HCI H2 Chem 2012 Prelim P1 QP

This document consists of 19 printed pages. HWA CHONG INSTITUTION JC2 Preliminary Examinations Higher 2 CANDIDATE NAME CT GROUP 11S CENTRE NUMBER INDEX NUMBER CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 9647/01 21 September 2012 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

2 © Hwa Chong Institution 2012 9647 / 01 / JC2 Prelim 2012 Section A For each question there are four possible answers, A, B, C and D. Choose the one you consider to be correct. 1 When iron is reacted with aqueous iron(III) ions, iron(II) ions are formed. Assuming the reaction goes to completion, how many moles of Fe and of Fe3+(aq) would result in a mixture containing twice the number of moles of Fe 2+(aq) compared to Fe 3+(aq) once the reaction had taken place? moles of Fe moles of Fe3+(aq) A 2 4 B 2 5 C 2 6 D 2 7 2 45 cm3 of 0.8 mol dm−3 of potassium iodide and 30 cm3 of 0.5 mol dm−3 of lead(II) nitrate were mixed together. The equation for the reaction that occurs is as shown. 2KI(aq) + Pb(NO3)2(aq) → PbI2(s) + 2KNO3(aq) What will be the approximate concentration of the iodide io ns in the solution after the reaction has completed? A 0.006 mol dm−3 C 0.133 mol dm−3 B 0.080 mol dm−3 D 0.280 mol dm−3 3 Alpharadin®, containing the radioactive isotope Ra223 88 , is currently under clinical evaluation for the treatment of cancer. Ra223 88 decays to give only an element X and a high energy α-particle ( He4 2 ); the latter targets the cancer cells. Ra223 88  X + He4 2 Which row in the table correctly defines the chemical symbol for element X and the number of neutrons in its nucleus? chemical symbol for element X number of neutrons A Po 135 B Po 219 C Rn 133 D Rn 219

3 © Hwa Chong Institution 2012 9647 / 01 / JC2 Prelim 2012 4 The cylinder in a car engine has a volume of 0.500 dm 3 when the piston is at the bottom of its stroke. At this point the pressure is reduced to 95.0 kPa and the reduced pressure causes the fuel/air mixture to move into the cylinder. At the top of its stroke, the piston has compressed the gases to 25 cm3. Assuming that the temperature in the cylinder remains constant, what is