NJC Physical Chemistry Revision Part 2 with answers

Physical Chemistry Revision Part 2 No. Topic Questions Page Answers Page 1 Chemical Equilibrium 1-17 17-44 2 Acid Base Equilibrium 45-62 63-79 3 Solubility Equilibrium 80-91 91-101 4A Electrochemistry (Electrochemical Cells) 102-116 126-137 4B Electrochemistry (Electrolytic Cells) 117-121 137-142 4C Electrochemical and Electrolytic Cells 121-126 142-146 Copyright © National Junior College All Rights Reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording or any other information storage and retrieval system, without prior permission in writing from the copyright owner.

National Junior College SH2 H2 Chemistry 1 1) Chemical Equilibrium MCQ 1 Nitrogen dioxide decomposes on heating according to the following equation. 2NO2(g) 2NO(g) + O2(g) When 4 mol of nitrogen dioxide were put in a 1 dm 3 container and heated, the equilibrium mixture contained 0.8 mol of oxygen. What is the equilibrium constant, Kc, at the temperature of the experiment? A 0.8 × 0.82 2.42 B 0.8 × 1.62 2.42 C 0.8 × 0.82 42 D 0.8 × 1.62 42 2 If compound A is heated, it decomposes according to the equation: 2A(g) B(g) + C(g) The following diagram shows the progress of the reaction. Determine the value of equilibrium constant Kc. A 0.8 B 2.0 C 4.0 D 10.0 Concentration / mol dm-3 Time / hours

National Junior College SH2 H2 Chemistry 2 3 The key stage in the manufacture of sulfuric acid is the reaction between sulfur dioxide and oxygen to form sulfur trioxide. 2SO2(g) + O2(g) ⇌ 2SO3(g) When 0.50 mol of SO2 and 1.00 mol of O2 were reacted together in a container of volume 0.5 dm3, 0.30 mol of SO3 was present in the equilibrium mixture. What is the numerical value of the equilibrium constant, Kc, for the equilibrium reaction below? SO2(g) + 1 2O2(g) ⇌ SO3(g) A 0.66 B 1.15 C 1.32 D 1.63 4 Consider the following equilibrium: When Q2 is allowed to react with R 2 in a molar ratio of 2:1 at a total initial pressure of 3 atm, 20% of the equilibrium mixture is found to be Q2R. What is the equilibrium constant, Kp, of this reaction? A 0.0174 atm−1 B 0.0781 atm−1 C 0.194 atm−1 D 0.232 atm−1 5 The contact process is an important industrial reaction which produces sulfuric acid. One of the steps of the process involves the addition of excess oxygen to sulfur dioxide to produce sulfur trioxide gas in an equilibrium reaction: 2SO2(g) + O2(g) 2SO3(g) SO2(g) and O 2(g) were mixed in a 1:2 ratio and the mixture was kept at a constant pressure of 5 atm. At equilibrium, it was found that 30% of the sulfur dioxide was consumed. What is the numerical value of Kp of this reaction? A 0.0566 B 0.142 C 1.75 D 8.35

National Junior College SH2 H2 Chemistry 3 6 A 1:3 molar mixture of X2 and Y2 is heat