Edexcel a level chemistry 1 by hunt, andrew curtis

EDEXCEL A LEVEL CHEMISTRY Graham Curtis Andrew Hunt Graham Hill 807466_FM_Edexcel Chemistry_i-vi.indd 07/04/2015 11:46 Photo credits: p Karina Baumgart – Fotolia; blueskies9 – Fotolia (inset); p image originally created by IBM Corporation; p Andrew Lambert Photography/Science Photo Library (both); p. 6 theartofphoto – Fotolia; p 10 Gayvoronskaya_Yana/Shutterstock; p 12 t Science Source/Science Photo Library; b Sheila Terry/Science Photo Library; p 15 Jason Hawkes/Corbis; p 16 Graham J Hills/ Science Photo Library; p.23 Gilbert Iundt; Jean-Yves Ruszniewski/TempSport/Corbis; p 24 Dept of Physics, Imperial College/Science Photo Library; p 39 Philippe Plailly/Eurelios/Science Photo Library; p 40 t marcel – Fotolia, b Monkey Business – Fotolia; p 41 Andrew Lambert Photography/Science Photo Library; p 43 Ruddy Gold/age fotostock/SuperStock; p 49 Andrew Lambert Photography/ Science Photo Library; p 59 Charles D Winters/Science Photo Library; p 60 nico99 – Fotolia; p. 65 marcaletourneux – Fotolia; p 69 jurra8 – Fotolia; p 71 Stuart Franklin/Getty Images; p 72 bl James King-Holmes/Science Photo Library, br Alfred Pasieka/Science Photo Library; p 75 branex – Fotolia; p 81 Miredi – Fotolia; p 84 Andrew Lambert Photography/Science Photo Library; p. 94 Martyn F Chillmaid/Science Photo Library; p 95 Andrew Lambert Photography/Science Photo Library; p 96 Lawrence Migdale/Science Photo Library; p 98 Andrew Lambert Photography/Science Photo Library (all); p 99 Andrew Lambert Photography/Science Photo Library; p 101 tr Martyn F Chillmaid/Science Photo Library, cr macropixel – Fotolia, br Joel Arem/Science Photo Library, bl Andrew Lambert Photography/Science Photo Library; p 105 Javier Trueba/Msf/Science Photo Library; p. 106 l Photographee.eu – Fotolia, r Alfred Pasieka/Science Photo Library; p 108 l Andrew Lambert Photography/Science Photo Library, c sciencephotos/Alamy, r Andrew Lambert Photography/Science Photo Library; p 109 Andrew Lambert Photography/Science Photo Library; p 112 Andrew Lambert Photography/Science Photo Library (both); p 114 Martyn F Chillmaid/Science Photo Library; p 116 Christophe Schmid – Fotolia; p 120 Martyn F Chillmaid (both); p 131 Geoff Tompkinson/Science Photo Library; p 143 Saturn Stills/Science Photo Library; p 150 c Mint Images – Tim Robbins/ Science Photo Library, bl Michelle Albers – Fotolia; p 154 Graham Curtis; p 171 michelaubryphoto – Fotolia; p 172 Alvey & Towers Picture Library/Alamy; p 175 Andrew Lambert Photography/Science Photo Library (all); p 181 Tony Craddock/Science Photo Library; p 183 David R Frazier/Science Photo Library; p 188 Lenscap/Alamy; p 196 Green Stock Media/Alamy; p 198 papa1266 – Fotolia; p. 202 Thomas Trotscher/Getty Images; p 211 Agencja Fotograficzna Caro/Alamy; p 212 Roger Job/ Reporters/Science Photo Library; p 218 Andrew Lambert Photography/Science Photo Library; p. 219 Andrew Lambert Photography/Science Photo Library; p 225 Gareth Price; p 229 Amy Sinisterra/AP/ Press Association Images; p 238 Hodder; p 239 Phil Degginger/Alamy; p 262 tl Clive Freeman, The Royal Institution/Science Photo Library, b Israel Sanchez/epa/Corbis; p 274 bl albinoni – Fotolia, br Santi Rodríguez – Fotolia; p 275 Andrew Lambert Photography/Science Photo Library b = bottom, c = centre, l = left, r = right, t = top Acknowledgement Data used for the mass spectra in Figures 7.4 and 7.6 and for the IR spectra on page 235 come from the SDBS of the National Institute of Advanced Industrial Science and Technology Although every effort has been made to ensure that website addresses are correct at time of going to press, Hodder Education cannot be held responsible for the content of any website mentioned in this book It is sometimes possible to find a relocated web page by typing in the address of the home page for a website in the URL window of your browser Hachette UK’s policy is to use papers that are natural, renewable and recyclable products and made from wood grown in sustainable forests The logging and manufacturing processes are expected to conform to the environmental regulations of the country of origin Orders: please contact Bookpoint Ltd, 130 Milton Park, Abingdon, Oxon OX14 4SB Telephone: +44 (0)1235 827720 Fax: +44 (0)1235 400454 Lines are open 9.00a.m.–5.00p.m., Monday to Saturday, with a 24-hour message answering service Visit our website at www.hoddereducation.co.uk © Graham Curtis, Andrew Hunt, Graham Hill 2015 First published in 2015 by Hodder Education, An Hachette UK Company 338 Euston Road London NW1 3BH Impression number 10 Year 2019 2018 2017 2016 2015 All rights reserved Apart from any use permitted under UK copyright law, no part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or held within any information storage and retrieval system, without permission in writing from the publisher or under licence from the Copyright Licensing Agency Limited Further details of such licences (for reprographic reproduction) may be obtained from the Copyright Licensing Agency Limited, Saffron House, 6–10 Kirby Street, London EC1N 8TS Cover photo © hoboton – Fotolia Typeset in 11/13 Bembo Std by Aptara, Inc Printed in Italy A catalogue record for this title is available from the British Library ISBN 978 147 1807466 807466_FM_Edexcel Chemistry_i-vi.indd 08/04/15 9:00 pm Contents Acknowledgements Get the most from this book Introduction ii iv vi Prior knowledge 1 Atomic structure and the periodic table 12 Bonding and structure 38 Redox I 81 Inorganic chemistry and the periodic table 94 Formulae, equations and amounts of substance 119 6.1 Introduction to organic chemistry 150 6.2 Hydrocarbons: alkanes and alkenes 171 6.3 Halogenoalkanes and alcohols 202 Modern analytical techniques I 225 Energetics I 237 Kinetics I 262 10 Equilibrium I 274 Appendix 807466_FM_Edexcel Chemistry_i-vi.indd A1 Mathematics in (AS) chemistry 286 A2 Preparing for the exam 301 Index QR codes The periodic table of elements 307 312 314 07/04/2015 11:46 Get the most from this book Welcome to the Edexcel A level Chemistry Student’s Book! This book covers Year of the Edexcel A level Chemistry specification and all content for the Edexcel AS Chemistry specification The following features have been included to help you get the most from this book Tips These highlight important facts, common misconceptions and signpost you towards other relevant topics Key terms and formulae These are highlighted in the text and definitions are given in the margin to help you pick out and learn these important concepts Test yourself questions These short questions, found throughout each chapter, are useful for checking your understanding as you progress through a topic Examples Examples of questions and calculations feature full workings and sample answers iv Get the most from this book 807466_FM_Edexcel Chemistry_i-vi.indd 07/04/2015 11:46 Activities and Core practicals These practical-based activities will help consolidate your learning and test your practical skills Edexcel's Core practicals are clearly highlighted In this edition the authors describe many important experimental procedures to conform to recent changes in the A level curriculum Teachers should be aware that, although there is enough information to inform students of techniques and many observations for exam purposes, there is not enough information for teachers to replicate the experiments themselves, or with students, without recourse to CLEAPSS Hazcards or Laboratory worksheets which have undergone a risk assessment procedure Exam practice questions You will find Exam practice questions at the end of every chapter These follow the style of the different types of questions you might see in your examination and are colour coded to highlight the level of difficulty Test your understanding even further with Maths questions and Stretch and challenge questions Dedicated chapters for developing your Maths and Preparing for your exam are also included in this book Get the most from this book 807466_FM_Edexcel Chemistry_i-vi.indd v 07/04/2015 11:46 Introduction vi Introduction 807466_FM_Edexcel Chemistry_i-vi.indd This book is an extensively revised, restructured and updated version of Edexcel Chemistry for AS by Graham Hill and Andrew Hunt We have relied heavily on the contribution that Graham Hill made to the original book and are most grateful that he has encouraged us to build on his work The team at Hodder Education, led initially by Hanneke Remsing and then by Emma Braithwaite, has made an extremely valuable contribution to the development of the book and the website resources In particular, we would like to thank Abigail Woodman, the project manager, for her expert advice and encouragement We are also grateful for the skilful work on the print and electronic resources by Anne Trevillion We have grouped each set of ‘Exam practice’ questions broadly by difficulty In general, a question with is straightforward and based directly on the information, ideas and methods described in the chapter Each problem-solving part of the question typically only involves one step in the argument or calculation A question with is a more demanding, but still structured, question involving the application of ideas and methods to solve a problem with the help of data or information from this chapter or elsewhere Arguments and calculations typically involve more than one step The questions marked by are hard and they may well expect you to bring together ideas from different areas of the subject In these harder questions you may have to structure an argument or work out the steps required to solve a problem In the earlier chapters, you may well decide not attempt the questions with until you have gained wider experience and knowledge of the subject Practical work is of particular importance in A Level chemistry Each of the Core Practicals in the specification features in the main chapters of this book with an outline of the procedure and data for you to analyse and interpret Throughout the text there are references to Practical skills sheets which can be accessed via www.hoddereducation.co.uk/EdexcelAChemistry1 Sheets to provide general guidance, and the remainder provide more detailed guidance for the Core Practicals Practical skills for advanced chemistry Assessing hazards and risks Researching and referencing Making measurements Identifying errors and estimating uncertainties Measuring chemical amounts by titration Analysing inorganic unknowns Synthesising organic liquids Analysing organic unknowns 10 Measuring enthalpy changes You will need to refer to the Edexcel Data booklet when answering some of the questions in this book This will help you to become familiar with the booklet This is important because you will need to use the booklet to find information when answering some questions in the examinations You can download the Data booklet from the Edexcel website It is part of the specification The booklet includes the version of the periodic table that you use in the examinations Andrew Hunt and Graham Curtis August 2014 07/04/2015 11:46 Prior knowledge Working like a chemist Chemistry is about understanding the material world Chemists develop their explanations by observing the properties of substances and looking at patterns of behaviour (Figure 1) They devise theories and models that can be used in chemical analysis and synthesis Figure Aspirin is probably the commonest medicine in use The bark of willow trees was used to ease pain for more than 2000 years Early in the twentieth century, chemists extracted the active ingredient from willow bark Their understanding of patterns in the behaviour of similar compounds enabled them to synthesise aspirin Tip This first chapter surveys the main themes of chemistry and indicates how you will be learning more about chemistry during your A Level course The chapters in this book build on what you already know about chemistry The text and ‘ Test yourself ’ questions in the early part of each chapter can help you to check on what you have learned before and what you need to understand at the start of each topic Looking for patterns in chemical behaviour Part of being a chemist involves getting a feel for the way in which chemicals behave Chemists get to know chemicals just as people get to know their friends and family They look for patterns in behaviour and recognise that some of the patterns are familiar For example, the elements sodium and potassium are both soft and stored under oil because they react so readily with air and water; copper sulfate is blue, like other copper compounds By understanding patterns, chemists can design and make plastics like polythene and medicines like aspirin Working like a chemist 807466_00_Edexcel Chemistry_001-011.indd 1 28/03/2015 07:42 Tip Test yourself The periodic table links together many of the key patterns of behaviour of elements You will extend your knowledge of the periodic table in Chapter You will also make a detailed study of patterns in the properties of the elements and compounds in some of the periodic table groups in Chapter Remind yourself of some patterns in the ways that chemicals behave 1 What happens when a more reactive metal (such as zinc) is added to a solution in water of a compound of a less reactive metal (such as copper sulfate)? 2 What forms at the negative electrode (cathode) during the electrolysis of a solution of a salt? 3 What happens on adding an acid (such as hydrochloric acid) to a carbonate (such as calcium carbonate)? What sodium chloride, sodium bromide and sodium iodide look like? Discovering the composition and structure of materials Tip Theories of structure and bonding are key to understanding the properties of materials You will extend your knowledge of these ideas when you study Chapter Chapter shows how measuring energy changes can provide evidence of the nature and strength of chemical bonds New materials exist only because chemists understand how atoms, ions and molecules are arranged in different materials, and about the forces which hold these particles together Thanks to this knowledge, people can enjoy fibres that breathe but are waterproof, plastic ropes that are 20 times stronger than similar ropes of steel and metal alloys which can remember their shape Understanding the structure and bonding of materials is a central theme in modern chemistry Fundamental to this is an understanding of how the atoms, molecules or ions are arranged in different states of matter (Figure 2) Particles in a solid are packed close together in a regular way The particles not move freely, but vibrate about fixed positions The particles in a liquid are closely packed but are free to move around, sliding past each other In a gas the particles are spread out, so the densities of gases are very low compared with solids and liquids The particles move rapidly in a random manner, colliding with other particles and the walls of the container Pressure is caused by particles hitting the walls Lighter particles move faster than heavier ones Figure The arrangements of particles in solids, liquids and gases Prior knowledge 807466_00_Edexcel Chemistry_001-011.indd 28/03/2015 07:42 Explaining and controlling chemical changes Four key questions are at the heart of many chemical investigations ● How much? – How much of the reactants is needed to make a product, how much of the product is produced, and how much energy is needed? ● How fast? – How can a reaction be controlled so that it goes at the right speed: not too fast and not too slow? ● How far? – Do the chemicals react completely, or does the reaction stop before all the reactants have turned into products? If it does, what can be done to get as big a yield as possible? ● How reactions occur? – Which bonds between atoms break and which new bonds form during a reaction? Tip Chapters and show you how chemists answer the question ‘How much?’ The questions ‘How fast?’ and ‘How far?’ are the focus of Chapters and 10 Understanding how reactions occur is a feature of organic chemistry and so the study of reaction mechanisms is explored in the three parts of Chapter Developing new techniques and skills Chemistry involves doing things as well as gaining knowledge and understanding about materials Chemists use their thinking skills and practical skills to solve problems One of the frontiers of today’s chemistry involves nanotechnology, in which chemists work with particles as small as individual atoms (Figure 3) Increasingly, chemists rely on modern instruments to explore structures and chemical changes They also use information technology to store data, search for information and to publish their findings Analysis and synthesis A vital task for chemists is to analyse materials and find out what they are made of When chemists have analysed a substance, they use symbols and formulae to show the elements it contains Symbols are used to represent the atoms in elements; formulae are used to represent the ions and molecules in compounds Analysis is involved in checking that water is safe to drink and that food has not been contaminated People may worry about pollution of the environment, but without chemical analysis they would not know about the causes or the scale of any pollution Chemists have devised many ingenious methods of analysis Spectroscopy is especially important At first spectroscopists just used visible light, but now they have found that they can find out much more by using other kinds of radiation such as ultraviolet and infrared rays, radiowaves and microwaves Chemistry is also about making things Chemists take simple chemicals and join them together to make new substances This is synthesis On a large scale, the chemical industry converts raw materials from the earth, sea and air into valuable new products A well-known example is the Haber process which uses natural gas and air to make ammonia Ammonia is the chemical needed to make fertilisers, dyes and explosives On a smaller scale, chemical reactions produce the specialist chemicals used for perfumes, dyes and medicines Figure In the 1990s, two scientists working for IBM cooled a nickel surface to −269 °C in a vacuum chamber Then they introduced a tiny amount of xenon so that some of the xenon atoms stuck to the nickel surface Using a special instrument called a scanning tunnelling microscope, the scientists were able to move individual xenon atoms around on the nickel surface and construct the IBM logo Each blue blob is the image of a single xenon atom Tip You will be developing your practical skills and understanding of practical chemistry during your A Level course Most chapters in this book include activities and core practicals with results and data to analyse General guidance on practical work can be accessed via the QR code for Chapter on page 312 Working like a chemist 807466_00_Edexcel Chemistry_001-011.indd 3 28/03/2015 07:42 In each of the first three 3D representations, the two normal lines represent covalent bonds in the plane of the paper The solid wedge represents a bond coming out of the paper, while the hashed bond represents a bond going into the paper H H C C Cl Cl H Cl Cl C H Cl H Cl H Rotating the structures should demonstrate that they are all the same molecule But drawing 3D structures is fairly difficult, so molecules are sometimes represented with normal line or dotted line bonds, but still with an attempt at 3D structures as shown here H H C H Cl Cl Cl C Cl H C Cl H Cl H More commonly, molecules are shown as flat structures (as below) In this case, chemists have to remember that the bond angles shown as 90° or 180° are all the tetrahedral angle, 109.5° Although these look like flat crosses, the four bonds are arranged tetrahedrally around the central carbon atom in exactly the same way as in the six structures above H H H C Cl Cl Cl C H Cl Cl H C H Cl The shapes of molecules with a central atom surrounded by between and pairs of electrons are discussed in Section 2.4, together with the effect of the extra repulsion if some of the pairs are lone pairs You should learn the five common molecule shapes and try to recognise them whenever they appear So, the trigonal planar arrangement of BF3, with bond angles of 120°, is also seen in the bonding around the carbons in ethene or in a carbocation (Section 6.2.10) or the carbonate ion, CO32– The tetrahedral arrangement is seen in every alkane but also in the ammonium ion, NH4+, and the sulfate ion, SO42– The trigonal bipyramid structure is seen in the transition state when nucleophilic substitution occurs at a primary halogenoalkane (SN2) (Chapter 6.3) The bond which is forming, the bond which is breaking, plus the three unchanged bonds are as far apart from each other as possible – the same arrangement as in a molecule of PF5 – so there are bond angles of 120° and 90° in the structure 300 A1 Mathematics in (AS) chemistry 807466_app01_Edexcel Chemistry_286-300.indd 300 28/03/2015 12:14 A2 Preparing for the exam A2.1 Revision Understanding what you need to know and Your revision should be systematic and based on a copy of the Edexcel A Level specification The specification tells you what you have to know, understand and be able to However, the language is very concise and mainly written for teachers This textbook has been written to cover the specification The chapters are in the same order as the specification, so, if you are puzzled by a statement in the content, look for guidance in the related chapter in this book The specification includes a table showing the assessment objectives for the course This table may seem rather technical and unimportant, but it will help you to understand what you have to be able to when answering questions in examinations There are three assessment objectives: AO1, AO2 and AO3 In the AS exams at the end of the first part of the Edexcel course, about 35−37% of the marks test your knowledge and understanding of the content This is AO1 There will be questions asking you to show that you can recall facts, patterns and principles There will also be questions asking you to translate information from one form to another, carry out simple calculations of a kind you have seen before, and to solve problems in familiar contexts About 41−43% of the marks test AO2, which covers your ability to apply your knowledge and understanding of scientific ideas, processes, techniques and procedures in a range of contexts, which could be familiar or unfamiliar: ● ● ● ● in a theoretical context in a practical context when handling qualitative data when handling quantitative data Then about 20−23% of the marks are allocated to AO3, which covers your ability to analyse, interpret and evaluate scientific information, ideas and evidence which you have not seen before This requires you to be able to: ● ● make judgements and reach conclusions develop and refine practical design and procedures So, you can see that it is very important that you have the confidence to apply your chemical understanding to unfamiliar situations in which you may have to interpret new sets of data and information, including that presented A2.1 Revision 807466_app02_Edexcel Chemistry_301-306.indd 301 301 30/03/2015 12:23 in tables, charts or graphs This confidence comes with practice You need to be able to link together ideas from different fields of chemistry to offer explanations or construct arguments Tip See the Practical skills sheets, accessed via the QR codes on pages 312 and 313, for more guidance on practical procedures, measurements and the evaluation of experimental data Chemistry is a practical subject and high-scoring students not only develop good technical skills in the laboratory, but also develop a strategic sense of the ways that experiments are planned and carried out to give meaningful results Examination questions will ask you to describe how experiments were carried out and what happened; they will also ask you to explain the rationale for the procedures You will also be asked to interpret the results of experiments qualitatively and quantitatively, and to draw valid conclusions from data, taking into account measurement uncertainty Understanding the course as a whole Some questions in the examinations expect you to bring together your knowledge and understanding of different areas of chemistry, applying them in contexts that may be new to you This is sometimes called synoptic assessment The term ‘synoptic’ implies that you have an understanding of the course as a whole, and an appreciation of how the different topics in the course hang together and relate to each other So, any synoptic questions require you to work across different parts of the specification and to show that you can draw on ideas and information from different topics to answer questions or solve problems Revision notes Check that you have your own notes on all sections of the specification Organise your notes with clear titles and subheadings Highlight key points in colour Include mnemonics if you find them helpful, such as: ● OIL RIG (oxidation is loss, reduction is gain MEPrB (methane, ethane, propane, butane) ● ALSUB (axes, labels, scales, units, points) ● Flow diagrams can be helpful in giving you an overview of organic chemistry Alkenes Ketones Alcohols Alkanes Halogenoalkanes Nitriles Amines Aldehydes Carboxylic acids Figure A2.1 Relationships between series of organic compounds Make a copy of the diagram, then add examples with formulae and label the arrows to show how one functional group can be converted to another 302 A2 Preparing for the exam 807466_app02_Edexcel Chemistry_301-306.indd 302 30/03/2015 12:23 Active revision You need to make your revision active, so that you maintain concentration and really test that you understand the key points, while developing the necessary skills For each revision topic, try writing the title of a topic in the centre of a sheet of paper Then use the definitions and explanations in the main part of this book to help you build up a mind map or concept map to show how the ideas in the topic link together INTERM OL EC CO G URAL AT N TIC S S N I A Y H C N THE N CO VALENT BO EMPIR IC A MOLEC ULA ST R FORMU RUCTURAL L M OL ECULE S A ISOMERISM OR S G REFIN C H E M I ST R Y TE PR ING ACTICA RADICALS FREE Y N OXYGE HOLS CO L CO MPOUNDS A O AR XY BONYL LIC CO MPOUNDS ACI S D FUELS ET ROCHEMICALS L ANALYSIS YN S L RO HYD HOMOLYTIC HE YS IS T IO NIC O IES ES KAN AL BONS AL R A KENES OC DR EN P ADDITION CHANGING MOLE CU LE S IO N IO N SUBSTITUT N REACT S –BASE T Y P E D I C A A N I B X ELIM OND O BREAKIN RED G M HO US GO LO R SE DS UN PO CARB ) G LON M C AL UR STRUCT AE – tran s NG DI L (cis E–Z HALO DO UBLE H LE R ULA SING THESIS R O LY T I C ELECTROPHIL ES N U CL EOPHILE S Figure A2.2 The start of a mind map for introductory organic chemistry Suppose you are revising the chemistry of the halogens Have a pile of scrap paper to hand and a pencil Now, as you read, make jottings, small lists, summary phrases, write equations, sketch diagrams and practise labelling them Now tear up the paper, close the textbooks and notes, and write out those lists, equations, diagrams and so on Then check to see whether you have remembered correctly When it comes to learning the reactions of a family of organic compounds such as the alcohols, consider using a set of cards Write the equation for each alcohol reaction you have to know on one side of the card Write the names of the reactants and the conditions for the reaction on the other side Now you can use the cards for revision Look at one side of the card and try to recall what is on the other side Similarly, test yourself using the expanded glossary available online with this textbook Tip Learn key definitions thoroughly Even top candidates frequently lose marks by missing out key words when asked to state what is meant by chemical terms Use the online glossary to help you Practise calculations with the help of worked examples Even if you have answered all the ‘Test yourself ’ questions in this book, it is worth working through them again, including the calculations, checking your responses with the answers provided online One of the key characteristics of a high-scoring candidate is the ability to carry out complex calculations, setting out the working step by step and including the correct symbols and units The worked examples in this textbook show you how to this Among the important calculations are those to work out titration results and thermochemistry calculations A2.1 Revision 807466_app02_Edexcel Chemistry_301-306.indd 303 303 30/03/2015 12:23 A2.2 Exam technique Past papers, mark schemes and examiners’ reports Look at past papers and practise answering the questions Some topics in the specification are so important that they are tested in most years with only very minor differences in emphasis and phrasing of questions It is because so many questions on some topics appear to be the similar year after year, that you must read the questions with the greatest of care to note the particular emphasis, and the precise nature of a question Looking at some past mark schemes can be helpful, but you need to bear in mind that they are mainly intended to help examiners give marks accurately, so they are presented very concisely and not include full answers However, the mark schemes for longer questions will show you what examiners are looking for when there are 3–6 marks for part of a question For some questions examiners expect you to write at greater length, drawing together and organising relevant material No marks are allocated for the plan you sketch out before writing your answer, but making a plan helps you to write a well organised answer with examples and so leads to better marks Examiners’ reports have traditionally been written for teachers, but increasingly they include information that students find helpful You can download the reports from the Edexcel website You will find that the report on a particular examination paper includes sample answers from students, together with comments and tips from the examiners Working through some of these reports will show you how to answer questions in the ways that gain most marks, and how to avoid common errors One of the most useful revision activities is to answer the questions in past examination papers and then to check your answers against the published mark scheme Question types The Edexcel examination papers consist of a series of structured questions Each question is set in a particular chemical context If the context is familiar, it may just be introduced by a short sentence, such as: ‘This question is about Group and enthalpy changes.’ However, there are other questions which start with much more information and data For example, there might be a summary of the procedure for an experiment, followed by some sample results Examiners not include information that you not need It is essential that you read the introduction to a question very carefully because you need it to answer the parts of the question Sometimes the introductory information at the start of a question will seem strange This is not because the examiner has made a mistake or your teacher has failed to cover some part of the specification As shown by the assessment objectives, the skills being tested in the examinations include your ability to apply your knowledge to unfamiliar situations You can be confident that the 304 A2 Preparing for the exam 807466_app02_Edexcel Chemistry_301-306.indd 304 30/03/2015 12:23 examiner has chosen a context and given data that you can be expected to make sense of using the chemistry that you have learned during the course Within the structured questions there are three main question types: multiple-choice questions, short-answer questions and questions asking for a longer answer Multiple-choice questions Multiple-choice questions can seem deceptively simple, because you are given four choices and have to choose one of them Sometimes they test your knowledge of a basic idea and, if you know the answer, you will be able to answer the question quickly However, some questions require careful thinking and may involve a calculation If a multiple-choice question involves a calculation you should not try to it in your head Write down your working in rough using a blank part of the question paper As always, you need to read the questions carefully, especially if the words ‘not’ or ‘never’ are included in the working A questions which includes ‘not’ can be confusing as in: ‘Which substance is not a product of the incomplete combustion of hexane?’ You have to pick the one of the four options that is not produced in the reaction Tip In an examination, aim to gain maximum marks for minimum knowledge ● ● ● ● ● ● Score marks in all questions Never leave a question blank because you are short of time It is much easier to score the first few marks in a question than the last few marks Answer the question asked Make sure you don’t leave any parts out There are no marks for unnecessary extra information You not lose marks if you make the wrong choice, so you should always answer every multiple-choice question Sometimes you may be able to reject two of the options as wrong, but then find that you are not sure which of the remaining two options is correct You should make an intelligent guess and pick one of them Short-answer questions Most of the parts of a structured question demand short answers worth 1–3 marks Typical parts of such questions involve: ● naming, stating or giving information ● writing balanced equations ● describing reactions ● explaining the meaning of key terms ● plotting graphs ● interpreting data ● performing calculations When answering these questions, you should use the space allowed for your answer and the number of marks allocated to guide you when deciding how much to write Three marks for part of a question probably means that the examiner is expecting three good points to be made If asked for a chemical test, for example, one mark might be for the reagent to be used, one for the conditions and the third for describing the observations As explained in the next section, it is very important that you pay attention to the ‘command words’ and provide the type of answer that the examiner has asked for Tip Watch your language Don’t use the wrong words ● ● Do you mean ions or atoms or molecules? Don’t use the words ‘atom’ or ‘molecule’ when discussing an ionic lattice such as sodium chloride Don’t use the word chloride (for the ion) when you mean atoms or molecules of the element chlorine (and vice versa) Bonds or forces? Molecules have covalent bonds between atoms within/inside the molecules These not break when molecular substances melt or boil Between the molecules there are (intermolecular) forces, not bonds These forces are overcome when a molecular substances melt or boils A2.2 Exam technique 807466_app02_Edexcel Chemistry_301-306.indd 305 305 30/03/2015 12:23 Longer answer questions Questions requiring longer answers carry 4–6 marks in the Edexcel examination papers Some of them ask for a description, interpretation or explanation; others require a calculation that involves several stages Here, too, you must pay careful attention to the command words In a prose answer, you will not get credit for copying phrases from the question This seems obvious but students commonly lose marks by simply repeating the question It can help to jot down key points in rough so that you can decide on the best order to cover them Write short, clear sentences Keep your answer relevant by dealing with all the points asked for in the question If you are asked to carry out an extended calculation, without any help from the structure of the question, you must set out your working step by step with enough words to show what you are doing at each step The worked examples in the main chapters of this textbook show you how to this for each of the types of calculation that feature in this course Marks are awarded for each stage of the quantitative argument, as you can see by looking at Edexcel mark schemes Examiners’ terms Every year, too many well-prepared candidates fail to score as many marks as they should because they not answer the question set by the examiners Tip Curly arrows in organic mechanisms must start at a bond or a lone pair and end forming a new bond or a lone pair on an atom Don’t forget to add the dipoles to relevant bonds too Examiners try very hard to set questions which are clear to candidates Even so, under examination conditions, it is all too easy to rush into writing an answer before checking carefully what you have been asked to by the examiner You not get marks if you fail to answer the question that the examiner has set you A useful first step is to highlight the command words in the question Words such as ‘calculate’, ‘describe’ and ‘explain’ give instructions The command words used by examiners in Edexcel chemistry papers are defined in Appendix of the specification 306 A2 Preparing for the exam 807466_app02_Edexcel Chemistry_301-306.indd 306 30/03/2015 12:23 Index Note: page numbers in bold refer to illustrations A absorption spectra 229 accuracy of measurements 138 acid–base titrations 136–8 acids 10–11 reactions of 95–6 solubilities of 97 strong and weak 137 activation energy 270–1 addition reactions 162, 188–9 addition polymerisation 163, 198 reaction mechanisms 190–2 to unsymmetrical alkenes 193–4 air pollution 180–1 alcohols 152, 153 combustion reactions 214 dehydration of 221 determining the type of 218–19 names and structures 212–13 oxidation reactions 217–20 physical properties 214 substitution reactions 204, 210, 215–16 aldehydes 153, 217 testing for 219 aliphatic hydrocarbons 171 alkali metals see Group elements alkaline earth metals see Group elements alkalis 11 reactions of 95–6 alkanes 157, 171 cracking 178 naming compounds 158–9 physical properties 62, 172 reactions of 172–5, 204 reforming 179 alkenes 152, 153 addition polymers 195–8 addition reactions 162, 188–9, 204 combustion reactions 187 double bonds 184–5 formation of 221 naming compounds 159–60 oxidation reactions 189–90 physical properties 184 reaction mechanisms 190–2 unsymmetrical molecules, addition reactions 193–4 alkyl groups 158 alkynes 153 alpha particles, Rutherford’s experiments 14 amines 153, 202 ammonia molecular shape 53 reaction with halogenoalkanes 208 reaction with hydrogen halides 114, 275 ammonium ions 47 shape 51 testing for 145 anabolic steroids 23 analysis identification of inorganic unknowns 144–6 identification of organic unknowns 233 infrared spectroscopy 229–32, 299 mass spectrometry 17–18, 22–3, 225–8, 298–9 arenes 171 arithmetic mean 290–1 aromatic hydrocarbons 171 aspirin atom economy 143, 297 addition reactions 162 atomic number 16–17 atomic orbitals 26–7, 30 atomic structure early ideas 12–13 ‘plum pudding’ model 14 Rutherford’s model 15 atoms electron structure 23–9 averages 290–1 Avogadro constant 120–1 B barium 101, 102 compounds of 104–6 reactions of 103–4 see also Group elements baryte 106 bases 11 solubilities of 97 basic oxides 104 Benedict’s solution 219 beryllium 101, 102, 103 see also Group elements beryllium chloride, shape 51, 52 best-fit line 297 bias 139, 140 biofuels 182–3, 212 boiling temperatures of alkanes 62 of ionic compounds 43 of metals 74 of noble gases 61 relationship to physical properties 76 of simple molecular structures 50 bond angles 50–2 effect of lone pairs 53–4 bond energies 48–9 bond enthalpies 255–8 bond lengths 48–9 bonding covalent 45–7 ionic 42 metallic 45, 73–4 relationship to physical properties 76 boron trifluoride, shape 51, 52 bromine 108, 109 reactions of 110–11 see also Group elements butane 157 see also alkanes C calcium 101 compounds of 104–6 reactions of 103–4 see also Group elements calculations involving chemical equations 127–9, 294–7 mathematical equations and expressions 292–3 order of operations 286–7 calorimeters 240, 242 carbocations 191 primary, secondary and tertiary 193–4 stability of 194 carbon 150–1 allotropes of 69–72 carbon dioxide bonding testing for 104–5, 145 carbon monoxide 180 carbon neutral processes 182–3 carbonates of Group metals 99 of Group compounds 105 reaction with acids 96 testing for 145 thermal stability 106–7 carboxylic acids 153, 217, 218 Index 807466_ndx_Edexcel Chemistry_307-311.indd 307 307 30/03/2015 13:35 catalysts 267, 271–2 catalytic converters 180–1 catalytic hydrogenation of alkenes 188–9 Chadwick, James 15–16 chain isomers 161 chemical kinetics 262 see also rates of reaction chlorate ions 115 chlorine 108 isotopes 20 reactions of 99, 104, 110–11, 173–5, 280 testing for 145 water treatment 115 see also Group elements chlorofluorocarbons (CFCs) 211–12 cis–trans isomerism 186–7 citric acid 10 cobalt chloride paper 274–5 collision theory 268–71 combustion of alcohols 214 of alkanes 172–3 of alkenes 187 enthalpy changes 239–41 incomplete 180 standard enthalpy change of 246 composites 70 compounds of metals with non-metals 7–8 of non-metals with non-metals 5–6 concentration effect on equilibrium 278–9 effect on the rate of a reaction 265, 269 of solutions 130 copper(ii) sulfate crystals, thermal decomposition 94 copper(ii) sulfate solution, reaction with zinc 83–4 covalent bonding 45–6 bond lengths and bond energies 48–9 dative covalent bonds 47 lone pairs of electrons 46–7 multiple bonds 46 polar bonds and polar molecules 55–9 shapes of molecules and ions 50–4 covalent structures giant lattices simple molecular structures 49–50 cracking 178 crude oil 176–7 use in polymer manufacture 196 crystals 39, 40 cyanide ions, reaction with halogenoalkanes 207–8 D d-block elements 30 d orbitals 26–7 Dalton, John 12–13 data handling 289–92 308 dative covalent bonds 47 decimal places 290 dehydration reactions, alcohols 221 delocalised electrons 73 Democritus 12 diamond 69–70 diesel engines, air pollution 180 dilutions 134 dipole–dipole interactions 63 dipoles 58–9 displacement reactions 83–4, 112 displayed formulae 156 disproportionation reactions 89, 114 dot-and-cross diagrams 41 double bonds 46, 184–5 influence on shape of molecules and ions 54 dynamic equilibrium 278 E electrical conductivity of ionic compounds 43 of metals 74 relationship to physical properties 76 and simple molecular structures 50 electrolysis 43 electrolytes 43 electron configurations 27–8 of Group metals 98 of Group elements 102 of the halogens 108 and the periodic table 30–1 electron transfer, redox reactions 82–3 electronegativity 56–7 electron-pair repulsion theory 51 electrons 5, 16 atomic orbitals 26–7 discovery of 13–14 energy levels 23–6 electrophiles 166 electrophilic addition reactions 188–90 addition to unsymmetrical alkenes 193–4 reaction mechanisms 190–2 electrostatic attraction 42, 50 elements atoms metals and non-metals 4–5 elimination reactions 162, 163, 221 halogenoalkanes 209 empirical formulae 121–3, 154 endothermic changes 239, 255 equilibrium 281 end-point in a titration 136 energy levels 23–6 enthalpy changes 237 and bonding 255–8 and the direction of change 254–5 endothermic 239 exothermic 237–8 Hess’s Law 248–54 measurement of 239–43, 244–5 standard 243, 245–8 enthalpy level diagrams 238, 239 equilibrium 276–7 dynamic 278 homogeneous and heterogeneous 283 influencing factors 278–81 qualitative predictions 284 reaction of iodine and chlorine 280 equilibrium constants 282–3 equivalence point 136 errors, sources of 139–40 in thermochemical experiments 241–2 ETBE 178 ethane 152, 157 see also alkanes ethanol 151, 152 oxidation of 220 see also alcohols ethers 153, 161 exam technique 304–6 exothermic changes 237–8, 254–5 equilibrium 281 extrapolation of a graph 297–8 E/Z isomerism 185–7 F f-block elements 30 f orbitals 26–7 Fehling’s solution 219 fingerprint regions, infrared spectroscop 232 first ionisation energies, periodic pattern 33–4 flame colours of Group elements 100–1 of Group compounds 106 fluorine 108 see also Group elements fluorite 101 formation, standard enthalpy change of 246–7 fractional distillation 176–7 free-radical substitution 174 free radicals 165 fuels, alternative 182–3 fuels from crude oil (fossil fuels) 176–7, 182 air pollution 180–1 fullerenes 71–2 functional group isomers 161 functional groups 151 G gas laws 124 gas volume calculations 128–9 gases kinetic theory 268 molar volume of 126, 129 volume calculations 295 volume measurement 128 Index 807466_ndx_Edexcel Chemistry_307-311.indd 308 30/03/2015 13:35 geckos 60 general formulae 151 giant structures 39, 40, 68 allotropes of carbon 69–72 gold, electron micrograph 16 Gore-tex® 202 graphene 72 graphite 70–1 graphs 297–9 Group elements (alkali metals) 31, 97–8 compounds of 99–100 flame colours 100–1 melting temperatures 74 reactions of 99 Group compounds, flame colours 106 Group elements (alkaline earth metals) 101–3 compounds of 104–6 reactions of 103–4 Group elements (halogens) 108–9 in oxidation states +1 and +5 114–15 reactions of 110–11, 189, 191–2 solutions of 109–10 see also halide ions groups of the periodic table 29–30, 31 gypsum 105 H half-equations 83–4, 89–91 halide ions 111–12 hydrogen halides 114 reactions with concentrated sulfuric acid 113 testing for 144 halogenoalkanes 153, 202–3 elimination reactions 163, 209 formation of 173–5 hydrolysis 164 preparation of 204, 210, 215–16 substitution reactions 163, 205–8 uses and impacts 211–12 halogens see Group elements heat conduction, by metals 74 Hess’s Law 248–54 heterogeneous catalysts 267 heterogeneous equilibrium 283 heterolytic bond breaking 165–6 homogeneous equilibrium 283 homologous series 151 homolytic bond breaking 165 hydration 68 of alkenes 189 hydrocarbons 151, 171 alkanes 157, 171–5 alkenes 184–98 fuels from crude oil 176–9 hydrochlorofluorocarbons (HCFCs) 212 hydrogen, reaction with oxygen 9–10 hydrogen bonding 63–5 hydrogen halides 114 hydrogen bonding 64 reaction with alkenes 189, 191 reaction with ammonia 275 hydrogenation of alkenes 188 hydrolysis 162, 163–4 of halogenoalkanes 205–6 investigation of reaction mechanism 167–8 hydroxides of Group metals 99 of Group elements 104–5 reaction with acids 95 reaction with halogenoalkanes 206–7, 209 I ibuprofen 143 ice, hydrogen bonding 64–5 ideal gas equation 124 indicators 136–7 inductive effect 193 infrared spectroscopy 229–32, 299 intermediates 193 and catalysts 272 intermolecular forces 39, 60–1 dipole–dipole interactions 63 hydrogen bonding 63–5 and the properties of alkanes 62 and solubility 66–7 iodine 108, 109 molecular structure 49 reactions of 110–11, 280 solutions of 109–10 see also Group elements ionic bonding 42 ionic compounds 7–8, 11 properties of 43–4 ionic equations 84, 95 ionic precipitation reactions 96 ionic radii 43–4, 45 Group elements 98 Group elements 102 ionic salts 11 solubility in water 67–8 ionisation energies 23–6 Group elements 102 periodic pattern 33–4 ions formation of 41 iron cycle of extraction and corrosion 81 reaction with steam 275 iron ions reactions with halogens 111 isoelectronic molecules and ions 51 isomerism structural 160–1 E/Z 185–7 isotopes 19 K kelvin temperature scale 124 ketones 153, 217, 218 testing for 219 L lactic acid 153 lattices 42, 299 Le Chatelier’s principle 278–81 lead(ii) nitrate, reaction with potassium iodide 96 limewater 104–5, 145 limiting reagents 142 linear molecular shape 51, 54 liquids, arrangement of particles lithium 98 see also Group elements lithium compounds 99–100 logarithms 24 London forces 60–1 lone pairs of electrons 46–7 influence on shape of molecules and ions 53 M magnesium 101, 102 compounds of 104–6 reactions of 81–2, 95, 103–4 see also Group elements malleability of metals 74 mass calculations 294–5 mass number 16–17 mass spectrometry 17–18, 225–8, 298–9 of molecules 22 in sport 23 masses, calculations from equations 127 mass-to-charge ratio 18, 226 materials mathematical operations, order of 286–7 Maxwell–Boltzmann distribution 269, 271, 298 mean bond enthalpies 256 melting temperatures of alkanes 62 of ionic compounds 43 of metals 74 periodicity 32–3 relationship to physical properties 76 of simple molecular structures 50 Mendeléev, Dmitri metal oxides and hydroxides, reaction with acids 95 metallic bonding 45, 73 metals 4–5 compound formation with non-metals 7–8 properties of 73–5 reaction with acids 95 reactions with halogens 110 Index 807466_ndx_Edexcel Chemistry_307-311.indd 309 309 30/03/2015 13:35 methane 6, 157 reaction with chlorine 173–5 shape 50, 52 see also alkanes miscible liquids 67 molar masses 119 gases 124–5 molar volumes of gases 126, 129 molecular formulae 125, 154–5 molecular ions 227 moles 119, 120–1 N naming of compounds inorganic 87–8 organic 157–60, 184, 202, 212 negative numbers 287 neutralisation, standard enthalpy change of 247–8 neutrons 5, 16 discovery of 15–16 nitrates of Group metals 100 of Group compounds 105 thermal stability 106–7 nitrogen oxides air pollution 181 preparation of N2O4 92 noble gases, boiling temperatures 61 non-aqueous solvents 67 non-metals 4–5 compound formation with metals 7–8 compound formation with non-metals 5–6 reactions with halogens 111 nucleophiles 166 nucleophilic substitution reactions 205–8 O octahedral shape 52 octane numbers 177 ordinary form 287 organic chemistry 150–1 analysis of unknowns 233 empirical, molecular and structural formulae 154–6 functional groups 152–3 isomerism 160–1 naming compounds 157–60 reaction mechanisms 164–8 reaction types 162–4 see also alcohols; alkanes; alkenes; halogenoalkanes outliers 290 oxidation number rules 85 oxidation numbers balancing redox equations 91 in ions 84–6 in molecules 86 and naming of compounds 87–8 310 oxidation reactions 81, 84 of alcohols 217–20 of alkenes 189–90 see also redox reactions oxidation states 86–7 of Group metals 98 of Group elements 103 oxides of Group elements 104 oxidising agents 88–9 oxoanions 83, 114 oxonium ions 47 oxygen, reaction with Group elements 103 ozone layer depletion 211–12 P p-block elements 29, 30 p orbitals 26–7 patterns in behaviour percentage composition 122 percentage yield 142, 296–7 percentages 291 periodic properties 32 ionisation energies 33–4 melting temperatures 32–3 periodic table 4, 314 and electron structures 29–31 periods and groups 29 petrol 177 petrol engines, air pollution 180–1 phases 267 pi (π) bonds 185 plaster of Paris 105–6 polar covalent bonds 55–6 polar molecules 58–9, 67 polarisability 61 polarising power 107 poly(chloroethene) (PVC) 198 poly(ethene) (polythene) 151, 163, 195, 198 polymers 151, 195 addition polymerisation 163, 198 sustainability and recycling 196–7 poly(propene) 198 position isomers 161 potassium 98 see also Group elements potassium dichromate solution, reaction with alcohols 218 potassium iodide, reaction with lead(ii) nitrate 96 precipitation reactions 96, 144 precision 139, 140 pressure effect on equilibrium 281 effect on the rate of a reaction 269 gas laws 124 primary standards 132 propane 157 see also alkanes proportions 291–2 protons 5, 16 Q qualitative analysis 144–6 see also analysis quantitative analysis 131 see also titration quantum shells 24–5 quartz R random errors 139 rates of reaction 262 collision theory 268–71 influencing factors 265–7 measurement of 263–4 ratios 291–2 reaction mechanisms 164–6 and catalysts 267, 271–2 elimination reactions 209 investigation of 167–8 nucleophilic substitution reactions 207–8 reaction profiles 270 reaction rates see rates of reaction reactions 9–10 recycling polymers 196–7 red copper oxide, finding the formula of 123 redox reactions balanced symbol equations 81–2 balancing equations 89–91 electron transfer 82–3 ionic half-equations 83–4 recognition of 88–9 reducing agents 88–9 reduction reactions 81, 84 see also redox reactions reflux condenser 207 reforming, alkanes 179 relative atomic mass 19–20, 119 relative formula mass 21 relative isotopic mass 19 relative molecular mass 21 reversible changes 274–5 equilibrium 276–80 revision 301–3 Rutherford, Ernest 14–15 S s-block elements 29, 30 s orbitals 26–7 salts 11 solubilities of 97 saturated compounds 171 saturated solutions 66 shapes of molecules and ions 50–2, 299–300 effect of lone pairs 53–4 effect of multiple bonds 54 shielding 25, 34 sigma (σ) bonds 184–5 significant figures 289–90 silicon dioxide 6, 69 Index 807466_ndx_Edexcel Chemistry_307-311.indd 310 30/03/2015 13:35 silver halides 112, 144 simple molecular structures 39, 49–50 skeletal formulae 156 sodium 98 see also Group elements sodium chloride arrangement of ions 42 solubility in water 67–8 sodium hydroxide 99 solids solubility 66 of acids, bases and salts 97 of Group compounds 105 of Group elements 109–10 and intermolecular forces 66–7 of ionic compounds 43, 67–8 of simple molecular structures 50 solutes 66 solutions calculations involving 295–6 concentration of 130 measurement of enthalpy changes 242–3, 244–5 quantitative dilution 134 standard 132–3 solvents 66 non-aqueous 67 specific heat capacity 240 spectator ions 84, 95 sport, detection of banned drugs 23 stalactites and stalagmites 101, 274 standard enthalpy changes 243, 245–8 standard form 287–8 standard solutions 132–3 steam, reaction with alkenes 189 stereoisomerism 185–7 structural formulae 156 structural isomerism 160–1 structure 38–9 relationship to physical properties 76 sub-shells of electrons 26 substitution reactions 162, 163, 173–5 halogenoalkanes 205–8 sulfates of Group compounds 105–6 testing for 144 surface area, effect on the rate of a reaction 266, 270 synthesis systematic errors 139–40 U T water hydrogen bonding 63, 64–5 molecular shape 53 reaction with Group metals 99 reaction with Group elements 103–4 reaction with halogenoalkanes 205–6 testing for 274–5 wavenumbers 229, 230–1 weighted mean 291 temperature effect on equilibrium 281 effect on the rate of a reaction 267, 270–1 tetrahedral molecular shape 51, 54, 300 theories thermal decomposition 94 thermal stability, carbonates and nitrates 106–7 Thomson, J.J 13–14 titration 131–2, 135–6, 141 acid–base titrations 136–8 calculations 136 evaluating results 138–40 standard solutions 132–3 trans-fats 188 transition states 270 transmittance 229 trends of Group metals 98 of Group elements 102 of the halogens 108–9 trigonal bipyramid shape 52, 300 trigonal planar shape 51, 54, 300 triple bonds 46 influence on shape of molecules and ions 54 uncertainty, sources of 139 unsaturated compounds 184 unsymmetrical alkenes, addition reactions 193–4 V van der Waals, Johannes 60 variables 297 VSEPR see electron-pair repulsion theory V-shaped (bent) molecules and ions 53, 54 W X xenon atoms X-ray diffraction 38–9, 43 Y yield 142 Z zeolites 178, 262 zinc, reaction with copper(ii) sulfate solution 83–4 Index 807466_ndx_Edexcel Chemistry_307-311.indd 311 311 30/03/2015 13:35 Free online resources Answers for the following features found in this book are available online: ● Test yourself questions ● Activities You’ll also find Practical skills sheets and Data sheets Additionally there is an Extended glossary to help you learn the key terms and formulae you’ll need in your exam You can also access an extra chapter that will help you prepare for your practical work and written examinations ● Preparing for practical assessment Scan the QR codes below for each chapter Alternatively, you can browse through all resources at: www.hoddereducation.co.uk/EdexcelAChemistry1 How to use the QR codes To use the QR codes you will need a QR code reader for your smartphone/ tablet There are many free readers available, depending on the smartphone/ tablet you are using We have supplied some suggestions below, but this is not an exhaustive list and you should only download software compatible with your device and operating system We not endorse any of the third-party products listed below and downloading them is at your own risk ● for iPhone/iPad, search the App store for Qrafter ● for Android, search the Play store for QR Droid ● for Blackberry, search Blackberry World for QR Scanner Pro ● for Windows/Symbian, search the Store for Upcode Once you have downloaded a QR code reader, simply open the reader app and use it to take a photo of the code You will then see a menu of the free resources available for that topic Atomic structure and the periodic table Redox I Bonding and structure Inorganic chemistry and the periodic table 312 Free online resources 807466_QR Codes_Edexcel Chemistry_312-313.indd 312 07/04/2015 11:46 Formulae, equations and amounts of substance Energetics I 6.1 Introduction to organic chemistry Kinetics I 6.2 Hydrocarbons: alkanes and alkenes 10 Equilibrium I 6.3 Halogenoalkanes and alcohols Preparing for practical assessment Modern analytical techniques I Free online resources 807466_QR Codes_Edexcel Chemistry_312-313.indd 313 313 07/04/2015 11:46 314 The periodic table of elements 807466_PeriodicTable_Edexcel Chemistry_314.indd 314 The periodic table of elements 0(8) (18) 4.0 1.0 He H (1) hydrogen Key (2) (13) (14) (15) (16) (17) 6.9 9.0 relative atomic mass 10.8 12.0 14.0 16.0 19.0 Li Be atomic symbol B C N O F lithium beryllium name atomic (proton) number nitrogen oxygen fluorine neon 10 39.9 24.3 27.0 28.1 31.0 32.1 35.5 Mg Al Si P S Cl (3) (4) (5) (6) 39.1 40.1 45.0 47.9 50.9 K Ca Sc Ti V potassium 19 calcium 20 scandium 21 titanium 22 vanadium 23 85.5 87.6 88.9 91.2 Rb Sr Y Zr (8) (9) (10) (11) (12) aluminium 13 silicon 14 phosphorus 15 sulfur 16 chlorine 17 argon 18 52.0 54.9 55.8 58.9 58.7 63.5 65.4 69.7 72.6 74.9 79.0 79.9 83.8 Cr Mn Fe Co Ni Cu Zn zinc 30 Ga gallium 31 Ge germanium 32 As arsenic 33 Se selenium 34 Br bromine 35 krypton 36 131.3 manganese 25 iron 26 cobalt 27 nickel 28 copper 29 92.9 95.9 [98] 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 Nb Mo Tc Ru Rh Pd Ag Cd In Sn tin 50 Sb antimony 51 Te tellurium 52 I iodine 53 xenon 54 [222] yttrium 39 zirconium 40 niobium 41 132.9 137.3 138.9 178.5 180.9 183.8 Cs Ba La* Hf Ta W [223] Fr francium 87 molybdenum technetium 42 43 ruthenium 44 rhodium 45 palladium 46 silver 47 cadmium 48 indium 49 186.2 190.2 192.2 195.1 197.0 200.6 204.4 207.2 209.0 [209] [210] Re Os Ir Pt Au Hg Tl Pb Bi Po At lanthanum 57 hafnium 72 tantalum 73 tungsten 74 rhenium 75 osmium 76 iridium 77 platinum 78 [226] [227] [261] [262] [266] [264] [277] [268] [271] [272] Ra Ac** Rf Db Sg Bh Hs Mt Ds Rg radium 88 actinium 89 *Lanthanide series **Actinide series rutherfordium 104 dubnium 105 140 Ce mercury 80 thallium 81 lead 82 bismuth 83 polonium 84 141 144 [147] 150 152 157 159 163 165 167 169 173 Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb 232 [231] 238 [237] Th Pa U Np 59 28/03/2015 12:18 protactinium 91 neodymium promethium 60 61 uranium 92 neptunium 93 samarium 62 astatine 85 meitnerium damstadtium roentgenium 109 110 111 175 Lu europium 63 gadolinium 64 terbium 65 dysprosium 66 holmium 67 erbium 68 thulium 69 ytterbium 70 lutetium 71 [242] [243] [247] [245] [251] [254] [253] [256] [254] [257] Pu Am Cm Bk Cf Es Fm Md No plutonium 94 americium 95 curium 96 berkelium 97 Xe californium 98 einsteinium 99 fermium 100 mendelevium 101 nobelium 102 Lr lawrencium 103 Rn radon 86 Elements with atomic numbers 112–116 have been reported but not fully authenticated bohrium 107 praseodymium hassium 108 gold 79 seaborgium 106 cerium 58 thorium 90 Kr chromium 24 strontium 38 barium 56 Ar (7) rubidium 37 caesium 55 Ne carbon Na magnesium 12 20.2 boron 23.0 sodium 11 helium ... Photo Library; p 18 8 Lenscap/Alamy; p 19 6 Green Stock Media/Alamy; p 19 8 papa1266 – Fotolia; p. 202 Thomas Trotscher/Getty Images; p 211 Agencja Fotograficzna Caro/Alamy; p 212 Roger Job/ Reporters/Science... Inorganic chemistry and the periodic table 94 Formulae, equations and amounts of substance 11 9 6 .1 Introduction to organic chemistry 15 0 6.2 Hydrocarbons: alkanes and alkenes 17 1 6.3 Halogenoalkanes and... of an acid is replaced by a metal ion For example, magnesium sulfate, MgSO4, is a salt of sulfuric acid, H2SO4 Salts can be regarded as having two ‘parents’ They are related to a parent acid and