2023 SAJC H2 Chem Prelim P1 (QP)

ST ANDREW’S JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATIONS HIGHER 2 CANDIDATE NAME CLASS 2 2 S CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 9729/01 15 September 2023 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name and class 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. 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. This document consists of 15 printed pages (including this cover page) and 1 blank page.

2 1 The relative atomic mass of boron, which consists of the isotopes 10 5 B and 11 5 B is 10.8. What is the percentage of 11 5 B atoms in the isotopic mixture? A 0.2 % B 0.8% C 20 % D 80 % 2 A mixture of sodium iodide, 23Na127I, and sodium bromide, 23Na79Br, were vapourised and the ions passed through an electric field. Which statements about the results are correct? 1 There would be 4 angles of deflections observed. 2 The particle with the largest angle of deflection will be detected at the negative plate. 3 The positive plate will detect more particle types than the negative plate. A 1 only B 2 and 3 only C 1 and 2 only D 1,2 and 3 3 Which of the following statements about ice and its structure is correct? A The bond angle around O in ice is 109.5°. B Ice is more dense than water. C 2 electrons on O in ice are involved in hydrogen bonding. D Hydrogen bonds formed in ice are as strong as the O-H covalent bonds. 4 Benzylamine is commonly used in the industrial production of many pharmaceutical products and has the following structure. NH2 Which bond angle is not present in benzylamine? A 105° B 107° C 109.5° D 120° 5 In a vessel, 5.0 dm3 of nitrogen gas at 20 °C and pressure of 200 kPa was compressed by a piston to 2.5 dm3 and heated to 60 °C. What is the pressure in the heated vessel? A 90 kPa B 455 kPa C 715 kPa D 1200 kPa

3 [TURN OVER 6 Magnesium, aluminium, silicon and phosphorus are consecutive elements in Period 3 of the Periodic Table. Which of the following properties generally decreases from magnesium to phosphorus? 1 Electrical conductivity 2 Ionic radius 3 Melting point of their oxides 4 pH of their chlorides in water A 1 and 2 only B 1 and 3 only C 2 and 4 only D 3 and 4 only 7 Which of the following properties of a salt will make it the most soluble in water? size of the ions magnitude of their lattice energy A small small