SAJC Prelim P2

ST. ANDREW’S JUNIOR COLLEGE Higher 1 PRELIMINARY EXAMINATION 2009 Name Class CHEMISTRY PAPER 2 Candidates answer Section A on the Question Paper. 8872/ 02 15 September 2009 2 hours Additional Materials: Writing paper 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 working. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A Answer all questions. Section B Answer any two questions on separate writing paper. A Data Booklet is provided. At the end of the exam, 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 Section A / 40 B9 B10 B11 Total / 80 This paper consists of 16 printed pages and 1 blank page.

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3 Section A Answ er all questions. 1 The use of the Data Booklet is relevant to this question. (a) (i) Define relative atomic mass. [1] (ii) Gallium is in Group III and is found below aluminium in the Periodic Table. Gallium has 2 isotopes. One of the isotopes, 69Ga has a relative abundance of 64.0%. Calculate the relative isotopic mass of the other gallium isotope, to the nearest whole number. [1] (b) Acidified potassium manganate(VII) oxidises ethanedioic acid, H2C2O4 to form carbon dioxide gas according to the following ionic equation: C2O4 2-  2CO2 + 2e 1.07 g of impure sample of H2C2O4 was made up to 250 cm3 of solution. 25.0 cm3 of this solution reacted completely with 25.60 cm3 of 0.02 mol dm-3 acidified KMnO4 solution. (i) Write an overall ionic equation for the reaction between H2C2O4 and KMnO4. [1] [Turn Over

4 1 (b) (ii) Hence, determine the percentage purity of the ethanedioic acid. [2] [Total: 5 ] 2 The first 8 ionisation energies of an element, W, is shown in the table below. Electron 1 2 3 4 5 6 7 8 Ionisation energy/ kJ mol -1 572 890 1250 2249 4973 6152 9945 11012 (a) Deduce which group element W belongs to. Explain your answer. [2] (b) (i) Suggest the formula of the oxide of W and predict the type of bonding present in the oxide of W. [1] Formula: __________ Type of bonding: ______________ (ii) Suggest a pH value for the resulting solution obtained when the oxide of W is dissolved in water. [1] [Total: 4]

5 3 Oil of wintergreen is a common active ingredient in muscle rubs. It has the following structure. C O O CH3 2 OH 1 (a) State the type of hybridisation of the carbon atoms, C1 and C2. [2] C1: __________ C2:___________ (b) State the shape and the bond angle around carbons C1 and C2. [2] Carbon Shape Bond angle C