks] (ii) What is the effect on the emf of the cell if the pH of the acid in the hydrogen half cell is increased ? [2 marksJ 962f2 -This question paper is CONFIDENTIAL until the examination is over.

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6. (a) (b)

10

State the Le ClulieUer 's Principle.

Equilibrium I: '\ H,O(g) + C(s) "

H, (g) + CO(g)

Equilibrium II:

\.

2C.o'(aq) + 2W(aq) "

[2marl<s) t.H=+ IJlkJ mol"

Cr,O,'"(aq) + H,O(I)

Use the Le ehottUer's to predict and explain the ettect of

(c)

(i)

Increasing pressure in Equilibrium I,

(ii)

Increasmg the temperature in Equilibrium I,

(iii)

Increasing concentration aflf' ions in equilibrium 11,

[6marks)

The Contact process is important in producing sulpburic acid. 2So,(g) + o,(g)

2So,(g)

t.H~

- 197kJ mol"

When suJphur dioxide and oxygen in the ratio of2: I at an initia1 tota! pressure of 3 atm are passed over calalyst at 430·C, the partial press,,", of sulphur trioxide is 1.9 atm.

(i)

Calculate the partial pressure of So, and 0, at equilibrium, the tolal pressure at equilibrium and the percentage ofSCh that is convened to SO).

(ii}

Write an ex'pression for the eqwHbrium constant, Kp, and calculate its value. [7marksl

962/2 -This question paper is CONFIDENTIAL until the examination is over.

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CONFlDENTW.

II

7. (a) Define the standard fonnation and lattice energy of sodium chloride crysta1line. [4 marks] (b) The possible fluorides formed by an clement M are MF and MF, EntbaplyofatomisationofM First ionization energy orM

Second ionization energy orM Enthaply ofatomisation ofF Electron affmity ofF

= +284.6 kJmor'

+731.0 kJmor' =- +2073 kJmor' = +79.0 kJmor'

=

= -322.0 kJmor' Lattice fonnalioD energy ofMF .. ~969.0 kJmor'

Lattice formation energy of MFl

D

-2260 kJmor l

Using the data above, (i) Draw a Born-Haber cycle for the ronnatioD ofMF.

[6 marks) [2 marks]

(ii) Calculate the enthalpy of formation of MF .

(iii) If the enthalpy of formation ofMF, is + 342.6kJmor', which compound will most probably be formed when M reacts with F. [3 marks)

8. (3) What is meant by a transition clement?

[I mark]

(b) Transition clement complexes are often coloured whereas compounds of other meWs are usually white. For example, a solution of [Cu(H20~]2+ complex ion is

blue but a solution of [Cueh]" complex ion is colourless. Explain these

observations in terms of electronic configurations.

[5 marks]

(c) (i) Carbon, silicon, germanium, tin and lead are elements in Group 14 of the Periodic Table. Describe the variation in acid·basc character of their oxides. [5 marks] (ii) Lead (TV) oxide is a dark-brown solid. When lead (IV) oxide is healed with an aqueous solution of a manganese (II) salt in the presence of excess nitric (V) acid, the

reaction that takes place is as follows. 2Mn'· + 4H+ + 5PbO,

-

2MnO' + 5Pb>+

+ 2H, O

Explain how lead (IV) oxide reacts. and state what is observed. [4 marks)

96212 *This question paper is CONFIDENTIAL until the examination is over.

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12

9 Give an explanation for the foUowing observations to identify the compounds orG, J, K.L. M and N and write the cbemicaJ equation involved.

(a) The chlorine atom in compound G (C,H,cI) can be replaced readily as a result of reacljon with dilute aqueous sodium hydroxide. However. the chlorine atom in isomer J is not affected by the above reaction. [5 marks] (b) If oompound K (C.H,N) is """ted first with bromine and then ethanoyl chloride , oompound L (C.HoBr;NO) is obtained. IfK is treated firsl with ethanoyl cbloride and then followed by bromine, oompound M (CaH.BrNO) is the product. [5 marks]

(c) Compound N (c..HIOO). can exist as a pair of optical isomers and reacts with phosphorous pcnlachloride to give hydrogen chloride.

[5 marks]

10. The amino acid tyrosine, lysine and glycine are constituents of many proteins.

H,N

C,..

I

0 I C

0" 0

II

CH~

-1,N-CH-C -

C

OH

I (YH,)·

H,N

NH2

Oi

,,

IIC

_ 011

11

OH tymsine

lysine

glycine

a) State the reagents and conditions you could use to break proteins down into amino acids. [2marks]

b) Draw a nnR around each chiraJ centre in the above molecuJes. [2 marks] c) In aqueous solution amino acids exist as zwiuerions. Draw the zwitteronic structure of glycine. [I mark]

96212 ·This question paper is CONFIDENTIAL until the examination is over.

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13

d) For each of the following reactions, draw the structure oftbe organic compound fonned. (i)

glycine + excess NaOH(aq).

(ii)

tyrosine + excess NaOH(aq)

(iii)

lysine + excess HCI(aq)

(iV)

tyrosine + excess Br,(aq)

[5marksl

e) Draw the structuml formula of a tripeptide formed from aU three of these ruTtino acids, showing clearly peptide bonds. [2 marks)

I) The formula of pan of chain of a synthetic polyamide is shown below.

(i)

Identify the repeat unit of polymer by drawing square brackets around it

on the above formula. (ii)'

Draw the structure of two monomers from which the polymer couJd be

made. (iii)

Name the type ofpolymeri7.ation of polymer shown above.

[3 marks]

96212 ·This question paper is CONFIDENTIAL until the examination is over.

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Answer 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.

B D D A A B C D C D A B D C D C A D C D B B C C B

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.

D C A D C D D A C B D A A B C A D A D A D A B D C

,

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STPM Trial exam2009 PAPER 2 Kelantan SECfIONA I.

(a)

(i)

mi.

Ions

154

C H,"CI" Br ,C, H,"sr"CI+

156

c,Hl ' CI"Br, C,H}'Br"C I+

I

c,Hl'CI" Br, C, H. " Br"CI +

c)Hl7CI8I Br""

158

C, H. " Br"CI' (1 + 1+ 1]

(ii) Relative abundance

mi.

"CI"sr : (3x l)2 ~ 6 or 3

154

~Br : (3x l )2 ~ 6 156

"CI" Br : (lx l )2 - 18

158

or 4

"CI" Br : ( lxl)2 ~ 2 or I [1 + 1+ 1]

(b)

(i) (ii) (iii)

(I]

I,' 2,' 2p' 3,' 3p'

PCI, - ,p' and PCI,- , p' d Nitrogen cannot form a penthachloride, Nels because nitrogen do not have d orbital.

(1 + I] [I +I] Total 11 Muimum 10

2. (a) The power to which the concentration of a substance is raised in an experimentally determined the rate equation .

[2J

(b) Rate ~ k[H,O,] (I]

(c)(i) Rate ~ (3.42 X 10·' X 1.25 X 10.2 ) <= 4.28 x IO,Smol dm') s·] (ii) Rate ~

[I]

1', x (4.28 x 10·')

= 2.14 x IO,S mol dm') 5. 1

[I]

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(e)

Halflife ~

In 2

[I]

k 0.693 - 3.42xI 0·) - 202.6 s

[ I)

(f)

[H,o,) moldm-) 1.0

0.5

0.25 •• •

••• •

Time I s

Total 3.

(a) (i) Boron oxide (ii) Nickel oxide

10

[I )

[I) [I)

(b) In glass, there is no regular arrangement of particles. The arrangement is just like in liquid. However, in crystalline ionic solids, the ions are arranged in an ordered and clole;ly·oacked manner.

(e)

ill

[11

(i)

PbCI. + [4) (ii) SiC~ and PbC~ have empty d orbitals which are snacked by lone pair electrons of water molecules. But in eeL.. the carbon atom does not contain d orbitals. [ 1+ 1]

Total:

10

... . 4

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(a) C 135.2112 = 2.9

No . of moles II Mole .. tio 4 Molar mass : 136.9 Molecular fonnu la : C.H,Br

:!:@ I (i)

Br I 58.3/80 = 0.73

H I 6.5/1 = 6.5 9

1m

1

lUI

I

I

.. . I

CH, 1m

I CH, - CH - CH,B,

(U) (e)

Nucleophilic substitution SN2 (primary haloi:t'n alkanes)

1m

(Q

H H I I CH.J - C = C- CH, or CH, CH = CHCH,

1m

(n)

CH,

I

1m

CH, - C - CH,

I (iU)

I SOMer.

Br CH) CH2 - CH "" CH2 or CH,- C - CH,

1m

I

CH, EquIJrlo,. : CH, CH, - CH - CFh + 5(OJ Or C(CH,lFCH, + 4[0]

(d)

•

CH, CH2 - COOH +C0z+ HP (CH,),C-o + CO, + H2O

lID

-Wann wit h aqueous acidified KMnO •. .Alcohol P does oot decolourisc the purple solution. -2-metbyl- l- propanol decolour1ses the purpk solution. (oxidation of LE ' alcohols

1m

•

1m 10m

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SECTION B

5(a)(i)

NH,

[I + I]

bonds between

>

reac~

dcr Waals forces

HCI

or

HCI + H,O 7 H,O' +

between Co, molecules are

cr [1 +1+ 1]

stronger than van der

are non

Waals forces between whereas water molecules are HCI molecules polar

co,

-

+

H

H 'til H H

(a)(ii)

N 4H

5e 4e

Charge + 1

~

[I]

8e ~ 4 bondi ng pair.;

[I] [I]

Shape : Tetrahedron

[I]

5(c) (i) Zn(s) +. 2W(aq) 7 Zn" (aq) + H,(g)

[zn '- ]?

-

E' 0.059 I "" - 2 og

+1).54

=

(0-(-0.76» _ 0.059 10 1.0%1.0 2 g [W]'

+0.54

=

+0.76 + 0.059 x 2

H ,

[I]

[H ' ]'

[ I]

210g[W] [I]

log [H1 = -3.73 pH - -log [H'] - 3.73

[I]

(ii) If the pH of acid increases, IWI decreases emf of the cell decreases

[I] [I]

-

1

Total

IS

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5

6.(a) Le Chlltelier 's principle states that if a system in eq uilibrium is disturbed, the equilibrium will shift to ca.Dcel out the effect of the change. [2) (b) (i) Increasing the pressu", will couse the equilibriwn shift to the left because the foward reaction involves an increase in the number ormolcs of gas. or I mol? 2 mol (ii)

The reaction to the ripht is endothermic.

[I] [I] [I]

Thus heating will cause the equilibrium position til move to the right.

[IJ

The equilibrium will shift to the right because more cr04 ' ions react with W ions to produce CC20," and H20. Thus the concentration of W ions can be reduced.

r1]

(iii)

(c) (i)

Total gas ratio - 2+ I =3 Initial paroal press"", of So, = 2/3 x J = 2 atm Initial partial press"", of 0, - 113 x J - I atm

[I]

[I]

2So,(g) + O,(g) +:! 2S0,(g) 1.9atm From the equation above, to produce 1.9 atm o[SO), 1.9 aIm S02 and 0.95 atm 0[02 must react.

Psm = 2 - 1.9 - 0.1 atm Po, = I - 0.95 - 0.05 atm

[I] [I)

PSOl + POl + POOl = 0.1 + 0.05 + 1.9 = 2.05 atm Percentage of cbange from So, to SO, . JQitial pressure of S(h is 2 atm. 1.9 atm of S02 has reacted to become SOJ. Therefore, percentage of change - 1.9 / 2.0 x 100 - 95% PlOW ""

(ii)

2S0,(g) + 0, Kp

=

~

[I]

[I]

• 2S0, (g)

(P~) (Pm)

[I)

- iH;'(OO5) = 7220 atm-!

[I]

7

Total:

15

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6

7 (a) 0) The enthalpy change when one mole of an ionic compound is fonned from its element, al standard condition. [I J

Na (,) +

1

2" Ch (J)- NaCI (,) [I + IJ

(ii) The energy released when one mole of an ionic comoound is fonned from its gaseous ion at standard condition.

[lJ [I + IJ

(b) (i)

-969.0 - - -'O!MF W

M

+731.0

·322.0

+284.6

+79.0

(s)

+

[5J (ii)

6 H((MF) = + 284.6 + 731.0 + 79.0 - 322.0 - 969.0 6 H((MF)

(iii)

=

[lJ [lJ

-196.4 icJmor'

MF because its enthalpy of fannalian is more exothermic. This shows that MF is more stable since its enthaJpy is lower. [2J Total:

IS

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8.(a) Transition elements are defined as d-block elements that can form at least one stable ion with partially-filled d orbital. [I] 3d

(b) Cu' in [CuC],]"

CU"in[Cu(H,Ol6]"

11~11~11jj 1~11~1 11~11v110101

4s

Q

[I]

I 0

[I]

Splitting of the energy of the 3d-orbitals occur. [I] Electrons in the low energy 3d-level of Cu2+ absorbs (red) light and move into the high energy [I] 3d- level. I dod transition occurs. No dod transition occurs. [I]

[I]

(c) (i) The basicity of the oxides increases down the group.

[I] [I + I]

CO is neutral. Si02 and C02 are acidic. Oxides of Ge, Sn and Pb are amphoteric.

[ IJ

(ii) Lead (IV) oxide I PbO, is an oxidizing agent. I Pb4+ is reduced to Pb2+.! +2 oxidation state of lead is more stable than +4 oxidation state. Mn 2+ is oxidized to Mn7+! MnO,,'.! Oxidation state for Mn change from +2 to +7. A redox reaction occurs. Solution turns purple ! violet ! pink at the end of reaction. ! dark-brown solid dissolves. ! solid dissolves. Total:

[IJ [I] [I J

[I]

15

[Notes: Transition complexes are coloured because of electronic transition between non-degenerate d orbitals. The transition .(Oetal ions have incomplete 3d sub-shells, d l to d9 . As a result, d-d electronic transition is possible resulting in pair of the visible light spectrum being absorbed. Other non-transition metal ions have either completely filled 3d orbital or no 3d electron at all. Hence, dod electronic transition is not possible, ] they are colourless or white.

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9(a)

In G, the CI atom is bonded to the side chain hence it can be replaced by hydroxide during hydrolysis. Gis

0

o

-CH,CI

[I]

o

+ NaOH 7

CH, CI

[I]

_CH,OH + NaCI

[I]

In J. the Cl atom is attached to the aromatic rin2. The C- CI bond in H is less polar and strong. [I]

J is

or

<0>-

CI

CH, CI

[I]

CI 5 9(b) K is

o

[I]

NH,

With aqueous bromine.

o -NH,

2,4,6-tribromophenylamine is fonned as a white precipitate.

Br

+ 3Br, 7 Br-

o

+ 3HBr

.-NH,

[I]

Br With etbanoyl chloride. a substituted amide is fonned. Sr

Sr

-NH, + CH,COCI 7 B.r(L)

Br

.-NHCOCH, Br

+ HCI

[11

K with ethanoyl chloride

o

NH,

+ CH,COCI 7

NHCOCH, + HCI [I]

With bromine substitution occurs at benzene ring J

o

_NHCOCH,

+ Br, 7 [I ]

•

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9(c)

[I] [I] [I]

N has a chiral center because it exists as a pair of enantiomers. It is an a1 cohol as it reaclS with PCI,: to give He) gas. N is CH, CH(OH)CH,CH, C!i,CH(OH)CH, CH, + PCI, CH,

I

Hif'J

~

CH, CHCICH,CH, + HCI + POC!,

[I]

,, ,, ,,

"'-C H,CH,

[I]

H

Non- superimpossable 5

Total :

9

(a)

He l or H2S0"or H+ .. acid

conc(ifHC I oDlyVdilute/aqueous + heal (b) (e)

(d)

15

1m 1m

two ri.ngs only ( I ring around the (I-C ofryrosinc & I around me (Z-e of lysine) "'NH)CH~~· (or displayed ronnuta) (i) NH2CH2C02. (Ns ~ (either -C0 2"Na"'0' -C02Na but NOT -CO-O-Na)

1m 1m 1m

(ii) (N.,) '-Q-C6H4-CH2CH(NH, )CO'- (No') (iii) (C I)+NH)(CH, ).CH(NH)')CO, H (Cl)

Iw+lm Im+lm

(6m )

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'0

(el 2m CH

•

CO.H

stnktWt [IJ

III least one peptide group identified [I J

(I) (Q(Q.g.

anorOl -01 -

00· 'If" CI\-

CI\- H1!-

3m

[I)

(i) III

III orClCOI---

15m

fll

(iii) Condensation polyrnerisation

TOIaI : 16

Maximum :

15