2022 MI H2 Chem Prelim Paper 3 - Question

Class Adm No Candidate Name: This question paper consists of 23 printed pages and 1 blank page. 2022 Preliminary Examination Pre-University 3 H2 CHEMISTRY 9729/03 Paper 3 Free Response 19 September 2022 2 hours Candidates answer on the Question Paper. Additional materials: Data Booklet READ THESE INSTRUCTIONS FIRST Do not turn over this question paper until you are told to do so. Write your name, class and admission number in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions in the spaces provided on the Question Paper. If additional space is required, you should use the page at the end of this booklet. The question number must be clearly shown. Section A Answer all questions. Section B Answer one question. A Data Booklet is provided. The use of an approved scientific calculator is expected, where appropriate. 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. Question A B Total 1 2 3 4 5 / 6 Marks 16 12 18 14 20 80

2 Section A Answer all the questions in this section. 1 (a) The Bunsen cell is an electrochemical cell built to provide electrical energy. It consists of a zinc anode in dilute sulfuric acid, separated by a salt bridge from a carbon cathode in dilute nitric acid. Nitrogen dioxide, NO 2, is the only gas formed from the reaction. At the anode, zinc decreases in size during the reaction. (i) Draw a fully labelled diagram of the Bunsen cell. [3] (ii) Use data from the Data Booklet to construct an overall equation for the reaction. [2] (iii) Calculate the cell potential, E, for the reaction. [1] (iv) The experimental E of the Bunsen cell is +1.9 V. Use ideas about reversible reactions to suggest why the experimental E may differ from the calculated value in (iii). [2] ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….………………………………………………………………………………. ……….………….……………………………………………………………………………….

3 [Turn over (b) Nitrogen dioxide, NO2, and dinitrogen tetroxide, N