ASRJC 2021 J2Prelims H2Chem P2 QP

ASRJC JC2 PRELIMS 2021 9729/02/H2 [Turn over ANDERSON SERANGOON JUNIOR COLLEGE 2021 JC 2 PRELIMINARY EXAMINATION NAME:_________________________________ ( ) CLASS: 21 /____ CHEMISTRY 9729/02 Paper 2 Structured Questions 14 September 2021 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, class and register number in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB 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. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Paper 2 1 /21 2 /10 3 /13 4 /10 5 /11 6 /10 Total /75 This document consists of 23 printed pages and 1 blank page.

2 ASRJC JC2 PRELIMS 2021 9729/02/H2 Answer all the questions in the spaces provided. 1 (a) Describe and explain the trend in electronegativity of elements across Period 3 from sodium to chlorine. ………………………………………………………………………………………………………….. ………………………………………………………………………………………………………….. ………………………………………………………………………………………………………….. ………………………………………………………………………………………………………….. ………………………………………………………………………………………………………….. ………………………………………………………………………………………………………….. ……………………………………………………………………………………………………….[2] (b) Some ionic radii are listed in the Data Booklet. (i) Explain the trend in ionic radius down Group 2. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………[2] (ii) Explain the differences between the ionic radii of P3–, Cl– and Ca2+. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………[1] (iii) Hence, suggest a value for the ionic radius of a potassium ion, K+. …………………………………………………………………………………………………[1]

3 ASRJC JC2 PRELIMS 2021 9729/02/H2 [Turn over (iv) Explain the difference in size between the radius of the potassium ion and the radius of a potassium atom. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………[1] (c) Anodisation of aluminium is a process which coats an oxide layer on aluminium objects. (i) Draw a labelled diagram of the electrolysis cell used to anodise a small piece of aluminium object. Include details of the cathode, anode and electrolyte. [1] (ii) Complete Tabl