HCI H2 Chem 2013 Prelim P1 QP

This document consists of 14 printed pages. HWA CHONG INSTITUTION C2 Preliminary Examinations Higher 2 CANDIDATE NAME CT GROUP 12S CENTRE NUMBER INDEX NUMBER CHEMISTRY Paper 1 Multiple Choice Additional Materials: Optical Mark Sheet (OMS) Data Booklet 9647/01 25 September 2013 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Complete the information on the optical mark sheet (OMS) as shown below. 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 OMS. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. Write your name Write and shade your NRIC or FIN number Write your CT group 551

2 © Hwa Chong Institution 2013 9647 / 01 / C2 Prelim 2013 Section A For each question there are four possible answers, A, B, C and D. Choose the one you consider to be correct. 1 A mixture containing only aluminium oxide, A l2O3, and copper( I) oxide, Cu 2O, weighs 2.02 g. When heated under a s tream of hydrogen, A l2O3 is unchanged while Cu 2O is reduced to metallic copper and steam. Cu2O(s) + H2(g)  2Cu(s) + H2O(g) If the residue weighs 1.88 g, what is the percentage by mass of Cu2O in the mixture? [Mr : Al2O3, 102.0; Cu2O, 143.0] A 12 % B 55 % C 59 % D 62 % 2 A constituent of wood preservative i s manufactured by heating the ore chromite, FeCr 2O4, with sodium carbonate in air. 4FeCr2O4 + 8Na2CO3 + 7O2  8Na2CrO4 + 2Fe2O3 + 8CO2 What are the changes in oxidation number of chromium and iron in this reaction? Change in oxidation number of chromium Change in oxidation number of iron A +1 0 B +2 0 C +2 +1 D +3 +1 3 Use of the Data Booklet is relevant to this question. Copper and magnesium are metals that are widely used in alloys. Each metal forms many compounds containing an M2+ ion. Which statement concerning the atom and ion of these two elements is correct? A Cu2+ ion has a smaller ionic radius than Mg2+ ion. B Cu atom has a lower first ionization energy than Mg atom. C Cu atom has two more occupied electron shells than Mg2+ ion. D Cu2+ ion has a larger angle of deflection than Mg 2+ ion when both ions are passed through the same electric field. 552

3 © Hwa Chong Institution 2013 9647 / 01 / C2 Prelim 2013 4 Lecithin is an emulsifier that is used in chocolate to give a smooth texture. Which of the following statements about lecithin is correct? A It can form dispersion forces with non-polar molecules present in chocolate. B It can form hydrogen bonds between its ow