Experimental inorganic/physical chemistry: An investigative, integrated approach to practical project work

367 Pages·1999·23.11 MB·English

EXPERIMENTAL INORGANIC/PHYSICAL CHEMISTRY
An Investigative, Integrated Approach to Practical Project Work
"Talking of education, people have now a-days" (said he) "got a strange opinion that
every thing should be taught by lectures. Now, I cannot see that lectures can do so much
good as reading the books from which the lectures are taken. I know nothing that can be
best taught by lectures, except where experiments are to be shewn. You may teach
chymestry by lectures - You might teach making of shoes by lectures!"
James Boswell: Life ofSamuelJohnson, 7766(1709-1784)
"Every aspect of the world today - even politics and international relations - is affected
by chemistry"
Linus Pauling, Nobel Prize winner for Chemistry, 1954, and
Nobel Peace Prize, 1962
MOUNIR Α. MALATI
Mounir Malati obtained his BSc degree in the Department of Chemistry in
Cairo University's Faculty of Science in 1943, and then was appointed
Demonstrator in the Department of Chemistry, Alexandria University, and next
in Cairo University until 1946. He afterwards became Science Master in a
Cairo independent high school until 1953. He went to England for graduate
research in the Physical Chemistry Department of Leeds University, where he
was awarded his PhD in 1957 for research on photochemical electron transfer
reactions.
Returning to Egypt, he spent a few months as Chemistry Lecturer at the
Women's Teacher Training College, Cairo before joining the National Research
Centre in Giza to take charge of a research unit, where he was promoted to
become Research Associate Professor, supervising a number of graduates
working for higher degrees. In December 1962 he again came to the United
Kingdom, researching for a year at Imperial College, London, and then took a
job as Senior Research Officer with the Paint Research Association.
In 1965 he joined Medway College of Technology (now Mid-Kent College) to
teach inorganic, physical and radiochemistry for BSc, Grad.R.S.C, and Higher
National Certificate courses. At the same time he also supervised projects for
undergraduates and graduates, where five former students from Egypt obtained
PhD degrees under his supervision. He also supervised five Mid-Kent College
students who were awarded PhD degrees, at the same time collaborating with
four post-doctoral fellows.
He has presented research papers at international conferences in the UK, USA,
Canada and mainland Europe, some dealing with experiments presented in the
book. His present interests include photocatalysis for greenhouse gas control
and the removal of water pollution. He is also interested in photochemistry and
reactions of complex compounds and adsorption of ions by oxides of Si, Fe, Μη
and Ti. He has over 150 publications.
Experimental Inorganic/Physical
Chemistry
An Investigative, Integrated Approach to Practical Project Work
M.A. MALATI
Mid-Kent College of Higher and Further Education
Chatham
W O O D H E A D P U B L I S H I N G L I M I T E D
Oxford Cambridge New Delhi
Published by Woodhead Publishing Limited, Abington Hall, Granta Park
Great Abington, Cambridge CB21 6AH, UK
www.woodheadpublishing.com
Woodhead Publishing India Private Limited, G-2, Vardaan House, 7/28 Ansari Road,
Daryaganj, New Delhi - 110002, India
www.woodheadpublishingindia.com
First published by Horwood Publishing Company, 1999
Reprinted by Woodhead Publishing Limited, 2010
©M. A. Malati, 1999
The author has asserted his moral rights
This book contains information obtained from authentic and highly regarded sources.
Reprinted material is quoted with permission, and sources are indicated. Reasonable efforts
have been made to publish reliable data and information, but the authors and the publisher
cannot assume responsibility for the validity of all materials. Neither the authors nor the
publisher, nor anyone else associated with this publication, shall be liable for any loss,
damage or liability directly or indirectly caused or alleged to be caused by this book.
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British Library Cataloguing in Publication Data
A catalogue record for this book is available from the British Library
ISBN 978-1-898563-47-1
Printed in the United Kingdom by Lightning Source UK Ltd
Copyright acknowledgement
Figures 2.10,18.3,18.4a 18.4 and A9.3 are reproduced, with permission, from Education in Chemistry.
Figures 6.1,7.1, 8.1,14.1,18.5 and A9.2 are reproduced from Fundamentals of Inorganic Chemistry by
J. Barrett and M. A. Malati, published by Horwood Publishing, 1998.
To my wife Margaret
and my daughters
Mervat and Suzy
Preface
Practical Chemistry courses have changed considerably over the past three decades.
Practical examinations have been replaced by project work, complemented by assessed
experiments lasting for two-three practical sessions. Even at H.N.D./H.N.C. level,
assignments have replaced practical examination. In project work, not only accurate
measurements and analytical results are assessed but also the student's ability to organise
and plan the practical work and to report and discuss the results intelligently. In project
work, an integrated approach is necessary where the artificial division of Chemistry into
Inorganic, Physical or Analytical is unnecessary. The title and sub-title of the book
emphasise these aspects and reflect my experience and interests. My research for my
Ph.D. degree was in the Physical Chemistry Department and my work at the National
Research Centre was mainly on the upgrading of inorganic minerals using physico-
chemical methods. Over thirty two years I taught Inorganic, Physical and
Radiochemistry and I have developed numerous projects based on an integrated
approach with emphasis on investigation. Most of the experiments described in the book
have been tried and tested or developed in our laboratory. Many of the results have been
published. To widen the scope of the book, I have also included experiments based on
published papers or taken from the references given at the end of Chapters 2 and 18.
To correlate the practical work to the theory, Chapters 3-17 start with a theoretical
introduction to the chemistry of the group or element dealt with in the chapter. Generally
a short theoretical background precedes experimental instructions.
Most of the experiments described in the book can be carried out using readily
available inexpensive chemicals and do not require expensive specialised instruments.
Safety precautions are given in Chapter I and are taken into account throughout the
book.
The Appendices are an integral part of the book. Appendices 3-18 contain the results
of the experiments described in the respective chapters or references where the results
are found. The necessary calculations are also given in the Appendices, including
treatment of kinetic data. References to other experiments are included in the
Appendices. Most of the references are given without the Authors names or the title of
the paper to save space. However, when quoting a reference from a journal not readily
accessible to English-speaking chemists, the names of the Authors are given. Each
section of an appendix is numbered (preceded by A) to correspond to the respective
section in the main chapter.
Although it is assumed that students using the book have done a course in Chemistry,
including practicals, at A level or equivalent, Chapter 1 deals with good laboratory
practice and simple operations. The theoretical background to the various techniques is
briefly explained in Chapter 2 together with references to more detailed treatments.
I acknowledge the help and encouragement I received from the late Lord Dainton
during my study in Leeds and throughout my work in the U.K. I also acknowledge the
help and encouragement I received from the late Professor A. Riad Tourky during my
study and work in Egypt.
I am grateful to Ever Ready (Central Laboratory), the Royal Society of Chemistry and
the Society of Chemical Industry for financial assistance. Thanks are due to Dr. John
Burgess for help and advice. I thank Mrs. Pamela Elsegood for the word-processing of
the text, Mr. John-Paul Phillips for producing the figures and Mrs. Rosmary Harris for
preparing the camera-ready text.
This book would not have materialised without the enthusiasm and hard work of most
of my students, my research students (both in Chatham and in Egypt) and my post­
doctoral collaborators.
I hope this book will encourage students to appreciate the thrill of carrying out
investigative projects.
Mounir A. Malati
Mid-Kent College of Higher and Further Education
LIST O F ABBREVIATIONS
a(or act.) activation LMCT ligand to metal C T .
acac acetylacetonate LorNA Avogadro constant
(aq) aqueous Μ metal
bipy bipyridine m metre
Bq disintegrations s"' max maximum
cone. concentrated MLCT metal to ligand C T .
cm centimeter nm nanometre
c.p.m. counts minute"' NMR nuclear magnetic resonance
C T . charge transfer 0 (superscript) standard
c.p.s. counts s"' Ox oxalate
dm decimeter Oxine 8-hydroxyquinoline
DMF dimethylformamide phen 1,10-phenanthroline
DMG
(or HDMG) dimethylglyoxinato pn diaminopropane
DMSO dimethylsulphoxide PZC point of zero change
DTA differential thermal analysis PZZ point of zero zeta potential
activation energy R gas constant
EDTA ethylenediaminetetraacetic acid s second
en diaminoethane (s) solid
emf electromotive force TGA thermogravimetric analysis
ESR electron spin resonance tr transition
Et ethyl t.s. transition state
E° standard redox potential O G free energy change
F Faraday constant O H enthalpy change
(g) gas O S entropy change
g gram o v volume change
h Planck's constant s wavelength
i.r. infrared effective magnetic moment
i.s. initial state Bohr's magneton
J joule molar extinction coefficient
k kilo frequency or neutrino
k o r k, rate constant magnetic susceptibility
Κ degree Kelvin et al and others
L ligand ibid in the same place (or
journal)
LF ligand field Oh octahedral
L.F.S.E. ligand field stabilisation energy Td tetrahedral
Table of Contents
1 God Safe Laboratory Practice 1
1.1 Introduction ί
1.2 Use and Care of Glasware 1
1.3 Use of Other Labware 2
1.4 Weighing 3
1.5 Heating 3
1.6 Introduction to Safety 4
1.7 Warning Symbols 4
1.8 Risk and Safety Phrases 6
1.9 Explosions and Fires 6
1.10 Fire Extinguishers 6
1.1 Spilage Treatment 6
1.12 Waste Disposable 7
1.13 CarefulUseof Concentrated Acids and Alkalis 7
1.14 Handling Organic Solvents 7
1.15 Some Simple Tests and Operations 7
1.15.1 The Flame Test 7
1.15.2 Melting Point Determination 8
1.15.3 Handling Air-Sensitive Reagents 8
2 Techniques 9
2.1 Characterisation of Solids 9
2.1.1 X-Ray Methods 9
2.1.2 Mas Spectrometry (MS) 10
2.1.3 Magnetic Measurement 10
2.1.4 The Point of Zero Charge (PZC) and the Point of Zero Zeta
Potential (PZ) of Powders 13
2.1.5 Gas Adsorption and Surface Areas 15
2.1.6 Adsorption of Ions by Oxide Powders 15
2.2 Titrimetry Using Indicators 16
2.2.1 Acid/Base Titrimetry 17
2.2.2 Redox Titrations 18
2.2.3 Precipitation Titrations 19
2.2.4 Complexometric Titration (Mainly Using E.D.T.A.) 20
2.3 Gravimetry 21
2.3.1 Precipitation from Solution 21
2.3.2 Washing, Drying and Weighing Precipitates 2
2.3.3 Electrogravimetry 23
2.4 Spectroscopic Methods 23
2.4.1 U.V./Visible Spectrophotometry 24
2.4.2 Infrared (ir) and Raman Spectroscopy 27
2.4.3 Atomic Absorption Spectroscopy 28
2.4.4 Emision Spectroscopy 29
2.4.5 N.M.R. Spectroscopy 30
2.5 Electrochemical Methods 31
2.5.1 Potentiometry 31
2.5.2 Conductometry 34
2.5.3 Coulometry 36
2.5.4 Voltametry 37
2.5.5 Amperometry 38