NJC 2023 Gases Lecture Notes Student Version

National Junior College SH1 H2 Chemistry 1 The Gaseous State Content • Ideal gas behaviour and deviations from it • pV = nRT and its use in determining a value for Mr • Dalton’s Law and its use in determining the partial pressures of gases in a mixture Learning Outcomes required for H2 (9729) Chemistry: Candidates should be able to • state and use the general gas equation pV = nRT in calculations, including the determination of Mr • use Dalton’s Law to determine the partial pressure of gases in a mixture • state basic assumptions of the kinetic theory as applied to an ideal gas • explain qualitatively in terms of intermolecular forces and molecular size: ➢ the conditions necessary for a real gas to approach ideal behaviour; ➢ the limitations of ideality at very high pressures and very low temperatures References: ➢ Chemistry in Context by G Hill & J Holman ➢ Chemistry for Advanced Level by Peter Cann & Peter Hughes Instructions to Students Period Activities 13 March – 9 April Self-Directed Learning Access: 1) Google classroom for Checkpoint suggested answers 2) SLS lesson - “Ideal and Real Gases” 3) SLS lesson - “Ideal Gas Laws” 10 April – 14 April 1 Tutorial for topic discussion 17 April – 21 April Class Test Copyright © 2023 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 SH1 H2 Chemistry 2 1 Introduction 1.1 The three states of matter Physical State Solid Liquid Gas Attractive forces between particles Strong Intermediate Weak Motion of particles Vibrate and rotate about fixed positions (no translation motion) Move freely throughout liquid (vibrate, rotate and translate) Move freely within the container (vibrate, rotate and translate) Space between particles Negligible Small Large Order of Packing of Particles Regular packing in crystals Loose clusters of particles No order; far apart Comparing Properties of Solids, Liquids and Gases Volume Fixed Fixed Particles will spread evenly throughout any container, thus volume is indefinite and shape is that of the container. Shape Fixed Takes the shape of the container but may not occupy it completely Relative Density High Moderate Low Relative Compressibility Negligible or almost nil Very slight Very easily compressed 1.2 Relationship between the three states of matter

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