2013_MJC_H1_Chemistry_P2 QP

©MJC Chemistry Name: ___________________ Class: ________ Reg Number: _____ MERIDIAN JUNIOR COLLEGE JC2 Preliminary Examination Higher 1 _____________________________________________________________________ Chemistry 8872/02 Paper 2 17 September 2013 2 hours Additional Materials: Data Booklet Writing Papers _____________________________________________________________________ READ THESE INSTRUCTIONS FIRST Write your name, class and register number in the spaces at the top of this page. This booklet contains Section A and Section B. Section A : Pg 2 to 13 Answer all questions in Section A in the spaces provided on the question paper. You are advised to spend about 1 h on Section A. Section B : Pg 14 to 20 Answer 2 out of 3 questions in Section B. You are advised to spend about 1 h on Section B. Hand in Section B separately from Section A. Fasten your answers for Section B behind the given Cover Page. Detach the Cover Page from the last page behind this booklet. INFORMATION FOR CANDIDATES The number of marks is given in brackets [ ] at the end of each question or part question. _____________________________________________________________________ This document consists of 20 printed pages (including this cover page) Examiner’s Use Paper 1 MCQ / 30 m / 33 % Paper 2 Section A Q1 / 12 m Q2 / 17 m Q3 / 11 m Paper 2 Section B / 40 m Paper 2 Total / 80 m / 67 % Grand Total / 100 % Grade

2 [Turn Over Section A : Structured Questions Answer all the questions in this section in the spaces provided. 1 An early Periodic Table devised by Mendeleev listed the elements known then in order of their relative atomic mass. (a) (i) When Mendeleev created the table, there were uncertainties regarding the relative atomic mass of tellurium. It is now known that there are eight isotopes of tellurium. Complete the following table. Give your answers to four significant figures. isotope percentage abundance isotopic mass x percentage abundance tellurium-120 0.09 11.00 tellurium-122 2.46 300.0 tellurium-123 0.87 107.0 tellurium-124 4.61 572.0 tellurium-125 6.99 874.0 tellurium-126 18.71 2357 tellurium-128 31.79 tellurium-130 Hence, calculate the relative atomic mass of tellurium to 1 decimal place.

3 [Turn Over (ii) The electronic configuration of tellurium and antimony are as follows: Te: [Kr]5s25p4 Sb: [Kr]5s25p3 Explain why the first ionisation energy of tellurium is lower than that of antimony. ……………………………………………………………………………………..… ………………………………………………………………………………..……… ………………………………………………………………………………….…[4] (b) Tellurium (IV) chloride, TeCl4, exists as a vapour at 380°C. Gaseous TeC l4 has a structure similar to sulfur tetrafluoride, SF4. (i) Draw a dot-and-cross diagram of TeCl4. (ii) Predict, with reasoning, the shape of TeCl4. ………………………………………………………………………