MJC_H2_CHEM_P1

Reg NumberClass No part of this paper should be repro duced for commercial use without the prior written permission of Meridian Junior College. Candidate Name _____________________________ ©chemistry dept@mjc 1 Meridian Junior College 2009 JC 2 Preliminary Examination H2 Chemistry 9746 24 September 2009 1 hr Paper 1 MULTIPLE CHOICE QUESTIONS Additional Materials Data Booklet INSTRUCTION TO CANDIDATES Write your name, class and r egister number in the spaces provided at the top of this page. There are fourty questions in this section. Answer all questions. For each question, there are four possible answers labeled A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the OMR answer sheet. Read very carefully the instructions on the OMR answer sheet. You are advised to fill in the OMR An swer Sheet as you go along; no additional time will be given for the transfer of answers once the examination has ended. Use of OMR Answer Sheet Ensure you have written your name, class r egister number and class on the OMR Answer Sheet. Use a 2B pencil to sha de your answers on the OMR sheet; erase any mistakes cleanly. Multiple shaded answers to a question will not be accepted. For shading of class register number on the OMR sheet, please follow the given examples: If your register number is 1, then sha de 01 in the index number column. If your register number is 21, then sh ade 21 in the index number column. This question paper consists of 21 printed pages

1 The reaction between silicon tetrabromide, SiBr4, with moist ethoxyethane produces four oxobromides with the formulae SiO2Br8, Si2OBr6, Si3O2Br8 and Si4O3Br10. When 0.192 g of one of the oxobromides was completely reacted with water, all it s bromine was converted into bromide ions and produced 0.392 g of a cream precipitat e when an excess of silver nitrate was added. Which of the following shows the correct identity of the oxobromide which reacted with water? A SiO 2Br8 B Si2OBr6 C Si3O2Br8 D Si4O3Br10 2 Nitrogen oxides are air pol lutants. In a reaction, 0.20 mol of an oxide, NxOy was reacted with 20 dm 3 of hydrogen gas at room temperature and pressure and passed over a heated catalyst to produce ammonia and water as the only products. At the end of the reaction, 0.80 dm 3 of hydrogen gas remained. The ammoni a produced required 0.200 mol of sulphuric acid for complete neutralisation. The reaction of the oxide with hydrogen can be r epresented by the following equation: N xOy (g) + 2 2y 3x H2 (g)  x NH3 (g) + y H2O (l) What is the molecular formula of the oxide? A NO B NO2 C N2O D N2O4 3 In an experiment, H 2S was reacted with 24.00 cm 3 of 0.15 mol dm -3 of an unknown bromate ion, BrO x - in acidic medium to form sulphur of mass 0.289 g