RI_Prelim_H1_P1

1 © RAFFLES INSTITUTION (JUNIOR COLLEGE) 2009 8872/P01/09 [Turn Over RAFFLES INSTITUTION (JC) PRELIMINARY EXAMINATION 2009 HIGHER 1 CHEMISTRY 8872/01 Paper 1 Multiple Choice 24 Septembe r 2009 50 minutes Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Do not open this question booklet until you are told to do so. Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, class and index number in the spaces provided on the Answer Sheet. There are thirty 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 to be correct and record your choice with a 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 a wrong answer. Any rough working should be done in this booklet. This document consists of 14 printed pages. Raffles Institution Junior College

2 © RAFFLES INSTITUTION (JUNIOR COLLEGE) 2009 8872/P01/09 [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 and record your choice on the Multiple Choice Answer Sheet provided. 1. Naturally occurring silicon is a mixture of three isotopes, 28 Si, 29 Si and 30 Si. The relative atomic mass of silicon is 28.109. What could be the relative abundance of each of the three isotopes? A 91.1 % 28 Si, 7.9 % 29 Si and 1.0 % 30 Si B 92.2 % 28 Si, 4.7 % 29 Si and 3.1 % 30 Si C 95.0 % 28 Si, 3.2 % 29 Si and 1.8 % 30 Si D 96.3 % 28 Si, 0.3 % 29 Si and 3.4 % 30 Si 2. 10 cm 3 of a hydrocarbon was completely burnt in 100 cm 3 of oxygen. The volume of the residual gas obtained was 80 cm 3. When the residual gas was shaken with aqueous sod ium hydroxide, the volume decreased to 20 cm 3. Which one of the following represents the structure of the hydrocarbon? (All volumes are measured at room temperature and pressure). A C B D 3. 20.0 cm 3 of 0.0200 mol dm −3 bromate( V), BrO 3 − , was found to react completely with 80.0 cm 3 of 0.0100 mol dm −3 hydroxylamine, NH 2OH. BrO 3 − ions are reduced as follows: BrO 3 – + 6e – + 6H + → Br − + 3H 2O