NYJC H2 Chem 2013 Prelim P2 QP

H2 Chemistry 9647/02 NYJC J2/2013 Prelim [Turn Over NANYANG JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CLASS TUTOR’S NAME CHEMISTRY 9647/02 Paper 2 Structured Questions 23 September 2013 2 hours Candidates answer on the Question Paper. Additional Materials: 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. Answer all questions in the spaces provided. 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. For Examiner’s Use 1 /12 2 /22 3 /10 4 /18 5 /10 Total /72 This document consists of 17 printed pages. 23

2 H2 Chemistry 9647/02 NYJC J2/2013 Prelim For Examiner's Use Answer all questions in the spaces provided. 1 Planning (P) Acids can be classified in terms of t heir basicity depending on the number of protons that can be donated to a base. A st udent is investigating the basicity of a solution of 0.80 mol dm-3 acid, A, using just the acid and sodium hydroxide of the same concentration. He conducted two ex periments by mixing different volumes of A and sodium hydroxide, and taking the temperature rise for each experiment. (a) Based on the definition of the enthalpy change of neutralisation (∆Hn) and his results, deduce the basicity of acid A. Experiment Volume of acid Volume of NaOH ∆T /oC 1 40 20 3.6 2 20 40 7.2 ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… [2] (b) (i) The temperature rise of the reaction can be det ermined graphically by measuring how the temperature changes with time. You are to plan an experiment to determine the ∆H n between a solid sample of A and sodium hydroxide. You are provided with a solid sample of A (M r = 174) and sodium hydroxide solution of 0.80 mol dm-3. In your plan, you should give:  details including calculations to determine the quantities of the reactants to be used;  choice of apparatus (You may use appar atus normally found in the school laboratory.);  the essential details for obtaining t he graph of temperature against time in order to determine the temperature rise;  table(s) of readings to taken. 24

3 H2 Chemistry 9647/02 NYJC J2/2013 Prelim [Turn Over For Examiner's Use Calculations: Procedure: …………….………………………………………………………