2022 HCI H2 Chemistry Promo P1 QP

This document consists of 11 printed pages and 1 blank page. HWA CHONG INSTITUTION C1 Promotional Examination Higher 2 CANDIDATE NAME CT GROUP 22S CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 9729/01 28 September 2022 40 min READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Complete the information on the Multiple Choice Answer Sheet as shown below. There are twenty 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. 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.

2 © Hwa Chong Institution 2022 9729/01/C1 Promotional Exam 2022 [Turn over 1 Use of the Data Booklet is relevant to this question. Nuclear theories predict the number of protons and the number of neutrons that give especially stable nuclei. These numbers are known as the nuclear magic numbers. These numbers include 2, 8, 20, 28, 50, 82, 126. The most stable nuclei are the ‘doubly magic’ ones that have a magic number of protons and a magic number of neutrons. Using this theory, which isotope is the most stable? A 2He B 8Be C 40Ca D 210Pb 2 Cyanogen, (CN)2, is a colorless, toxic gas with a pungent smell. N C C N cyanogen Which statements about the cyanogen molecule are correct? 1 It contains two lone pairs of electrons. 2 It contains sp hybridized carbon atoms. 3 It contains a total of four π bonds and two σ bonds. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1 only

3 © Hwa Chong Institution 2022 9729/01/C1 Promotional Exam 2022 [Turn over 3 In the solid phase, molecules of hydrogen fluoride, HF, are held together by hydrogen bonding in a regular arrangement like water molecules in ice. The bond angle around the F atom is also similar to that around the O atom in ice. However, each HF molecule forms only two hydrogen bonds with neighboring HF molecules in zig- zag chains as shown: Which statement about solid HF is correct? A Solid HF has the same open structure as in ice. B Each hydrogen bond in solid HF is stronger than that in ice. C The bond angle around each F atom is approximately 120°. D The chains form part of a giant covalent structure in solid HF. 4 A flask of fixed volume contains a mixture of nitrogen gas and oxygen gas. Which changes would apply when some helium gas is introduced into the flask at constant temperature? 1 The total pressure of gas in the flask would increase. 2 The mole fractions of n