HCI Prelim P1

HWA CHONG INSTITUTION C2 PRELIMINARY EXAMINATION 8872 H1 CHEMISTRY PAPER 1 Multiple Choice 29 September 2009 50 minutes   Do not open this booklet until you are told to do so. READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Complete the information on the optical mark sheet (OMS) as shown below. Write your CT group Write your CT group Write and shade your NRIC or FIN number Write your name There are thirt y 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 OMS. 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 10 printed pages.

HCI(College) 2009 8872/01/C2 Prelim/09 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 The relative abundances of the isotopes of a sample of titanium are shown in the table below. What is the relative atomic mass of titanium in this sample? Relative Isotopic Mass 46 47 48 49 50 Relative Abundance 11.2 10.1 100.0 7.3 7.0 A 47.92 B 47.91 C 47.90 D 47.89 2 In the middle of the 15 th century, ‘black powder’ was widely used by the Arabs as propellant for muzzle-loading cannons. ‘Black powder’ consis ted of a mixture of potassium nitrate, sulfur and charcoal (carbon) in the molar ratio shown in the equation below. 2KNO3 (s) + S (s) + 3C (s)  K2S (s) + N2 (g) + 3CO2 (g) Given that 2.00 mol of gas could just expel the cannonball out of the cannon tube, what is the minimum mass of ‘black powder’ (in g), required for this to happen? [M r: KNO3, 101.1] A 101 B 135 C 202 D 270 3 Which of the following contains 1 mol of the stated particles? A electrons in 1 g of hydrogen gas B chlorine molecules in 35.5 g of chlorine gas C oxygen atoms in 22.4 dm 3 of oxygen gas at s.t.p. D hydrogen ions in 1 dm3 of 1 mol dm−3 aqueous sulfuric acid 4 The successive ionisation energies (IE) of two elements, Q and R, are given below. IE / kJ mol−1 1 st 2 nd 3 rd 4 th 5 th 6 th 7 th 8 th Q 1090 2350 4610 6220 37800 47000 - - R 1251 2298 3822 5158 6542 9362 11018 33604 What is the likely formula of the compound that is formed when Q reacts with R? A QR B Q 2R3 C QR4 D Q4R

3 5 What is th e electronic configuration of an atom of the element which is isoelectronic with H2S? A 1s2 2s2 2s6 3s2 B 1s2 2s2 2s6 3s2 3p2 C 1s2 2s2 2s6 3s2 3p4 D 1s2 2s2 2s6 3s2 3p6 6 Which of the following statements about the properties associated with ionic and covalent bonds is correct? A Some covalent compounds can serve as electrolyte in water.