RI 2018 Prelim P2 QP

© Raffles Institution 2018 9729/02/S/18 [Turn Over RAFFLES INSTITUTION 2018 YEAR 6 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY 9729/02 Paper 2 Structured Questions 11 September 2018 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Do not open this question booklet until you are told to do so. Write your name, class and index number in the spaces provided at the top of this page. Write in dark blue or black pen in the spaces provided. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Answer all questions. A Data Booklet is provided. Do not write anything in it. You are reminded of the need for good English and clear presentation in your answers. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use 1 / 8 2 / 13 3 / 16 4 / 13 5 / 10 6 / 15 Total / 75 This document consists of 23 printed pages.

For examiner’s use 2 © Raffles Institution 2018 9729/02/S/18 [Turn Over Answer all the questions in the spaces provided. 1 Gemstones such as amethysts, pearls and malachites contain compounds of main group and transition elements. Fig. 1.1 shows the logarithm of the ionisation energies, log (IE), for the outermost ten electrons in an atom of an element X, which has atomic number smaller than 20. number of electrons removed Fig. 1.1 (a) Deduce which G roup in the Periodic Table X belongs to and state the identity of X. Explain your answer. ………………………………………………….………..………………………………………... ……………………………………………….……………………………………………….....… ……………………………………………….………………………………………………….… ………………………………………………..………………………….…………….…….…[3] (b) The colour of amethyst is caused by the presence of compounds containing manganese and iron. Explain why the first ionisation energies of manganese and iron are similar. ……………………………………….……………………………………………….……....…… ……………………………………….…………………………………………………….....…… ……………………………………….…………………………………………………….....…… ………………………………………………….…………………………………………..……... ……………………………………………….………………………………………..………...… ………………………………………………..………………………….…………….…….…[3] 1 2 3 4 5 6 7 8 9 10 11 log (IE)

For examiner’s use © Raffles Institution 2018 9729/02/S/18 [Turn Over 3 (c) Use of the Data Booklet is relevant to this question. Malachites contain copper(II) carbonate while pearls contain calcium carbonate. Predict whether calcium carbonate or copper( II) carbonate has a higher decomposition temperature. Explain your answer. …………………………………………………………………………………………….………. …………………………………………………………………………………………….….…… …………………………………………………………………………………………….………. …………………………………………………………………………………………….….…… …………………………………………………………………………………………….……