An Elementary Study of Chemistry

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An Elementary Study of Chemistry, by

William McPherson and William Edwards Henderson This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org
Title: An Elementary Study of Chemistry
Author: William McPherson William Edwards Henderson
Release Date: March 18, 2007 [EBook #20848]
Language: English
Character set encoding: ISO-8859-1
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AN ELEMENTARY
STUDY OF CHEMISTRY
BY
WILLIAM McPHERSON, PH.D.
PROFESSOR OF CHEMISTRY, OHIO STATE UNIVERSITY
AND
WILLIAM EDWARDS HENDERSON, PH.D.
ASSOCIATE PROFESSOR OF CHEMISTRY, OHIO STATE UNIVERSITY
REVISED EDITION
GINN & COMPANY BOSTON * NEW YORK * CHICAGO * LONDON
COPYRIGHT, 1905, 1906, BY WILLIAM MCPHERSON AND WILLIAM E. HENDERSON
ALL RIGHTS RESERVED
The Athen?um Press GINN & COMPANY * PROPRIETORS * BOSTON * U.S.A.

Transcriber's note:
For Text: A word surrounded by a cedilla such as ~this~ signifies that the word is bolded in the text. A word surrounded by underscores like this signifies the word is italics in the text. The italic and bold markup for single italized letters (such as variables in equations) and "foreign" abbreviations are deleted for easier reading.
For numbers and equations: Parentheses have been added to clarify fractions. Underscores before bracketed numbers in equations denote a subscript. Superscripts are designated with a caret and brackets, e.g. 11.1^{3} is 11.1 to the third power.
Appendix A and B have been moved to the end of the book. Minor typos have been corrected.

PREFACE
In offering this book to teachers of elementary chemistry the authors lay no claim to any great originality. It has been their aim to prepare a text-book constructed along lines which have become recognized as best suited to an elementary treatment of the subject. At the same time they have made a consistent effort to make the text clear in outline, simple in style and language, conservatively modern in point of view, and thoroughly teachable.
The question as to what shall be included in an elementary text on chemistry is perhaps the most perplexing one which an author must answer. While an enthusiastic chemist with a broad understanding of the science is very apt to go beyond the capacity of the elementary student, the authors of this text, after an experience of many years, cannot help believing that the tendency has been rather in the other direction. In many texts no mention at all is made of fundamental laws of chemical action because their complete presentation is quite beyond the comprehension of the student, whereas in many cases it is possible to present the essential features of these laws in a way that will be of real assistance in the understanding of the science. For example, it is a difficult matter to deduce the law of mass action in any very simple way; yet the elementary student can readily comprehend that reactions are reversible, and that the point of equilibrium depends upon, rather simple conditions. The authors believe that it is worth while to present such principles in even an elementary and partial manner because they are of great assistance to the general student, and because they make a foundation upon which the student who continues his studies to more advanced courses can securely build.
The authors have no apologies to make for the extent to which they have made use of the theory of electrolytic dissociation. It is inevitable that in any rapidly developing science there will be differences of opinion in regard to the value of certain theories. There can be no question, however, that the outline of the theory of dissociation here presented is in accord with the views of the very great majority of the chemists of the present time. Moreover, its introduction to the extent to which the authors have presented it simplifies rather than increases the difficulties with which the development of the principles of the science is attended.
The oxygen standard for atomic weights has been adopted throughout the text. The International Committee, to which is assigned the duty of yearly reporting a revised list of the atomic weights of the elements, has adopted this standard for their report, and there is no longer any authority for the older hydrogen standard. The authors do not believe that the adoption of the oxygen standard introduces any real difficulties in making perfectly clear the methods by which atomic weights are calculated.
The problems appended to the various chapters have been chosen with a view not only of fixing the principles developed in the text in the mind of the student, but also of enabling him to answer such questions as arise in his laboratory work. They are, therefore, more or less practical in character. It is not necessary that