2019 ASRJC Prelim H2 Chem P2 QP

ASRJC JC2 PRELIMS 2019 9729/02/H2 [Turn over ANDERSON SERANGOON JUNIOR COLLEGE 2019 JC 2 PRELIMINARY EXAMINATIONS NAME:_____________________________________ ( ) CLASS: 19 /____ CHEMISTRY 9729/02 Higher 2 4 September 2019 Paper 2 Structured Questions 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, index number and class on all the work you hand in. Write in dark blue or black pen. You may use a pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions in the spaces provided on the Question Paper. The use of an approved scientific calculator is expected, where appropriate. A Data Booklet is provided. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Paper 2 1 / 12 2 / 11 3 / 18 4 / 13 5 / 12 6 / 9 Total / 75 This document consists of 26 printed pages and 2 blank pages.

2 ASRJC JC2 PRELIMS 2019 9729/02/H2 1 (a) Use the data from Table 1.1 to state and explain the relative reactivity of Group 2 elements as reducing agents. Table 1.1 Element Eo [M2+(aq)/M(s)] / V Mg –2.38 Ca –2.87 Sr –2.89 Ba –2.90 …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… ……………………………………………………………………………………………………..… [2] (b) Table 1.2 gives data about some physical properties of calcium and copper. Table 1.2 calcium copper relative atomic mass 40.1 63.5 atomic radius (metallic) / nm 0.197 0.128 ionic radius (2+) / nm 0.099 0.069 electrical conductivity / 106 S cm1 0.298 0.596 density / g cm3 1.54 8.92 (i) Explain why the electrical conductivity of copper is higher than that of calcium. …………………………………………………………………………………………………...... …………………………………………………………………………………………………..... …………...……………………………………………………………………………………...... …………..…………………………………………………………………………………..… [2]

3 ASRJC JC2 PRELIMS 2019 9729/02/H2 [Turn over (ii) Using relevant data from T able 1.2, explain why the density of copper is significantly greater than that of calcium (no calculations are required). …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………. [2] (c) (i) Copper is a typical transition element and is used in alloys for aircraft engine parts. Which of the following “electrons –in–boxes” diagrams best descri