NYGH 2012-S3EOY-Chem P2

Class Register Number Name 南洋女子中学校 NANYANG GIRLS’ HIGH SCHOOL End-of-Year Examination 2012 Secondary Three CHEMISTRY 1 hour 45 minutes Paper 2 0915 to 1100 Thursday 11 October 2012 Additional materials: Writing papers READ THESE INSTRUCTIONS FIRST Do not open this booklet until you are told to do so. Write your name, register number and class in the spaces at the top of this page and on any separate answer paper used. Section A (40 marks) Answer all questions and write your answers in the spaces provided on the question paper. Please note that if you do not write your answers in the spaces provided specially for that purpose, that section of the paper will be awarded ZERO marks. Section B (30 marks) Answer all questions including questions 6, 7 and 8 Either or 8 Or. Write your answers on the separate writing paper provided. At the end of the examination, 1. fasten all your work securely together; 2. tick 8 Either (for Either) or 8 Or (for Or) in the grid below to indicate which question you have answered. INFORMATION FOR CANDIDATES Examiner’s Use Section A Section B 6 7 8 Either 8 Or Total The intended number of marks is given in the brackets [ ] at the end of each question or part question. You are advised to spend no longer than one hour on Section A and no longer than 45 minutes on Section B. Use of Scientific Calculator is allowed. A copy of the Periodic Table is found on page 12. Setters: ZJ/CW/ET This document consists of 12 printed pages. NANYANG GIRLS’ HIGH SCHOOL [Turn over

2012 End-of-Year Examination Secondary Three 2 Nanyang Girls’ High School Setters: ZJ/CW/ET Chemistry / II Section A Answer all questions in the spaces provided. A1 The electronic configurations of the atoms of two elements, V and W, are listed below. V: 2. 5 W: 2. 8. 2 (a) Predict and explain which element, V or W, has a lower melting point. [3] (b) Another element R, in the same period as W, forms a compound with oxygen with the formula R2O. R2O is a gas at room temperature. (i) Predict whether R2O will conduct electricity in molten state. [1] (ii) Draw the ‘dot and cross’ diagram for the compound R2O. [2] (c) A new element U was discovered and two of its properties were listed below. 1. It forms a compound with V with the formula U 3V2. 2. U3V2 is a conductor of electricity in molten and aqueous state. (i) Suggest a suitable Group in the Periodic table to place the new element U. [1] [Total marks: 7]

2012 End- of-Year Examination Secondary Three 3 Nanyang Girls’ High School Setters: ZJ/CW/ET Chemistry / II [Turn over (ii) State and explain whether element U is able to conduct electricity in the solid state. [2] A2 In the preparation of magnesium nitrate, a reac