SRJC H2 Chem 2013 Prelim P2 QP

1   SRJC 9647/02/Prelim/2013 Turn Over]   SERANGOON JUNIOR COLLEGE General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CLASS CHEMISTRY 22 Aug 2013 9647/02 2 hours Preliminary Examination Paper 2 Structured Questions (SPA) Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name and class on all the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use a soft pencil for any diagrams, graphs or rough work. Answer all questions in the space provided. You are advised to spend 30 minutes on question 1. At the end of the examination, fasten all your work securely together. The number of marks is given in the brackets [ ] at the end of each question or part questions.                       This document consists of 16 printed pages For Examiner’s Use 1(P) /12 2 /12 3 /17 4 /12 5 /7 6 /12 TOTAL P2 /72 For Examiner’s Use P1 /40 P2 /72 P3 /80 GRAND TOTAL /192 % GRADE 1251

2   SRJC 9647/02/Prelim/2013 Turn Over]   Answer all questions in the space provided Planning 1 Hard water, or water that contains high mineral content, such as calcium ions, pose serious problems in many industries. Other potential ions that could be present include zinc (through corrosion of pipings) and aluminium ions (whereby aluminium salts are added during the water purification process to start certain precipitation reactions). You are provided with a water sample that may contain the cations Ca 2+, Al3+ and Zn2+. The solution may also contain carbonate ions, CO 3 2–, and halide ions (either bromide or iodide). You are given only the following to conduct your test. Reagent Apparatus  aqueous ammonia  tests tubes  aqueous sodium hydroxide  funnel  dilute sulfuric acid  filter paper (a) Using the above only, write out a plan to separate each cation into three separate solutions. In your plan you should:  give a full description of the procedures you would use;  indicate the expected observations in each step. .................................................................................................................................... .................................................................................................................................. ....