MJC_H1_CHEM_P2

No part of this paper should be repro duced for commercial use without the prior written permission of Meridian Junior College. Name : ______________________ Class: ______ Reg Number: _____ Meridian Junior College 2009 JC2 Preliminary Examination H1 Chemistry 8872 14 September 2009 2 hours Paper 2 Candidates to answer Section A on the Question Paper and Section B on separate writing paper. Additional Materials: Data Booklet Writing paper INSTRUCTION TO CANDIDATES Write your name, class and register number in the spaces provided at the top of this page. Section A Examiner’s Use Paper 1 MCQ / 30 Q1 / 7 Q2 / 8 Q3 / 10 Answer all questions. Section B Answer any tw o questions. Paper 2 Section A At the end of the examination, fasten your answers for Section B behind Section A. INFORMATION FOR CANDIDATES Q4 / 15 Q5 / 20 Q6 / 20 The number of marks is given in brackets [ ] at the end of each question or part question. You are reminded of the need for good English Paper 2 Section B and clear pr esentation in your answers. Q7 / 20 Total / 110 This question paper consists of Page 1 to 19. ©chemistry department@meridian jc [Turn over

Section A Answer all the questions in this section in the spaces provided. 1(a) Magnesium bromide, MgBr 2, is a white solid that readily absorbs moisture from the atmosphere. It is often used as a mild sedative. (i) Using magnesium bromide as an exam ple, explain what is meant by the term lattice energy. (ii) Use the energy level diagram, together with the given data to determine the lattice energy of magnesium bromide . Enthalpy change of hydration of magnesium ion, ∆Hhyd( 2+Mg ) -1921 kJ mol-1 Enthalpy change of hydration of bromide ion, ∆Hhyd( -Br ) -336 kJ mol-1 Enthalpy change of solution of magnesium bromide, Hsoln(MgBr2) -186 kJ mol-1 ∆H soln (MgBr2) Mg2+(g) + 2Br-(g) ∆Hhyd( 2+gM ) + 2 x ∆Hhyd( -Br ) ∆Hlatt MgBr2 (s) Mg2+(aq) + 2Br-(aq) ©chemistry department@meridian jc [Turn over 1

(iii) Explain how you would expect the num erical magnitude of the lattice energy of MgBr2 to compare with that of sodium fluoride, NaF. [4] (b) (i) With the aid of an equation, define the first ionisation energy of iodine. (ii) State and explain how you would expect the first ionisation energy of iodine to compare with that of fluorine. [3] [Total : 7] ©chemistry department@meridian jc [Turn over 2

2 Early Periodic Tables, such as that devised by Mendeleev, listed the then known elements in order of their relative atomic mass. (a) When Mendeleev created the table, ther e were uncertainties regarding the relative atomic mass of tellurium. It