JPJC Prelim P3 QP

¤ Jurong Pioneer Junior College [Turn Over NAME CLASS 20S JURONG PIONEER JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATION 2021 CHEMISTRY 9729/03 Higher 2 Paper 3 Free Response Questions 20 September 2021 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name and class on all the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use a 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. If additional space is required, you should use the pages at end of this booklet. The question number must be clearly shown. Section A Answer all questions. Section B Answer one question. 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 1 20 2 20 3 20 4 or 5 20 Penalty (delete accordingly) Lack 3sf in final answer –1 / NA Missing/wrong units in final ans –1 / NA Bond linkages –1 / NA Total 80 This document consists of 27 printed pages and 1 blank page.

2 ¤ Jurong Pioneer Junior College 9729/03/J2 PRELIMINARY EXAMINATION/2021 Answer all the questions. 1 Period 3 elements react with oxygen and nitrogen in various ways. For ([DPLQHU¶V Use (a) Compounds A, B and C are the solid oxides of three Period 3 elements. x When excess cold water is added separately to A, B and C, only B and C are able to dissolve readily. x The resulting aqueous solution from B reacts with solid sodium carbonate in a mole ratio of 2:3. Effervescence is observed. x The resulting aqueous solution from C reacts with solid ammonium nitrate to give a pungent gas upon heating. x When A is added separately to the resulting aqueous solutions from B and C, it dissolves. State and explain the identities of A, B and C. You are to include the equations for the reactions of the oxides, B and C with water. [6] ...................................................................................................................................... …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. ……………………………………………………………………