TJC_08 TJC Chem H2 Prelim P1

TEMASEK JUNIOR COLLEGE CHEMISTRY 9746/01 Paper 1 Multiple Choice Friday 19th SEPTEMBER 2008 1 hour Additional materials: Data Booklet Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Do not open this 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, index number and CG on the Answer Sheet in the spaces provided. There are forty questions on this paper. Answer all questions. For each question, there are four possible answers labelled 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. You may use a calculator. This document consists of 18 printed pages. [Turn over

2 TJC H2 Chemistry Paper 1 2008 [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 Ethanonitrile, CH3CN was boiled with NaOH and the NH 3 gas evolved was passed into 50 cm3 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 0.492 g B 0.984 g C 1.07 g D 1.97 g 2 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+ 3 Antimony, Sb, is in Group V of the Periodic Table. It forms salts which contain the SbF 5 n- anion, the shape of which is square pyramidal. What is the value of n? A 2 B 3 C 4 D 5

3 TJC H2 Chemistry Paper 1 2008 [Turn over 4 Which of the following compounds is the least volatile? A CH3CH2CH2CH2OH B (CH3)3COH C CH3CH2CH2CH2NH2 D (CH3)3CNH2 5 Each of the following equilibria is subjected to two changes carried out separately: (i) the volume of vessel is increased at constant temperature; (ii) the temperature is increased at constant pressure. For which equilibrium will both of these changes result in an increase in the proportion of products? A H2(g) + I2(g) 2H I(g) ∆H = +53 kJ mol-1 B 4NH3(g) + 5O2(g) 4NO(g) + 6H 2O(g) ∆H = -950 kJ mol-1 C N2O4(g) 2NO 2( g ) ∆H = +57 kJ mol-1 D N2(g) + 3H2(g) 2NH 3(g) ∆H = -92 kJ mol-1 6 What is the pH value of 0.05 mol dm -3 of ammonium chloride solution, given the Kb of NH3 is 1.8 x 10-5 mol dm-3? A 3.02 B 5.28 C 8.72 D 10.98