JPJC 2023 Prelim P3 QP

© Jurong Pioneer Junior College [Turn Over NAME CLASS 22S JURONG PIONEER JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATION 2023 CHEMISTRY 9729/03 Higher 2 Paper 3 Free Response 13 September 2023 2 hour Candidates answer on the Question paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, class and index number in the spaces at the top of this page. Write in dark blue or black pen. You may use a 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 pages at the end of this booklet. The question number must be clearly shown. Section A Answer all questions. Section B Answer one question. Write the Question number of the Question you have attempted, in the box provided below. A Data Booklet is provided. The use of an approved scientific calculator is expected, where appropriate. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use 1 20 2 22 3 18 4 or 5 20 Penalty (delete accordingly) Lack 3sf in final answer –1 / NA Missing/wrong units in final ans –1 / NA Bond linkages –1 / NA Total 80 This document consists of 32 printed pages.

2 © Jurong Pioneer Junior College 9729/03/J2 PRELIMINARY EXAM/2023 Section A Answer all the questions in this section. 1 Carbon monoxide, CO, occurs in the exhaust gases of internal combustion engines. Other gases in the exhaust gases include oxides of nitrogen, NOx. For Examiner’s Use (a) CO and NO can be removed from the exhaust gases by a catalytic converter to form CO2 and N2. Construct a balanced equation for this reaction. [1] …………………………………………………………………………………………… (b) Explain why N 2 gas behaves more like an ideal gas than CO gas at 20.0 C and 101 kPa. [2] …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… (c) A mixture of carbon monoxide and hydrogen is known as synthesis gas . Synthesis gas is used as a feedstock for the manufacture of methanol. CO(g) + 2H2(g)  CH3OH(g) H = −91.0 kJ mol−1 A temperature of 550 K and pressure of 60 atm are used in this reaction with a catalyst. When the reaction reached equilibrium, a mixture of gases was extracted. It contained 364 g of carbon monoxide, 5 g of hydrogen, and 171 g of methanol. (i) Calculate the value of Kp for this reaction at 550 K. [3] (ii) Explain the effect of increasing temperature on the equilibrium yield of methanol. [1] …………