ASRJC 2022 J2 H2Prelim P2 QP

ASRJC JC2 PRELIM 2022 9729/02/H2 [Turn over ANDERSON SERANGOON JUNIOR COLLEGE 2022 JC 2 PRELIMINARY EXAMINATION NAME:______________________________ ( ) CLASS: 22 / _____ CHEMISTRY 9729/02 Paper 2 Structured Questions 14 September 2022 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, class and register number on all the work you hand in. 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 / 10 2 / 12 3 / 15 4 / 10 5 / 18 6 / 10 s.f./units Total / 75 This document consists of 21 printed pages and 3 blank pages.

2 ASRJC JC2 PRELIM 2022 9729/02/H2 Answer all the questions. 1 (a) Calcium, magnesium, and zinc are three minerals that are vital to several bodily processes. Though they occur naturally in a variety of food, many people take supplements that contain these minerals usually found in the +2 oxidation state. (i) State and explain how the second ionisation energy of calcium compares with that of magnesium. ………………………………………………………………………………………………....... ………………………………………………………………………………………………....... ………………………………………………………………………………………………....... ………………………………………………………………………………………………....... ………………………………………………………………………………………………...[2] (ii) By quoting relevant data from the Data Booklet, suggest how the thermal stability of ZnCO3 compares with that of MgCO3 and CaCO3. Explain your answer. ………………………………………………………………………………………………....... ………………………………………………………………………………………………....... ………………………………………………………………………………………………....... ………………………………………………………………………………………………....... ………………………………………………………………………………………………...[2] (b) Beryllium exhibits physical and chemical properties that are anomalous to the rest of the Group 2 alkaline earth metals. Due to the similarities in electronegativity, beryllium shares many physical and chemical properties with aluminium in Group 13 instead. (i) Beryllium forms a complex ion in aqueous solutions with the following structure, [Be(H2O)4]2+. Suggest an equation to show the hydrolysis of beryllium ions in water. ………………………………………………………………………………………………...[1] (ii) Beryllium oxide is amphoteric. Write two chemical equations, with state symbols, showing its reaction with aqueous NaOH and dilute HCl respectively. ………………………………………………………………………………………………....... ………………………………………………………………………………………………...[2]