2020 HCI Prelim Paper 1 Question Paper

This document consists of 16 printed pages. HWA CHONG INSTITUTION C2 Preliminary Examinations Higher 2 CANDIDATE NAME CT GROUP 19S CENTRE NUMBER INDEX NUMBER CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 9729/01 21 September 2020 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Complete the information on the Answer Sheet as shown below. There are 30 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 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. The use of an approved scientific calculator is expected, where appropriate.

© Hwa Chong Institution 2020 9729/01/C2Prelim 2020 [Turn over 2 1 Use of the Data Booklet is relevant to this question. In which pairs do both species have different number of unpaired p electrons? A Al2− and O+ B N and Cl2+ C C and Cl+ D B− and S+ 2 Four substances have the physical properties shown. Which substance exists as a simple molecular solid at room temperature? melting point/ C electrical conductivity solubility in water A −7 does not conduct slightly soluble B 46 does not conduct insoluble C 420 conducts insoluble D 782 does not conduct soluble 3 Which statement about covalent bonds is incorrect? A The electron density in a  bond is highest along the axis between the two bonded atoms. B Covalent bonds can occur together with ionic bonds in the same compound. C A triple bond consists of one  bond and two  bonds. D A  bond restricts rotation about the  bond axis. 4 Which statement about an ideal gas is correct? A The density of an ideal gas at constant temperature is inversely proportional to the pressure. B One mole of any ideal gas occupies the same volume under the same conditions of temperature and pressure. C The volume of a given mass of an ideal gas is doubled if its temperature is raised from 25 C to 50 C at constant pressure. D Adding an inert gas to an ideal gas at constant volume and temperature will increase the partial pressure of the ideal gas.

© Hwa Chong Institution 2020 9729/01/C2Prelim 2020 [Turn over 3 5 When 10 cm3 of a gaseous organic compound were completely burnt in an excess of oxygen, 30 cm3 of carbon dioxide and 5 cm 3 of nitrogen were formed, all volumes being measured at the same temperature and pressure. Which could be the formula of the organic compound? A C2H6N2 B C2H7NO C C3H7N2 D C3H5N 6 A saturated solu