ACJC_H1_CHEM_P2_Qn_paper

Index No. Name Form Class Tutorial Class Subject Tutor ANGLO-CHINESE JUNIOR COLLEGE DEPARTMENT OF CHEMISTRY Preliminary Examination CHEMISTRY 8873/02 Higher 1 Paper 2 16 August 2018 2 hours Candidates answer on the Question Paper Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, index number, form class, tutorial class and subject tutor’s name on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. Section A Answer all the questions. Section B Answer one question. The use of an approved scientific calculator is expected, where appropriate. 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 Question no. Marks Section A B7 B8 Presentation of answers TOTAL This document consists of 22 printed pages and 2 blank pages. 8873/02/Prelim/18 ANGLO-CHINESE JUNIOR COLLEGE © ACJC 2018 Department of Chemistry [Turn over

2 © ACJC 2018 8873/02/Prelim/2018 [Turn over BLANK PAGE

3 © ACJC 2018 8873/02/Prelim/2018 [Turn over Section A Answer all the questions in this section, in the spaces provided. 1 (a) Hydrogen sulfide, H 2S, is a foul-smelling compound found in the gases from volcanoes. Hydrogen sulfide has a melting point at –85°C and boiling point at –60°C. (i) State the structure of hydrogen sulfide. ……………………………………………………………………………………[1] (ii) Draw a ‘dot-and-cross’ diagram to show the structure of H 2S. [1] (iii) State and explain the shape of H 2S. ……………………………………………………………………………………… ……………………………………………………………………………………[2] (iv) Oxygen and sulfur are both in Group 16 of the Periodic Table. Suggest why the melting and boiling points of water, H 2O, are much higher than those of H2S. ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………[3]

4 © ACJC 2018 8873/02/Prelim/2018 [Turn over (b) Hydrogen sulfide burns with a blue flame in an exce