2012 JJC H1 Prelim P1

JURONG JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 1 CHEMISTRY 8872/01 Paper 1 Multiple Choice 13 September 2012 50 minutes Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters,glue or correction fluid. Write your name, class and shade your exam index number on the Answer Sheet in the spaces provided. There are thirty questions on this pape r. 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 a wrong answer. Any rough working should be done in this booklet. A Data Booklet is provided. Do not write anything on the Data Booklet. This document consists of 11 printed pages and 1 blank page. [Turn over

2 Jurong Junior College 8872/01/Prelim 2012 [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. 1. 0.200 mol of a hydrocarbon undergo complete combustion to give 35.2 g of carbon dioxide and 14.4 g of water as the only products. What is the molecular formula of the hydrocarbon? A C2H4 B C2H6 C C4H4 D C4H8 2. A giant molecule contains a mixture of two carbon isotopes, 12C and 13C. It was found that the relative atomic mass of carbon in the molecule is 12.20. What is the ratio of 12C to 13C in the molecule? A 5:4 B 4:1 C 4:5 D 1:4 3. The use of Data Booklet is relevant to this question. In research on the atomic nucleus, scientists have been comparing the stability of isotopes with the same neutron : proton ratio. Which isotope has the same neutron : proton ratio as 10B? A 32P B 40Ar C 32S D 40K 4. Which element has an equal number of electron pairs a nd of unpaired electrons in the orbitals of principal quantum number 2? A beryllium B carbon C nitrogen D oxygen

3 Jurong Junior College 8872/01/Prelim 2012 [Turn Over 5. A plasma is a gaseous mixture in which the atoms have been completely stripped of their electrons, leaving bare nuclei. Due to possible use in controlled nuclear fusion reactions, plasma behavior has been intensively studied. When passed between two elect rically charged plates, 1H and 4He nuclei are deflected differently. The deflection path of 1H is shown in the diagram below. Which of the following is correct? Polarity of Plate direction of deflection of 4He angle of deflection of 4He X Y A – + towards Y 0.5 ° B + – towards Y 1 ° C – + towards X 1 ° D +