Advanced Structural Inorganic Chemistry


INTERNATIONAL UNION OF CRYSTALLOGRAPHY
TEXTS ON CRYSTALLOGRAPHY
IUCr BOOK SERIES COMMITTEE
E. N. Baker, New Zealand
J. Bernstein, Israel
G. R. Desiraju, India
A. M. Glazer, UK
J. R. Helliwell, UK
P. Paufler, Germany
H. Schenk (Chairman), The Netherlands
IUCr Monographs on Crystallography
1 Accurate molecular structures
A. Domenicano and I. Hargittai, editors
2 P. P. Ewald and his dynamical theory of X-ray diffraction
D.W. J. Cruickshank, H. J. Juretschke, and J. Kato, editors
3 Electron diffraction techniques, Volume 1
J. M. Cowley, editor
4 Electron diffraction techniques Volume 2
J. M. Cowley, editor
5 The Rietveld method
R. A. Young, editor
6 Introduction to crystallographic statistics
U. Shmueli and G. H.Weiss
7 Crystallographic instrumentation
L. A. Aslanov, G. V. Fetisov, and G. A. K. Howard
8 Direct phasing in crystallography
C. Giacovazzo
9 The weak hydrogen bond
G. R. Desiraju and T. Steiner
10 Defect and microstructure analysis by diffraction
R. L. Snyder, J. Fiala, and H. J. Bunge
11 Dynamical theory of X-ray diffraction
A. Authier
12 The chemical bond in inorganic chemistry
I. D. Brown
13 Structure determination from powder diffraction data
W. I. F David, K. Shankland, L. B. McCusker,
and Ch. Baerlocher, editors
14 Polymorphism in molecular crystals
J. Bernstein
15 Crystallography of modular materials
G. Ferraris, E. Makovicky, and S. Merlino
16 Diffuse x-ray scattering and models of disorder
T. R.Welberry
17 Crystallography of the polymethylene chain: an inquiry into the
structure of waxes
D. L. Dorset
18 Crystalline molecular complexes and compounds: structure and
principles
F. H. Herbstein
19 Molecular aggregation: structure analysis and molecular simulation
of crystals and liquids
A. Gavezzotti
20 Aperiodic crystals: from modulated phases to quasicrystals
T. Janssen, G. Chapuis, and M. de Boissieu
21 Incommensurate crystallography
S. van Smaalen
IUCr Texts on Crystallography
1 The solid state
A. Guinier and R. Julien
4 X-ray charge densities and chemical bonding
P. Coppens
5 The basics of crystallography and diffraction, second edition
C. Hammond
6 Crystal structure analysis: principles and practice
W. Clegg, editor
7 Fundamental of crystallography, second edition
C. Giacovazza, editor
8 Crystal structure refinement: a crystallographer’s guide to SHELXL
P. Müller, editor
9 Theories and techniques of crystal structure determination
U. Shmueli
10 Advanced structural inorganic chemistry
W.-K. Li, G.-D. Zhou, and T.C.W. Mak

Advanced Structural
Inorganic Chemistry
WAI-KEE LI
The Chinese University of Hong Kong
GONG-DU ZHOU
Peking University
THOMAS CHUNGWAI MAK
The Chinese University of Hong Kong

3
Great Clarendon Street, Oxford OX2 6DP
Oxford University Press is a department of the University of Oxford.
It furthers the University’s objective of excellence in research, scholarship,
and education by publishing worldwide in
Oxford NewYork
Auckland CapeTown Dar es Salaam Hong Kong Karachi
Kuala Lumpur Madrid Melbourne Mexico City Nairobi
New Delhi Shanghai Taipei Toronto
With offices in
Argentina Austria Brazil Chile Czech Republic France Greece
Guatemala Hungary Italy Japan Poland Portugal Singapore
South Korea Switzerland Thailand Turkey Ukraine Vietnam
Oxford is a registered trade mark of Oxford University Press
in the UK and in certain other countries
Published in the United States
by Oxford University Press Inc., New York
©Wai-Kee Li, Gong-Du Zhou and Thomas C.W. Mak
The moral rights of the authors have been asserted
Database right Oxford University Press (maker)
First published 2008
All rights reserved. No part of this publication may be reproduced,
stored in a retrieval system, or transmitted, in any form or by any means,
without the prior permission in writing of Oxford University Press,
or as expressly permitted by law, or under terms agreed with the appropriate
reprographics rights organization. Enquiries concerning reproduction
outside the scope of the above should be sent to the Rights Department,
Oxford University Press, at the address above
You must not circulate this book in any other binding or cover
and you must impose this same condition on any acquirer
British Library Cataloguing in Publication Data
Data available
Library of Congress Cataloging in Publication Data
Data available
Typeset by Newgen Imaging Systems (P) Ltd., Chennai, India
Printed in Great Britain
on acid-free paper by
Biddles Ltd., King’s Lynn, Norfolk
ISBN 978–0–19–921694–9
ISBN 978–0–19–921695–6
1 3 5 7 9 10 8 6 4 2
Download Sekarang
Share:

Langkah- langkah Metode Ilmiah

Guru atau pengajar adalah pengambil keputusan dalam kelas. Keputusan yang perlu diambil guru adalah merencanakan pengalaman belajar, menentukan metode mengajar, menentukan sistem penilaian, dan banyak lagi yang dihadapi guru setiap hari yang perlu keputusan.

Guru adalah ahli bagi siswa dikelasnya. Ahli yang mempunyai pengetahuan dan keterampilan dalam mengambil berbagai keputusan yang valid dan cara melakukannya. Dalam mengambil keputusan guru dapat melakukannya berdasarkan pengalaman, otoritas dan tradisi, tetapi yang memberi sumbangan terbesar adalah hasil penelitian ilmiah, karena telah diuji validitasnya menggunakan metode ilmiah.

Keputusan yan diambil dari serangkaian kegiatan penelitian dengan menerapkan metode ilmiah telah memberi perubahan besar dalam pendidikan. Para guru dapat memanfaatkan berbagai sumber hasil penelitian ilmiah pendidikan untuk mendapatkan informasi dan saran dalam mengambil keputusan.

Sumber pengetahuan dalam mengambil keputusan dapat dikelompokkan menjadi:

1. Pengalaman
Pengalaman adalah sumber pengetahuan yang telah banyak diketahui dan digunakan oleh orang pada umumnya. Bahkan semua manusia belajar dari pengalaman. Seorang anak kecil yang karena tanpa pengetahuan memegang api, berdasarkan pengalaman tersebut ia memperoleh pengetahuan bahwa api itu panas.
Seorang guru setiap hari memperoleh banyak pengetahuan dari pengalaman mengajar di kelasnya setiap hari. Bahkan mungkin telah menemukan banyak metode mengajar yang ia temukan tanpa ia sadari, bahwa dirinya adalah seorang penemu atau seorang ahli di kelasnya.

2. Otoritas atau wewenang
Otoritas atau wewenang adalah sumber pengetahuan yang tidak dapat diperoleh dari pengalaman pribadi. Misalnya seorang siswa akan membuka kamus untuk mencari arti kata yang asing baginya. Seorang pasien akan bertanya kepada dokter tentang penyakitnya. Jenis pengetahuan ini diperoleh dari orang lain yang memiliki pengalaman atau orang yang dianggap ahli pada bidangnya. Guru dapat memperoleh dan memanfaatkan pengetahuan ini dari para ahli pendidikan.

3. Cara berpikir deduktif
Cara berpikir deduktif adalah cara berpikir yang dirumuskan sebagai suatu proses berpikir yang bertolak dari pernyataan yang bersifat umum ke pernyataan yang bersifat khusus dengan memakai kaidah logika tertentu. Logika yang digunakan adalah suatu sistem penyusunan fakta yang telah diketahui untuk membuat kesimpulan. Cara ini dilakukan menggunakan serangkaian pernyataan yang disebut silogisme yang terdiri dari:
1) pokok pikiran utama (premis mayor)
2) pokok pikiran kedua (premis minor)
3) kesimpulan
Contoh silogisme:
1) Semua larutan yang memiliki pH < 7 adalah larutan asam.
2) Larutan HCl encer memiliki pH < 7.
3) Larutan HCl encer adalah larutan asam.
Jika premisnya benar, maka kesimpulannya pasti benar.

4) Cara berpikir induktif
Kesimpulan yang dihasilkan dari cara berpikir deduktif hanya benar jika premisnya benar. Namun, bagaimana mengetahui bahwa premis itu pasti benar dan valid.
Misal contoh:
1) Semua siswa yang diajar dengan metode A mendapat nilai > 80.
2) Kelas X diajar dengan metode A.
3) Semua siswa kelas X mendapat nilai > 80.
Bisa saja ini benar untuk kesimpulan kelas X, namun belum tentu untuk kelas Y dan Kelas Z. Jadi kesimpulan ini hanya benar pada kondisi tertentu, dan belum dapat digeneralkan.
Francis Bacon adalah orang yang mengusulkan ide bahwa untuk mencari kebenaran atau pengetahuan seseorang harus mengamati alam secara langsung, mengumpulkan fakta-fakta, dan merumuskan generalisasi dari hasil pengamatan tersebut.
Contoh cara berpikir induktif:
Semua kelas yang diajar dengan metode A mendapat nilai rata-rata > 80.
Oleh karena itu, semua siswa yang diajar dengan metode A mendapat nilai > 80.
Perhatikan bahwa cara berpikir deduktif mengamati contoh-contoh atau seluruh kelas, baru dibuat generalisasi untuk seluruh siswa.

5) Metode Ilmiah atau Pendekatan Saintifik atau Pendekatan Ilmiah
Charles Darwin dianggap sebagai orang pertama yang menerapkan metode ilmiah dalam mencari pengetahuan dan kebenarannya. Darwin melakukan pengamatan makhluk hidup dan berharap dapat membuat generalisasi tentang evolusi makhluk hidup. Penggabungan cara berpikir induktif-deduktif telah menjadi metode baru yang disebut metode ilmiah. Pada metode ilmiah hasil pengamatan pada fakta-fakta dirumuskan menjadi kesimpulan sementara atau disebut hipotesis. Kesimpulan sementara atau hipotesis ini harus diuji kebenarannya dan validitasnya sebelum digeneralisasi.
Metode ilmiah adalah cara berpikir yang dideskripsikan sebagai proses yang dalam hal ini peneliti secara induktif bertolak dari pengamatannya menuju hipotesis. Oleh karena itu, pada metode ilmiah umumnya peneliti memikirkan apa yang akan terjadi jika hipotesis benar, kemudian melakukan pengamatan yang lebih sistematis untuk menerima atau menolak hipotesis. Metode ilmiah adalah suatu proses penelitian yang sistematis yang terdiri atas variabel-variabel yang saling bergantung atau interdependen variabel. Metode ilmiah pada umumnya meliputi langkah-langkah metode ilmiah berikut:

Langkah 1 Metode ilmiah: Perumusan Masalah
Penelitian ilmiah dimulai dengan menemukan masalah yang memerlukan pemecahan atau penyelesaian atau solusi atas masalah. Masalah harus dapat dirumuskan sehingga dapat dijawab dengan pengamatan dan pengukuran. Masalah yang menyangkut pilihan dengan angka kuantitatif tidak dapat dijawab dengan pengamatan fakta saja. Misal, apakah siswa yang diajar dengan metode A akan memperoleh nilai lebih tinggi daripada siswa yang diajar dengan metode B?. Masalah ini dapat dijawab dengan menerapkan metode ilmiah dalam serangkaian penelitian.

Langkah 2 Metode ilmiah: Membuat hipotesis
Hipotesis adalah penjelasan atau jawaban sementara atas rumusan masalah. Peneliti harus memiliki cukup informasi dengan membaca berbagai sumber untuk merumuskan masalah atau membuat hipotesis.

Langkah 3 Metode ilmiah: Pengumpulan Data
Tahap pengumpulan data dilakukan dengan cara pengamatan dan pengukuran untuk memperoleh data yang ada hubungannya dengan masalah yang diteliti atau untuk menjawab rumusan masalah yang diteliti melalui pengamatan, tes dan eksperimen.

Langkah 4 Metode ilmiah: Analisis Data
Jika data yang diperlukan untuk menjawab masalah sudah terkumpul, maka hasil pengamatan dan pengukuran dianalisis dengan teknik analisis data yang tepat untuk memberikan bukti-bukti empiris yang mendukung hipotesis ditolak atau diterima.

Langkah 5 Metode ilmiah: Penarikan kesimpulan
Berdasarkan hasil analisis data dapat ditarik kesimpulan apakah hipotesis diterima atau ditolak. Kesimpulan yang diambil didukung dengan bukti-bukti empiris.

Semoga bermanfaat bagi yang mau menerapkan langkah-langkah metode ilmiah di atas.
Share:

Structure Inorganic Chemistry


Structural
Inorganic
Chemistry

A.F. WELLS
CLARENDON

4th Edition

CLARENDON PRESS - OXFORD
Oxford University Press
Ely House, London W1
1975

Preface
This book has been almosl entirely rewritten, but its purpose and general organization remain the same las those of previous editions. The Introduction to the first (1945) edition included dhe following paragraph: 'The reasons for writing this book were, firstly, the conviqtion that the structural side of inorganic chemistry cannot be put on a sound basls until the knowledge gained from the study of the solid state has been incorporated into chemistry as an integral part of that subject, and secondly, the equally strolng conviction that it is unsatisfactory merely to add information about the structures of solids to the descriptions of the elements and compounds as usually presented in a systematic treatment of inorganic chemistry.' Now, after a period of thirty years during which considerable advances have been made in solid state chemistry, it is still true to say that the structures and properties of solids receive very little atte~ntion in most treatments of inorganic chemistry, and this in spite of the fact that most elements and most inorganic compounds are solids at ordinary temperaturw. This state of affairs would seem to be sufficient justification for the appearance of yet another edition of this book. Since the results of structurkl studies of crystals are described in crystallographic language the first requirement is that these results be made available in a form intelligible to chemists. It was this challenge that first attracted the author, and it is hoped that this book will continue to provide teachers of chemistry with facts and ideas which can be incorporated into their teaching. However, while any addition of structural information to the donventional teaching of inorganic chemistry is to be welcomed the real need is a radical change of outlook and the recognition that not only is the structure of a substance in all states of aggregation an essential part of its full description (or characterization) but also that the structures and properties of solids form an integral part, pedhaps the major part, of the subject. The general plan of the boqk is as follows. Part I deals with a number of general topics and is intended as an introduction to the more detailed Part 11, which forms the larger part of the book. In Part I1 the structural chemistry of the elements is described systematically, and the arrangement of material is based on the groups of the Periodic Table. The advanlces made during the past decade have necessitated considerable changes in these latter chapters, but the major structural changes have been made in the content of Part I. Since a concise treatment of certain geometrical and topological topics is not readily available elsewhere mode space has been devoted to these than in previous editions at the expense of subjects such as the experimental methods of structural chemistry, which at best can receive only a sketchy treatment in a volume such as this. Many students find difficulty in appreciating the three-dimensional geometry of crystal structures from two-dimensional illustrations (even stereoscopic photographs). In order to acquire some facility in visualising the three-dimensional arrangements of atoms in crystals some acquaintance is necessary with symmetry, repeating patterns, sphere-packings, and related topics. Some of this material could be, and sometimes is, introduced into teaching at an early age. However, there is a tendency in some quarters to regard solid geometry as old-fashioned and to replace it in school curricula by more fashionable aspects of mathematics. This adds to the difficulties of those teachers of chemistry who wish to modernize their teaching by including information about the structures of solids. Unless the student has an adequate grounding in the topics noted above little is gained by adding diagrams of unit cells of crystal structures to conventional chemistry texts. The educational value of building models representing the arrangements of atoms in crystals cannot be over-emphasized; and by this we mean that the student actually assembles the model and does not simply look at a ready-made model, however much more elegant the latter may be. Some very tentative suggestions for model building have been offered in the author's Models in Structural Inorganic Chemistry, to which the abbreviation MSIC in the present volume refers. References. The present volume has never been intended as a reference work, though it may serve as a useful starting-point when information is required on a particular topic. As an essential part of the educational process the advanced student should be encouraged to adopt a critical attitude towards the written word (including the present text); he must learn where to find the original literature and to begin to form his own judgment of the validity of conclusions drawn from experimental data. It is becoming increasingly difficult to locate the original source of a particular item of information, and for this reason numerous references to the scientific literature are included in the systematic part of this book. These generally refer to the latest work, in which references to earlier work are usually included. To save space (and expense) the names of scientific journals have been abbreviated to the forms listed on pp. mi-xxiii. Indexes. There are two indexes. The arrangement of entries in the formula index is not entirely systematic for there is no wholly satisfactory way of indexing inorganic compounds which retains chemically acceptable groupings of atoms. The formulae have been arranged so as to emphasize the feature most likely to be of interest to the chemist. The subject index is largely restricted to names of minerals and organic compounds and to topics which are not readily located in the list of contents. Acknowledgments. During the writing of this book, which of necessity owes much to the work and ideas of other workers in this and related fields, I have had the benefit of helpful discussions with a number of colleagues, of whom I would particularly mention Dr. B. C. Chamberland. I wish to thank Dr. B. G. Bagley and the editor of Nature (London) for permission to use Fig. 4.3, Dr. H. T. Evans and John Wiley and Sons for Figs Sc, 7, 10, 11, and 12b in Chapter 11, and Drs. G. T. Kokotailo and W. M. Meier for Fig. 23.27. It gives me great pleasure to acknowledge the debt that I owe to my wife for her support and encouragement over a period of many years.
A. F. Wells
Department of Chemhtry,
University of Connecticut,
Storrs, Connecticut,
U.S.A.
1974
Download Sekarang
Share:

Kimia dasar McMurry Fay


Life has changed more in the past two centuries than in all the previously recorded span of human
history. The earth’s population has increased more than fivefold since 1800, and life expectancy has nearly doubled because of our ability to synthesize medicines, control diseases, and increase crop yields. Methods of transportation have changed from horses and buggies to automobiles and airplanes because of our ability to harness the energy in petroleum. Many goods are now made of polymers and ceramics instead of wood and metal because of our ability to manufacture materials with properties unlike any found in nature. In one way or another, all these changes involve chemistry, the study of the composition, properties, and transformations of matter. Chemistry is deeply involved in both the changes that take place in nature and the profound social changes of the past two centuries. In addition, chemistry is central to the current revolution in molecular biology that is now exploring the details of how life is genetically controlled. No educated person today can understand the modern world without a basic knowledge of chemistry.
Download Sekarang
Share:

Post Populer

BERLANGGANAN

ANGGOTA

Post Terbaru