NJC_2008 H2 CM prelim P1

Additional Materials: Multiple Choice Answer Sheet Data Booklet NATIONAL JUNIOR COLLEGE PRELIMINARY EXAMINATIONS 2008 CHEMISTRY 9258/01 Paper 1 Multiple Choice 10 September 2008 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name and index number on the an swer sheet in the spaces provided unless this has been done for you. 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 answer sheet. Read the instructions on the answer sheet very carefully. Each correct answer will score one mark. A mark will not be deducted for the wrong answer. Any rough working should be done in this booklet. You may use a calculator. This question paper consists of 16 printed pages (including this page). 1

Section A For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 Which of the following particles have more neutrons than protons and more electrons than neutrons? A NO2 + B 13CO3 2− C 32S2− D 14N2 + 2 Use of the Data Booklet is relevant to this question. Which one of the following has the most unpaired electrons? A the manganese ion in MnO2 B the ammonium ion in NH4Cl C the nickel metal D the nitride ion in AlN 3 Which of the following electronic configurations represent an element that forms a simple ion with a charge of -2? A 1s2 2s2 2p63s2 B 1s2 2s2 2p63s2 3p4 C 1s2 2s2 2p63s2 3p6 4s2 D 1s2 2s2 2p63s2 3p6 3d4 4s2 4 Which one of the following is planar? A CH3CH=CH2 B HNO3 C BCl4 − D H3O+ 2

5 Two bulbs R and S are connected to a 9 dm3 chamber as shown below. chamber (vacuum) Ar 3 dm3 Ne 4 dm3 PAr = 400 kPa PNe = 200 kPa R S What will be the total pressure in the vessel when the valves are opened at constant temperature? A 600 kPa B 286 kPa C 222 kPa D 125 kPa 6 When 0.20 moles of compound D were strongly heated with a Bunsen flame, 12 dm 3 of gas was collected at room temperature and pressure. Which one of the following compounds could D be? A MgCl2 B MgCO3 C Mg(NO3)2 D Mg(OH)2 7 Given the ΔH o and ΔSo of vapourization of liquid E are +10.0 kJ mol−1 and +37.6 J mol−1 K−1 respectively, the normal boiling point of liquid E is A 240 K B 266 K C 300 K D undeterminable from the data. 3

8 When propane burns in air, carbon dioxide and water will be formed. How many drops of water will be formed if 0.100 mol of carbon dioxide is produced? (Assume one drop of water has a volume of 0.05 cm3 and it contains 1.70 x 1021 water molecules) A