TJC_H1 Prelim Paper 1(with ans)

TEMASEK JUNIOR COLLEGE Preliminary Examinations Higher 1 CHEMISTRY 8872/01 Paper 1 Multiple Choice 19th September 2008 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, CG and index number on the Answer Sheet in the spaces provided. 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 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. This document consists of 15 printed pages.

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 Ethanonitrile, CH 3CN, was boiled with NaOH and the NH 3 gas evolved was passed into 50 cm 3 of 1.00 mol dm -3 of HC l. The excess acid required 26.00 cm 3 of 1.00 mol dm-3 NaOH solution for neutralization. What was the mass of ethanonitrile used? (Mr of CH3CN = 41) A 0.492g B 0.984g C 1.07g D 1.97g 2 Thallium(III) ions can oxidize iodide ions to iodine. 25.0 cm3 of a 0.0480 mol dm -3 solution of T l3+ ions was added to excess potassium iodide solution. The liberated iodine is titrated against 0.106 mol dm -3 sodium thiosulphate. 22.60 cm 3 of sodium thiosulphate solution was required to react with iodine in the following reaction. I2 + 2S2O3 2- → 2I- + S4O6 2- What was the oxidation state of Tl after its reaction with potassium iodide? A -1 B 0 C +1 D +2 3 Which of the following species has an electronic configuration of 1s22s22p63s23p63d5? A Cr+ B Mn C V D Fe2+ TJC 2008 8872/01/PRELIM 2008 [Turn over

3 4 Which of the following has the most number of unpaired electrons? A Al B Co3+ C NO D V2+ 5 In which of the following pairs does the first species have a larger bond angle than the second? A ClO3 -, BrO3 - B SO3 2-, SO4 2- C PCl3, AlCl3 D H2O, H3O+ 6 Antimony, Sb, is in Group V of the Periodic Table. It forms salts which contain the SbF5 n- anion, the shape of which is square pyramidal. What is the value of n? A 2 B 3 C 4 D 5 TJC 2008 8872/01/PRELIM 2008