SJI 2021 Y4 Prelim Chemistry 6092 P2

ST JOSEPH’S INSTITUTION PRELIMINARY EXAMINATION 2021 (YEAR 4) CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 2 Candidates answer on the Question Paper. No Additional Materials are required. 6092/02 20 August 2021 1 hour 45 minutes (11:15 – 13:00) READ THESE INSTRUCTIONS FIRST Write your name, class and index number on all the work you hand in. Write in dark blue or black fluid ink 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 questions in the spaces provided. Section B Answer all three questions, the last question is in the form either/or. Answer all questions in the spaces provided. Candidates are reminded that all quantitative answers should include appropriate units. Candidates are advised to show all their working in a clear and orderly manner. The number of marks is given in brackets [ ] at the end of each question or part question. The use of an approved scientific calculator is expected, where appropriate. A copy of the Periodic Table is printed on page 2 of this question paper. For Examiner’s Use Section A / 50 B7 / 12 B8 / 8 B9 / 10 Total / 80 This document consists of 22 printed pages including this cover page.

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3 Section A Answer all questions in this section in the spaces provided. The total mark for this section is 50. A1 The chromatogram below shows the results of a paper chromatography experiment. (a) Draw a line, labelled S, on the chromatogram to show the solvent level at the beginning of the experiment. [1] (b) In this experiment, a locating agent i s used on the chromatogram. What is the purpose of a locating agent? ........................................................................................................................[1] (c) Use the chromatogram to answer the following questions. (i) Which substances are impure? ……………………………………...........................................................[1] (ii) Which substances are pure? ………………........................................................................................[1] solvent front start line

4 (d) With the aid of a ruler and indicating the measurements on the chromatogram clearly, calculate the Rf value of the most soluble spot in X. Rf value = .................................................. [2] [Total: 6] A2 This question is about ammonia. (a) Ammonia is manufactured indu strially using the Haber Process and is an important precursor used in