962/2JABATAN 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 j awapan poda helalan k"' m yang baru. dan StlSun jawapan anJa mettgiiul tl!Nib berongk4 /lealMloian J(m'apon ando busama bub soo/an ini. Jowapan d/lulis do/am hohaso Mclayu DUJU bahasa 'nggerls. BuA" D{I(a dlbela/Um. Instructions to candidates : Anm·er .u the quut/OIU In S«t/o" A in Ihe spaces provided. All ,"lUI be s/JQwn. FiX numerical 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 on afre3h sheet of pafWr, 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 Untuk kegunaan pemcriksa ( For examiner' s use 1 2 J • -+ 5 6 , 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) CONFIDENTIAL 2 SECTION A [40 mar .. ] Answer all qlltrtinn.<: in Ihis section. 1. The mass spectrum of I-bromo-2-chloropropene, C)H 4 CI Br consists of peaks at mJe of 154, 156, and 158. 962f2 a) (i) If the sample of l-bromo-2-<hloropropanc consists of the hydrogen-I , carbon- 12, chlorine-35. chlorine-3?, bromine-79 and bromine-81 isotopes, give the fonnula of the ions responsible for each of the peaks. [3marks] mJe Ions 154 156 158 CONFIDENTIAL ·ntis question paper is CONFIDENTIAL Wltil the examination is over. CONFIDENTIAL 3 96212 (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 trichloride, 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 •••• • .... • 0000 .. .. . ...... ........ ..... . ...... . ... . .. ............... .. .................... 00 ... ... .. ................................................. ......... ................ ............ ....................................... . CONFIDENTIAL ·This question paper is CONFIDENTIAL until the examioaljon is over. CONFIDENTIAL 4 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 1 O ~ mol d r o ~ 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 ? [1 mark] (iii) Calculate the half-life of the reaction . [2 marks] 962f2 CONFIDENTIAL ·This question paper is CONFIDENTIAL until the examination is over. CONFlDENTIAL 5 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 . [31 96212 CONfIDENTIAL *This question paper is CONFIDENTJAL Wltil the examination is over. CONFIDENTIAL 6 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 calcium carbonate at about 1800 K. 96212 (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 reacti on between the three tetrachlorides above with water [2marks] · ...... ..... .... .. ...... ............ ............ .. .. ... .... ... .... .......... .. ... .. .... ..... ... .. · ......... ...... ... ........ ..... ......................... .......... ........ ................. .... .. CONFIDENTIAL ·This question paper is CONFIDENTIAL until the examination is over. CONFIDENTIAL 7 ..l . or8MUc compouud x: of1ll0h'U" of 136.9g IUOrl h.n\ tbe following- by 1l1:l'So'So: I I ( AI Dctenni'1C' rhe lnolec\llt1r foron'lf! ofX. l 2: w."u'ks ] ( b i \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 . . . . . .. . ... ,. ...... . . . , . . . , .. ..... . ... ...... ...... _ .. .... ..... ..... . , ..... ...... " 96212 CONFIDENTIAL -This Question paper is CONFIDENTIAL until the examination is over. CONFIDENTIAL 8 (c, \,"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 bromide to tOl"Ul Z which ii .111 io;OOlCf of X 96212 ( i ) Y h.u tOUl' i .. Give: the \tt''Ucfiu-ol fOrlnuln fOI" the i",oJ\lcr that 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 th..."If produce\. c.:uWu dIOXide wbeu healed with couccutnuc:d acidified Ja.JuO.;':' Qj,·c 3l} equation for the ]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 .. .... ... ... . .. -. , . ....••.. . .. . . . . . . .. . . .. . . . . .. . ... . . . . . .. ... .... . .. .. , .. ....... ... .. ... ....... .................. ... .. .... .. ... ... . ..... . .. .. .... . .. .... ....... ........ ... .... ...... .... .... ...... .. ...... ....... .. . CONFIDENTIAL ·This question paper is CONFlDENTIAL until the examination is over. CONFIDENTIAL 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. Relative Molecular Boiling Solubility in Gas Formula pointl'C water Mass, M, I mol drn·' Ammonia NH, 17.0 -33 18 Hydrogen HCI 36.5 -85 23 chloride Carbon CO 2 44.0 -78 0.033 dioxide (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 marks J (b) A galvanic cell consists of a zinc electrode and a hydrogen electrode as shown in the d.iagram below; & voltmeter • e • PI (+) A-. • e LOa Sait bridge • H.., 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 • 962f2 (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 cell is increased ? if the pH of the acid in the hydrogen half [2 marksJ CONFIDENTIAL -This question paper is CONFIDENTIAL until the examination is over. CONFIDENTIAL 10 6. (a) State the Le ClulieUer 's Principle. [2marl<s) (b) Equilibrium I: '\ H,O(g) + C(s) " H, (g) + CO(g) t.H=+ IJlkJ mol" Equilibrium II: \. 2C.o'(aq) + 2W(aq) " Cr,O,'"(aq) + H,O(I) Use the Le ehottUer's to predict and explain the ettect of (i) Increasing pressure in Equilibrium I, (ii) Increasmg the temperature in Equilibrium I, (iii) Increasing concentration aflf' ions in equilibrium 11, [6marks) (c) 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 CONFIDENTIAL -This question paper is CONFIDENTIAL until the examination is over. 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 = +284.6 kJmor' First ionization energy orM = +731.0 kJmor' Second ionization energy orM =- +2073 kJmor' Enthaply ofatomisation ofF = +79.0 kJmor' Electron affmity ofF = -322.0 kJmor' Lattice fonnalioD energy ofMF .. kJmor' Lattice formation energy of MFl D -2260 kJmor l Using the data above, (i) Draw a Born-Haber cycle for the ronnatioD ofMF. (ii) Calculate the enthalpy of formation of MF . [6 marks) [2 marks] (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 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. 96212 [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) CONFIDENTIAL *This question paper is CONFIDENTIAL until the examination is over. CONFIDENTIAL 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. 0 I H,N C,.. C 0" I 0 II C H ~ C -1,N-CH-C- OH II I (YH,)· H,N Oi C _ 011 , , 11 NH2 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 CONFIDENTIAL ·This question paper is CONFIDENTIAL until the examination is over. CONFIDENTIAL 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. 96212 (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] CONFIDENTIAL ·This question paper is CONFIDENTIAL until the examination is over.
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