RVHS_H2_CHEM_P2 Prelim

RIVER VALLEY HIGH SCHOOL YEAR 6 PRELIMINARY EXAMINATION CANDIDATE NAME CLASS 6 CENTRE NUMBER S INDEX NUMBER H2 CHEMISTRY 9647/02 Paper 2 Structured Questions 13 September 2011 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 the 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. A Data Booklet is provided. Do not write anything on it. The number of marks is given in brackets [ ] at the end of each question or part question. At the end of the examination, fasten all your work securely together. For Examiner’s Use 1 2 3 4 5 Total ____________________________________________________________________________ This document consists of 18 printed pages.

River Valley High School 9647/02/PRELIM/11 [Turn over Preliminary Examination 2011 2 Answer all questions in the space provided. 1. Planning (P) John went on an excursion to a limestone cave in Gunung Mulu National Park, Sarawak. In there, he picked up a limestone rock and decided to investigate the percentage by mass of CaCO3 in this rock sample. When he was back in his school laboratory, he weighed the rock sample and the reading was 0.200 g. (a) 2H+ + CO3 2 CO2 + H2O Given the equation above, draw a labelled experimental setup of how collection of CO2 gas can be achieved. [3] (b) Given that the percentage by mass of CaCO 3 in the limestone rock sample is at least 60% and assuming that other substances in the rock sample are inert to acid, calculate the volume of 0.100 mol dm3 of HCl that should be used to react with the rock sample. Ar: Ca, 40.1; C, 12.0; O, 16.0; Assuming that the experiment is carried out under room temperature and pressure, 1 mole of gas occupies 24000 cm3 under these conditions. [2]

River Valley High School 9647/02/PRELIM/11 [Turn over Preliminary Examination 2011 3 (c) Using the information given in (a) and (b), calculate the volume of the apparatus needed for the collection of CO2 gas in this experiment. [2] (d) With the help of your diagram in (a), describe the procedure to find the percentage mass of CaCO 3 in the rock sample. Your plan should give a step-by-step description of the method, including the calculations to determine the percentage by mass of CaCO3. [3] ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………