RVHS Prelim P2_QP

River Valley High School 9647/02/PRELIM/15 2015 Preliminary Examination II RIVER VALLEY HIGH SCHOOL YEAR 6 PRELIMINARY EXAMINATION (II) CANDIDATE NAME CLASS 6 CENTRE NUMBER S INDEX NUMBER H2 CHEMISTRY 9647/02 Paper 2 Structured Questions 14 September 2015 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, class, centre number and index number on all the work you hand in. Write in dark blue or black pen on both sides of paper. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Answer all questions in the space provided. A Data Booklet is provided. Do NOT write anything on it. 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 Paper 2 Question Number 1 2 3 4 5 6 Total Marks 12 14 14 8 9 15 72 Paper 1 40 Paper 3 80 Total 192 This document consists of 20 printed pages.

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3 River Valley High School 9647/02/PRELIM/15 2015 Preliminary Examination II 1 Heavy metals, in the form of soluble ions, are common contaminants of industrial wastewaters. Due to their toxicity, they are typically removed prior to wastewater discharge. The heavy metal contents of wastewaters can be effectively removed to acceptable levels by precipitating the metal in an insoluble form. (a) Each of the sample solution s, P and Q, contains a type o f heavy metal ion. The ion is either silver(I) or zinc. The following shows the results of a chemical test on lead( II) ions and the two unknown samples. Test P Q Lead(II) ion To 1 cm3 of sample in a test-tube, add potassium chloride solution, followed by excess aqueous ammonia. No precipitate formed. White ppt formed is soluble in excess aqueous ammonia. White ppt formed is insoluble in excess aqueous ammonia. (i) Write an equation, with state symbols, for the reaction involving lead(II) ion. ……………………………………………………………………………... [1] (ii) Deduce the identity of ion Q and explain the observations reported. Q: ………………………………………………….. Explanation: ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ……………………………………………………………………………... [2]

4 River Valley High School 9647/02/PRELIM/15 2015 Preliminary Examination II (ii) Suggest a chemical test to confirm the identity of P. Describe the expected observation. Chemical Test: ………………………………………………………………………………… ………………………………………………………………………………… …………………………………………………………………………………. Observation: ………………………………………………………………………………… ………………………………………………………………………………… ……………………………………………………………………………... [2] (b) T