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Numerical aspects of inorganic chemistry
JOURNAL
OF THE LESS-COMMON
Elsevier Sequoia
S.A., Lausanne
477
METALS
- Printed
in The Netherlands
BOOK REVIEWS
Numerical
Aspects of Inorganic Chemistry. By R. B. Heslop, published by Elsevier Publishing Company, Amsterdam, 1970; viii+ 189 pp., 17 illus., 23 tables. Price: Dfl. 24, ca. $6.75 (hard cover); Dfl. 13, ca. $3.75 (paperback).
This book, available in both paperback and hard covers, aims to explain some of the physical methods used in the determination of many quantities, such as bond length, lattice energy and equilibrium constant, which are of interest in inorganic chemistry. It does this quite successfully in nine chapters, each consisting of brief outlines of related topics, with numerical examples and references, a list of books for further reading, and about twenty problems, answers to which are given. The material is suitable for first and second year undergraduates, although some of the more elementary topics (balancing of redox equations, Hess law calculations) could be used in later sixth-form work. The numerical examples throughout utilize SI units, and there is a first chapter summarizing this system and also quantity calculus, which is used throughout the book. The author is to be congratulated on his rigour in applying this, although in at least one instance the dimensionless term molecular weight is used for the dimensioned quantity molar mass (it is important to distinguish these when basic SI units are used, since they differ numerically by a factor of 1000). The author is also firm in keeping quantities, of which the logarithm is taken, dimensionless; this is relatively easy at this level, where the concept of activity can be utilized, but presents some difficulty at a lower level, where, for example, one would like to use the concept of pH before that of activity is likely to be understood. There are good chapters on atomic spectra, which includes an excellent summary of electron screening and Slater’s rules, and on molecular spectra, with a useful discussion on the role of electron pairs in determining the shapes of simple molecules. However, neither electron-spin nor nuclear magnetic resonance is mentioned. The chapter on applications of thermodynamics is quite disappointing containing a number of errors which will only confuse many students in a topic already taught badly enough. In discussing the entropy change for the reaction H,O(l)--+ H,O (g), the author manages to obtain the correct answer from the wrong data by an incorrect calculation. Subsequently an incorrect temperature is substituted into an equation in two separate examples, and the useful discussion of Ellingham diagrams is marred by an unfortunate choice of example. Chromium carbide, and not chromium metal is formed by the carbothermic reduction of Cr,O,; this error is repeated in one of the problems, where it is implicitly assumed that Ti(s) and C(s) can coexist at unit activity. Standard states are used in a very hazy manner, and there is an irritating lack of consistency in the value quoted for A@ (298.15) for CO,(g): -392, -393 and - 394 kJ mol- ’ are all used. There follow fairly straightforward chapters on ionic crystals (no mention of X-ray or neutron diffraction) and equilibria in aqueous solutions. The final section on magnetic moments is rather short and contains no reference to ligand field calJ. Less-Common
Metals,
24 i1971j 477479
478
J3OOK REVIEWS
culations, which have done much to revitalize this part of inorganic chemistry. Many of the problems are of the rather sterile type with no purpose or interest outside an examination paper. There are a few of more interest, in which the student can see some application of the principle involved (carbon dating of Saxon church timbers, estimation of the instability of MgCl(s), etc.) but a larger proportion of these would have been welcome. For example, the electron probe microanalyser could have been introduced as an example of the calculation of X-ray spectra, and the hypergolic fuels used on the Apollo flights could have been used for a Hess law calculation. The layout is clear and legible, with only a few minor misprints or omissions that’are nearly inevitable in the first edition of a numerical work such as this-for example a factor of 10m3r omitted in the calculation of the ionization energy of the hydrogen atom. There is a useful appendix containing the recommended values of some physical constants and relative atomic masses of the elements. To summarize, a wide range of material in the broad hinterland between inorganic and physical chemistry is covered in this book, though with the omission of some modem (and not-so-modern) techniques. With the possible exception of one chapter it should prove most useful, both as a summary and an introduction for deeper reading for the first and second year undergraduate. It should also be of some interest to sixth-form teachers. M. H. Rand
High Temperature Oxides. Part I, Magnesia, Lime and Chrome Refractories; Part II, Oxides of Rare Earths, Titanium, Zirconium, Hafnium, Niobium and Tantalum. Edited by Allen M. Alper, Academic Press, New York and London. Part I, xvi + 358 ; price
$. 17.00; Part II, xviii+276;
price $. 16.50.
These books are the first two to be published in a series of four volumes designed to cover the fundamental properties and applications of refractory oxide phases. Each of the present volumes consists of seven individual articles written by leading scientists and technologists, and the total amount of knowledge conveyed is very large and very wide ranging. Part I is concerned chiefly with modern developments in the technology and solid-state physics and chemistry of those refractory oxides which, in their simpler forms, have been used in industry for a long time and which are of especial importance in steel making ; this field is covered in considerable depth, both in its fundamental and practical aspects. Part II is concerned with the refractory oxides of metals of Groups IIIA, IVA and VA, and deals relatively to a greater extent with the preparation and physical and chemical properties of phases containing these oxides, than with their current industrial applications-though the latter also receives adequate attention. This comparison with Part I is inevitable, as these oxides of less-common metals have a great industrial potential which has not yet been fully developed. The sub-titles of the two volumes do rather less than justice to their contents. Part I contains reviews on Pitch-bearing MgO-CaO refractories for the basic oxygen steel process; Refractories based on magnesia; Sintered chemically bonded and fused J. Less-Common
Metals,
24 (1971) 477-479
OF THE LESS-COMMON
Elsevier Sequoia
S.A., Lausanne
477
METALS
- Printed
in The Netherlands
BOOK REVIEWS
Numerical
Aspects of Inorganic Chemistry. By R. B. Heslop, published by Elsevier Publishing Company, Amsterdam, 1970; viii+ 189 pp., 17 illus., 23 tables. Price: Dfl. 24, ca. $6.75 (hard cover); Dfl. 13, ca. $3.75 (paperback).
This book, available in both paperback and hard covers, aims to explain some of the physical methods used in the determination of many quantities, such as bond length, lattice energy and equilibrium constant, which are of interest in inorganic chemistry. It does this quite successfully in nine chapters, each consisting of brief outlines of related topics, with numerical examples and references, a list of books for further reading, and about twenty problems, answers to which are given. The material is suitable for first and second year undergraduates, although some of the more elementary topics (balancing of redox equations, Hess law calculations) could be used in later sixth-form work. The numerical examples throughout utilize SI units, and there is a first chapter summarizing this system and also quantity calculus, which is used throughout the book. The author is to be congratulated on his rigour in applying this, although in at least one instance the dimensionless term molecular weight is used for the dimensioned quantity molar mass (it is important to distinguish these when basic SI units are used, since they differ numerically by a factor of 1000). The author is also firm in keeping quantities, of which the logarithm is taken, dimensionless; this is relatively easy at this level, where the concept of activity can be utilized, but presents some difficulty at a lower level, where, for example, one would like to use the concept of pH before that of activity is likely to be understood. There are good chapters on atomic spectra, which includes an excellent summary of electron screening and Slater’s rules, and on molecular spectra, with a useful discussion on the role of electron pairs in determining the shapes of simple molecules. However, neither electron-spin nor nuclear magnetic resonance is mentioned. The chapter on applications of thermodynamics is quite disappointing containing a number of errors which will only confuse many students in a topic already taught badly enough. In discussing the entropy change for the reaction H,O(l)--+ H,O (g), the author manages to obtain the correct answer from the wrong data by an incorrect calculation. Subsequently an incorrect temperature is substituted into an equation in two separate examples, and the useful discussion of Ellingham diagrams is marred by an unfortunate choice of example. Chromium carbide, and not chromium metal is formed by the carbothermic reduction of Cr,O,; this error is repeated in one of the problems, where it is implicitly assumed that Ti(s) and C(s) can coexist at unit activity. Standard states are used in a very hazy manner, and there is an irritating lack of consistency in the value quoted for A@ (298.15) for CO,(g): -392, -393 and - 394 kJ mol- ’ are all used. There follow fairly straightforward chapters on ionic crystals (no mention of X-ray or neutron diffraction) and equilibria in aqueous solutions. The final section on magnetic moments is rather short and contains no reference to ligand field calJ. Less-Common
Metals,
24 i1971j 477479
478
J3OOK REVIEWS
culations, which have done much to revitalize this part of inorganic chemistry. Many of the problems are of the rather sterile type with no purpose or interest outside an examination paper. There are a few of more interest, in which the student can see some application of the principle involved (carbon dating of Saxon church timbers, estimation of the instability of MgCl(s), etc.) but a larger proportion of these would have been welcome. For example, the electron probe microanalyser could have been introduced as an example of the calculation of X-ray spectra, and the hypergolic fuels used on the Apollo flights could have been used for a Hess law calculation. The layout is clear and legible, with only a few minor misprints or omissions that’are nearly inevitable in the first edition of a numerical work such as this-for example a factor of 10m3r omitted in the calculation of the ionization energy of the hydrogen atom. There is a useful appendix containing the recommended values of some physical constants and relative atomic masses of the elements. To summarize, a wide range of material in the broad hinterland between inorganic and physical chemistry is covered in this book, though with the omission of some modem (and not-so-modern) techniques. With the possible exception of one chapter it should prove most useful, both as a summary and an introduction for deeper reading for the first and second year undergraduate. It should also be of some interest to sixth-form teachers. M. H. Rand
High Temperature Oxides. Part I, Magnesia, Lime and Chrome Refractories; Part II, Oxides of Rare Earths, Titanium, Zirconium, Hafnium, Niobium and Tantalum. Edited by Allen M. Alper, Academic Press, New York and London. Part I, xvi + 358 ; price
$. 17.00; Part II, xviii+276;
price $. 16.50.
These books are the first two to be published in a series of four volumes designed to cover the fundamental properties and applications of refractory oxide phases. Each of the present volumes consists of seven individual articles written by leading scientists and technologists, and the total amount of knowledge conveyed is very large and very wide ranging. Part I is concerned chiefly with modern developments in the technology and solid-state physics and chemistry of those refractory oxides which, in their simpler forms, have been used in industry for a long time and which are of especial importance in steel making ; this field is covered in considerable depth, both in its fundamental and practical aspects. Part II is concerned with the refractory oxides of metals of Groups IIIA, IVA and VA, and deals relatively to a greater extent with the preparation and physical and chemical properties of phases containing these oxides, than with their current industrial applications-though the latter also receives adequate attention. This comparison with Part I is inevitable, as these oxides of less-common metals have a great industrial potential which has not yet been fully developed. The sub-titles of the two volumes do rather less than justice to their contents. Part I contains reviews on Pitch-bearing MgO-CaO refractories for the basic oxygen steel process; Refractories based on magnesia; Sintered chemically bonded and fused J. Less-Common
Metals,
24 (1971) 477-479