SRJC_2008 JC2 Prelims H1 Paper 2

© SRJC 2008 8872/02/Prelims/2008 [Turn Over SERANGOON JUNIOR COLLEGE General Certificate of Education Advanced Level Higher 1 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY 8872/02 Preliminary Examination 19 August 2008 Paper 2 2 hr Additional Materials: Data Booklet Writing Papers 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. SECTION A : Answer all questions in the space provided. SECTION B: Answer two questions on separate answer paper. 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. For Examiner’s Use Section A B5 B6 B7 This document consist of 18 printed pages and NO blank page

2 © SRJC 2008 8872/02/Prelims/2008 [Turn Over 1 Iron tablets containing iron ( II) sulphate can be used to s upplement the daily iron intake in diet. The Health Sciences Au thority had regulated that all commercially available iron tablets must contain 15 to 18% by mass of iron. (a) Acidified potassium manganate (VII), KMnO4, which oxidises iron (II) sulphate, is used to estimate the amount of iron (II) ions, Fe2+, present in Brand A iron tablet. 2.00 g of the iron tablet was dissolved in dilute acid and the volume of the solution was made up to 100 cm3 in a volumetric flask. A 10.0 cm3 portion of this solution was titrated against 2.50 x 10 -4 mol dm-3 of potassium manganate (VII) solution. 13.50 cm 3 of the manganate (VII) solution was required to completely oxidise the Fe2+ present. (i) Write the overall equation of the reaction between MnO4 - and Fe2+. (ii) Calculate the concentration of Fe 2+ in the 100 cm3 solution. (iii) Hence, state with reasoning if the Brand A iron tablet meet s the regulation stated by the Health Sciences Authority. [4]

3 © SRJC 2008 8872/02/Prelims/2008 [Turn Over (b) Write the electronic configurations of Fe and Fe2+ ion. Fe: Fe 2+: [ 1 ] (c) On the diagram below, show and la bel clearly how the beams of the following particles are deflected when subjected to an electric field. (i) e l e c t r o n (ii) proton (iii) Fe atom You should relate clearly the magnitude and the direction of deflection of each beam to the