DHS Prelim P1 QP

This question paper consists of 24 printed pages and 0 blank pages. © DHS 2014 [Turn over Name: Index Number: Class: DUNMAN HIGH SCHOOL Preliminary Examination Year 6 H2 CHEMISTRY 9647/01 Paper 1 Multiple Choice 30 September 2014 60 minutes Additional Materials: Optical Mark Sheet Data Booklet INSTRUCTIONS TO CANDIDATES 1 Write your name, index number and class on this question paper. 2 There are forty questions on this paper. Answer all questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Optical Mark Sheet. 3 Each correct answer will score one mark. A mark will not be deducted for a wrong answer. 4 Any rough working should be done in this booklet. 5 You may use a calculator.

2 © DHS 2014 9647/01 [Turn over Section A For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 Use of the Data Booklet is relevant to this question. A car releases 0.46 g of an oxide of nitrogen N xOy in the atmosphere. The gas released occupies a volume of 120 cm3 at room temperature and pressure. What are the values of x and y? A x = 1, y = 1 B x = 1, y = 2 C x = 2, y = 1 D x = 2, y = 4 2 In an aqueous solution, 1 mol of MnO4 – ions oxidises 3 mol of Fe2+ ions. What is the manganese–containing product in this reaction? A Mn2+ B MnO4 2– C Mn3+ D MnO2 3 The successive ionisation energies (IE) of two elements X and Y, are given below: IE / kJ mol–1 1st 2 nd 3 rd 4 th 5 th 6 th 7 th X 786 1580 3230 4360 16000 20000 23600 Y 1310 3390 5320 7450 9500 11660 33604 The compound formed when X and Y combine is most likely to be A XY3 B XY2 C X2Y D XY4 4 Which of the following deviates most from ideal gas behaviour at room temperature and pressure? A oxygen B helium C nitrogen dioxide D fluorine

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© DHS 2 7 On pro A B C D 8 Cu act Wh A B C D 014 n the sole b oduct of the CH3CH CH3CH CH3CC CH3CH urve Y an d tivation ene hich is a po The dis value V The dis value E The dis value V The dis value E basis of bon e following r CH3CH (R H(CH2Cl)CH H(CH3)CHCl Cl(CH3)CH2C H(CH3)CH2C d the valu e ergy for a ga ssible outco stribution of V. stribution of Ea. stribution of V. stribution of Ea. nd energies eaction. (CH3)CH2C bond H–CH2R H–CHR2 H–CR3 Cl–CH2R Cl–CHR2 Cl–CR3 R = alkyl gro H2CH(CH3)C lCH(CH3)CH CH(CH3)CH CH(CH3)CH2 e Ea repre s aseous reac ome if the re f energies w f energies w f energies w f energies w 4 9647/0 s given in t h CH(CH3)CH3 bond R 2 R 2 oup) CH3 H3 H3 2Cl sent the e n ction at 298 eaction take will be given will be given will be given will be given 1 he table bel 3 + Cl2  C d energy / k +420 +401 +390 +338 +339 +330 nergy distri 8 K respectiv es place at n by curve Z n by curve Z n by curve X n by curve X ow, predict 7H15Cl + HC J mol–1 bution of m vely. 288 K? Z and the a Z and the a X and the a X and the a [Tu t the major Cl molecules activation en activation en activation en activation en urn over organic and the nergy by nergy by nergy by nergy by

5 © DHS 2014 9647/01 [Turn over 9 HCN can add to butenone in two ways to form products M and N. CN OH O O CN M Nbutenone HCN conjugate addition HCN direct addition The energy profile for the reaction is shown below. O + HCN starting materials O CN conjugate addition product, N direct addition product, M CN OH energy extent of reaction E3 E1 E2 E4 Which of the following statements is true about this energy profile? A Four possible intermediates are formed during the reaction between butenone and HCN. B At lower temperatures, the formation of M is favoured, while at higher temperatures, N is favoured. C If E 1 ≈ E3, N is re-converted back to butenone as easily as M does. D N is formed more quickly than M.

6 © DHS 2014 9647/01 [Turn over 10 A system containing a nitrogen and hydrogen gas mixture is allowed to reach equilibrium. N 2(g) + 3H2(g) 2NH 3(g) H < 0 At time t, a change is made to the conditions inside the reaction vessel. The changes in concentrations with time of the three compounds in the mixture are represented by the graphs below. Which of the following changes, made at time t, could have given these results? A Temperature is increased. B Volume of the reaction vessel is decreased. C Ammonia is removed from the equilibrium mixture. D Argon is introduced into the reaction vessel at constant volume. H2 N2 NH3 Concentration / mol dm–3 Timet0

7 © DHS 2014 9647/01 [Turn over 11 The molecule of deuterium oxide, otherwise known as ‘heavy water’, consists of an oxygen atom bonded to two atoms of the hydrogen isotope, deuterium, D2 1 . Like water, H2O, pure D2O is weakly ionised. 2D2OD 3O+ + OD– For D2O, we can use the term KD instead of KW. The following graphs show how the values KW of H 2O and KD of D 2O vary with temperature. Which of the following deductions is correct? A The enthalpy change of ionisation for both H 2O and D2O is negative. B The degree of ionisation for D2O is smaller than that for H2O. C Both [OH–] in H2O and [OD–] in D2O decrease with increasing temperature. D The O–D bond is weaker than the O–H bond. 13.0 14.0 15.0 16.0 0 1 02 03 04 05 06 0 pKW or pKD Temperature / C D2O H2O

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