HCI Prelim_H2_CHEM_P3

This document consists of 11 printed pages. HWA CHONG INSTITUTION C2 Preliminary Examinations Higher 2 CANDIDATE NAME CT GROUP 15S CENTRE NUMBER INDEX NUMBER CHEMISTRY Paper 3 Free Response Candidates answer on separate paper. Additional Materials: Answer Paper Data Booklet 9647/03 19 September 2016 2 hours INSTRUCTIONS TO CANDIDATES Write your name and class on all the work you hand in. Write in dark blue or black pen. 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 any four questions. Begin each question on a new piece of paper. A Data Booklet is provided. You are reminded of the need for good English and clear presentation in your answers. 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. Write down the question numbers for the questions attempted on the cover page provided.

2 © Hwa Chong Institution 2016 9647 / 03 / C2 Prelim 2016 Answer any four questions. 1 (a) Suggest and explain how the boiling points of 1-chlorobutane and 1-bromobutane differ from each other. [2] (b) (i) Define the term standard enthalpy change of combustion. [1] (ii) Use of the Data Booklet is relevant to this question. In an experiment to determine the enthalpy change of combustion of bromobutane, a quantity of the fuel was burnt underneath a copper can containing 200 g of water. It was found that the temperature rose by 45.0 C after 2.35 g of bromobutane had been burnt. The heat transfer was known to be only 80% efficient. Calculate the enthalpy change of combustion of the bromobutane. Ignore the heat capacity of the copper can. [2] (c) An experiment was set up to study the reaction between 2 -bromo-3-methylbutane and sodium hydroxide. The reagents used were FA1, containing 0.0100 mol dm –3 of 2-bromo-3-methylbutane and FA2, containing 0.0100 mol dm –3 NaOH. In each experiment, the reagents were dissolved in a suitable solvent to ensure good mixing. The results are recorded in the table below. Expt Volume of FA1 / cm3 Volume of FA2 / cm3 Volume of solvent / cm3 Rate / mol dm–3 s–1 1 10.0 30.0 60.0 7.40 x 10-7 2 5.0 20.0 25.0 9.86 x 10-7 3 10.0 5.0 35.0 4.93 x 10-7 (i) Use the data in the table to deduce the order of reaction with respect to 2-bromo-3-methylbutane and sodium hydroxide. Hence, write a rate equation for this reaction. [3] (ii) With reference to your ans