AJC_Prelims H2 Chem Paper1_ Question paper

AJC/H2 Chemistry/Prelims2008 [Turn over 1 ANDERSON JUNIOR COLLEGE Preliminary Examination 2008 CHEMISTRY 9746/01 Higher 2 15 Sep 2008 Paper 1 Multiple Choice 1 hour Additional Materials: Multiple Choice Optical Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. 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 Optical Answer Sheet. 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. Optical Answer Sheet Write your name and PDG. Shade the last 5 digits of your NRIC / FIN number. DO NOT shade the reference letter. This document consists of 14 printed pages.

AJC/H2 Chemistry/Prelims2008 [Turn over 2 Section A For each question there are four possible answers, A, B, C and D. Choose the one you consider to be correct. 1 To determine the mass of arsenic present in a sample of pesticide, all the arsenic was first converted to arsenate ion, AsO 4 3-. 1.25 × 10-3 moles of AgNO 3 was then added to precipitate AsO4 3- as Ag3AsO4. The excess Ag + ions needed 3.64 cm 3 of 0.054 mol dm -3 KSCN to form silver thiocyanate, AgSCN. Calculate the mass of arsenic (A r = 74.9) present in the sample of pesticide. A 0.015 g B 0.026 g C 0.079 g D 0.488 g 2 An aqueous solution contains 1 mole of S2O3 2- ions and this reduces 4 moles of Cl2 molecules. What is the sulphur-containing product of this reaction? A SO2 B SO3 2- C SO4 2- D S4O6 2- 3 Three identical flasks each contains the same mass of gases E, F and G respectively. The temperature and pressure of each flask are indicated below. Temperature / oC t Gas E Gas F Gas G t 2t Pressure / atm p 2p p Assuming ideal gas behaviour, which of the followi ng is a correct representation of the relative molecular masses of the three gases? A Mr(G) > Mr(E) > Mr(F) B Mr(G) > Mr(F) > Mr(E) C Mr(E) > Mr(F) > Mr(G) D Mr(E) > Mr(G) > Mr(F) 4 The ion X2+ has 54 electrons and 81 neutrons. Which of the following statements is true? A Element X is isoelectronic with xenon. B The first ionization energy of element X is higher than that of Mg. C The oxide of X formed is expected to have a higher melting point than MgO. D In an electric field, the ion X2+ will be deflected at a smaller angle than that of Mg2+. 5 Which of the following statements cannot be explained by hydrogen bonding?