An Introductory Course of Quantitative Chemical Analysis - Henry Paul Talbot

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be given to each member of a large class. To this end the directions are given in such detail that there is very little opportunity for the student to go astray; but the manual is not, the author believes, on this account less adapted for use with small classes, where the instructor, by greater personal influence, can stimulate independent thought on the part of the pupil.

      The method of presentation of the subject is that suggested by Professor A.A. Noyes' excellent manual of Qualitative Analysis. For each analysis the procedure is given in considerable detail, and this is accompanied by explanatory notes, which are believed to be sufficiently expanded to enable the student to understand fully the underlying reason for each step prescribed. The use of the book should, nevertheless, be supplemented by classroom instruction, mainly of the character of recitations, and the student should be taught to consult larger works. The general directions are intended to emphasize those matters upon which the beginner in quantitative analysis must bestow special care, and to offer helpful suggestions. The student can hardly be expected to appreciate the force of all the statements contained in these directions, or, indeed, to retain them all in the memory after a single reading; but the instructor, by frequent reference to special paragraphs, as suitable occasion presents itself, can soon render them familiar to the student.

      The analyses selected for practice are those comprised in the first course of quantitative analysis at the Massachusetts Institute of Technology, and have been chosen, after an experience of years, as affording the best preparation for more advanced work, and as satisfactory types of gravimetric and volumetric methods. From the latter point of view, they also seem to furnish the best insight into quantitative analysis for those students who can devote but a limited time to the subject, and who may never extend their study beyond the field covered by this manual. The author has had opportunity to test the efficiency of the course for use with such students, and has found the results satisfactory.

      In place of the usual custom of selecting simple salts as material for preliminary practice, it has been found advantageous to substitute, in most instances, approximately pure samples of appropriate minerals or industrial products. The difficulties are not greatly enhanced, while the student gains in practical experience.

      The analytical procedures described in the following pages have been selected chiefly with reference to their usefulness in teaching the subject, and with the purpose of affording as wide a variety of processes as is practicable within an introductory course of this character. The scope of the manual precludes any extended attempt to indicate alternative procedures, except through general references to larger works on analytical chemistry. The author is indebted to the standard works for many suggestions for which it is impracticable to make specific acknowledgment; no considerable credit is claimed by him for originality of procedure.

      For many years, as a matter of convenience, the classes for which this text was originally prepared were divided, one part beginning with gravimetric processes and the other with volumetric analyses. After a careful review of the experience thus gained the conclusion has been reached that volumetric analysis offers the better approach to the subject. Accordingly the arrangement of the present (the sixth) edition of this manual has been changed to introduce volumetric procedures first. Teachers who are familiar with earlier editions will, however, find that the order of presentation of the material under the various divisions is nearly the same as that previously followed, and those who may still prefer to begin the course of instruction with gravimetric processes will, it is believed, be able to follow that order without difficulty.

      Procedures for the determination of sulphur in insoluble sulphates, for the determination of copper in copper ores by iodometric methods, for the determination of iron by permanganate in hydrochloric acid solutions, and for the standardization of potassium permanganate solutions using sodium oxalate as a standard, and of thiosulphate solutions using copper as a standard, have been added. The determination of silica in silicates decomposable by acids, as a separate procedure, has been omitted.

      The explanatory notes have been rearranged to bring them into closer association with the procedures to which they relate. The number of problems has been considerably increased.

      The author wishes to renew his expressions of appreciation of the kindly reception accorded the earlier editions of this manual. He has received helpful suggestions from so many of his colleagues within the Institute, and friends elsewhere, that his sense of obligation must be expressed to them collectively. He is under special obligations to Professor L.F. Hamilton for assistance in the preparation of the present edition.

      HENRY P. TALBOT

      !Massachusetts Institute of Technology, September, 1921!.

      PART I. INTRODUCTION

      SUBDIVISIONS OF ANALYTICAL CHEMISTRY

      GENERAL DIRECTIONS

       Accuracy and Economy of Time; Notebooks; Reagents; Wash-bottles;

       Transfer of Liquids

      PART II. VOLUMETRIC ANALYSIS

      GENERAL DISCUSSION

       Subdivisions; The Analytical Balance; Weights; Burettes;

       Calibration of Measuring Devices

       GENERAL DIRECTIONS

       Standard and Normal Solutions

      !I. Neutralization Methods!

      ALKALIMETRY AND ACIDIMETRY

       Preparation and Standardization of Solutions; Indicators

       STANDARDIZATION OF HYDROCHLORIC ACID

       DETERMINATION OF TOTAL ALKALINE STRENGTH OF SODA ASH

       DETERMINATION OF ACID STRENGTH OF OXALIC ACID

      !II. Oxidation Processes!

      GENERAL DISCUSSION BICHROMATE PROCESS FOR THE DETERMINATION OF IRON DETERMINATION OF IRON IN LIMONITE BY THE BICHROMATE PROCESS DETERMINATION OF CHROMIUM IN CHROME IRON ORE PERMANGANATE PROCESS FOR THE DETERMINATION OF IRON DETERMINATION OF IRON IN LIMONITE BY THE PERMANGANATE PROCESS DETERMINATION OF IRON IN LIMONITE BY THE ZIMMERMANN-REINHARDT PROCESS DETERMINATION OF THE OXIDIZING POWER OF PYROLUSITE IODIMETRY DETERMINATION OF COPPER IN ORES DETERMINATION OF ANTIMONY IN STIBNITE CHLORIMETRY DETERMINATION OF AVAILABLE CHLORINE IN BLEACHING POWDER

      !III. Precipitation Methods!

      DETERMINATION OF SILVER BY THE THIOCYANATE PROCESS

      PART III. GRAVIMETRIC ANALYSIS

      GENERAL DIRECTIONS

       Precipitation; Funnels and Filters; Filtration and Washing of

       Precipitates; Desiccators; Crucibles and their Preparation

       for Use; Ignition of Precipitates

       DETERMINATION OF CHLORINE IN SODIUM CHLORIDE

       DETERMINATION OF IRON AND OF SULPHUR IN FERROUS AMMONIUM SULPHATE

       DETERMINATION OF SULPHUR IN BARIUM SULPHATE

       DETERMINATION OF PHOSPHORIC ANHYDRIDE IN APATITE

       ANALYSIS OF LIMESTONE

       Determination of Moisture; Insoluble Matter and Silica; Ferric

       Oxide and Alumina; Calcium; Magnesium; Carbon Dioxide

       ANALYSIS OF BRASS

       Electrolytic Separations; Determination of Lead, Copper, Iron

       and Zinc.

       DETERMINATION OF SILICA IN SILICATES

      PART IV. STOICHIOMETRY

      SOLUTIONS OF TYPICAL PROBLEMS PROBLEMS

      APPENDIX

      ELECTROLYTIC DISSOCIATION THEORY FOLDING OF A FILTER PAPER SAMPLE NOTEBOOK PAGES STRENGTH OF REAGENTS DENSITIES AND VOLUMES OF WATER CORRECTIONS FOR CHANGE OF TEMPERATURE OF STANDARD SOLUTIONS ATOMIC WEIGHTS LOGARITHM

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