Principles of inorganic chemistry

Front matter

KING’S COLLEGE HOSPIT.^^

BOOK

•••••...

Preface

Inorganic Chemistry within the last few years has undergone remarkable developments. This is due chiefly to generalizations which have been reached through physical chemistry. We can see most clearly what these developments are by comparing the inorganic chemistry of twenty years ago with that of to-day. Until recently the more important generalizations upon which the science of inorganic chemistry rested were : The conservation of mass and energy ; the laws of definite and multiple pn>i»ortions and combining weights ; the law of Avogadro, and the periodic system. Inorganic chemistry was built upon these generalizations, and consisted largely in a description of the compounds formed as the result of the interaction of matter in terms of these laws. Relations between the composition and properties of comjtounds of different elements were pointed out, which were more or less deep-seated and far-reaching.

Within the last fifteen years several newly discovered generalizations have been added to those longer known, and some of these have been shown to be fundamental to the whole science of chemistry. The more important of these generalizations are : The theory of electrolytic dissociation ; the law of mass action ; the phase rule, and Faraday’s law as the basis of chemical valence.

That these generalizations are of the very greatest importance for inorganic chemistry is obvious to any one who is familiar with the facts of physical chemistry and of inorganic chemistry. Take the theory of electrolytic dissociation, discovered by Van’t Hoff and Arrhenius. We know to-day that nearly all inorganic reactions are reactions between ions; molecules and atoms as such having nothing to do with the reactions. They simply serve to furnish the ions, which are chemically the active agents. This obviously necessitates a fundamental change in out conceptions of chemical phenomena. It is not the uncharged atoms which react chemically, but these become chemically active only when they carry an electrical charge. The chemistry of atoms and molecules is thus largely replaced by the chemistry of ions.

Similarly, the law of mass action of Guldberg and Waage has produced a fundamental change in our method of regarding cherai-

v

VI

PREFACE cal reactions. It has not only shown that mass is an important factor in determining the magnitude of any given reaction, but in many cases can actually determine the direction of the reaction. In this law we have not simply a qualitative statement of the effect of mass, but a quantitative relation mathematically formulated.

The phase rule of Willard Gibbs has also played its part in the recent developments in inorganic chemistry. It has laid special stress upon the conditions of equilibrium between the different phases of the same and different substances, and has predicted the existence of unknown substances, many of which have recently been found. The phase rule is a beautiful, short-hand expression of great masses of facts, and it gives us a comprehensive grasp of these facts which without it would be impossible.

The application of Faraday’s law as the basis of chemical valence is not a new conception, but the importance of this application has only recently become apparent. The importance of ions, which are charged atoms or groups of atoms, and the study of electrochemical phenomena in general have made prominent the fact that the law of Faraday is a fundamental law of chemistry as well as of physical chemistry. If we do not recognize this relation, the term “ chemical valence” is without exact significance and meaning; when based upon the law of Faraday — a law to which thus far no exception is known — valence has an exact physical basis, and this is an important step for the development of chemistry.

The object of the present work is not to abandon the older generalizations, nor even the older methods of treating chemical phenomena in so far as they cannot be improved. On the contrary, the attempt has been made to retain those generalizations at their full value, and special stress is laid upon the periodic system, which has apparently fallen in certain directions somewhat into disrepute. This generalization reached by Lothar Meyer and Mendeleeff, which has been the philosophy of inorganic chemistry for so many years, and in terms of which so much has been discovered, is still of very great value. That it has serious defects no one can doubt; that these are far exceeded by its merits is strongly impressed upon the writer.

The aim of this book is to add to the older generalizations those recently discovered, and to apply them to the phenomena of inoiganic chemistry in such a way that they may form an integial pait of the subject, and, at the same time, be intelligible to the student. Why should we continue to teach the chemistry of atoms to students on the ground of its being a little simpler, perhaps, than the cliem-

PREFACE

VU istry of ions, or on any other ground, if we know that it is not in accordance with the recently discovered facts ? Or why should we continue to teach purely descriptive chemistry when the science of chemistry has outgrown this stage, and many of the most important relations have been accurately formulated in terms of the simpler mathematics ?

These are questions which need only to be asked in order that their answer may be made apparent. If a student can grasp the conception of an atom and cannot add to this the idea of the atom carrying an electrical charge, his hope of ever learning anything of chemical phenomena in general is not bright.

The second point, the introduction of elementary mathematics into chemistry, may seem to be more serious. The earlier text-books on inorganic chemistry have been characterized by the absence of anything resembling a mathematical symbol, and chemistry has come to lie known as a non-mathematical science. It is, however, obvious to any one who hits traced the development of science that this condition of things cannot last. Physics has passed through the stages through which chemistry is now passing Faraday, the leading physicist of his day, was not a mathematician, but how different at present, when to lie a physicist one must first be a fairly good mathematician. Indeed, it has been well said, that the state of development of any branch of natural science can be measured by the extent to which mathematical methods have been applied to it. That chemistry will l**oome more and more mathematical is just as certain as that it will develop.

There seems to lie no good reason why we should refrain for a moment from introducing simple, algebraic symbols into a comparatively elementary text-book in inorganic chemistry, where these l*est serve to bring out tile relations lietween phenomena. They are introduced without question on almost every page of elementary works on physics, and have come to lie taken as a matter of course. The same class of students, and frequently the same students, use these works and corresponding texts on chemistry. Why should chemists be hampered by being compelled to descril)e phenomena at length when these could lie formulated in a single line? The time has come when they need not be, and the earlier elementary mathematics is introduced into text-books on chemistry, the better for chemistry and for the chemist.

The writer has refrained from introducing unproved theories and disputed questions as far as j>ossible, since the student for whom this work is meant is scarcely at a stage to properly appreciate and via

PREFACE evaluate scientific discussion. The attempt has, however, been made to avoid dogmatism, since this is harmful even in an elementary work.

The physical properties of substances are described at much greater length than in the older works on inorganic chemistry. These usually follow the description of the chemical properties of the substance, and can, at the discretion of the teacher, be omitted in part or wholly if the student is not sufficiently advanced to properly appreciate their significance.

The methods of determining the molecular weights of dissolved substances are described briefly, since these problems, especially as connected with non-aqueous solvents, have become of fundamental importance in inorganic chemistry. The methods of measuring electrolytic dissociation are also discussed, and the conductivities and dissociation of a few of the best known acids and bases are given, since these furnish us with the best means of determining the relative strengths of these substances.

All experiments have been omitted from this work except in so far as they demonstrate important principles. This has been done to avoid breaking the continuity of the text ; and since this work is meant primarily for students who are engaged in qualitative and quantitative analysis, it seems far better to leave instruction in the laboratory to works devoted especially to that purpose and to the teacher.

Should the present work contribute even a little towards the introduction of physical and physical chemical conceptions into chemistry, the writer will feel amply repaid for all his labor, since it is through these conceptions and apparently through these alone that we can hope to place chemistry among the exact sciences.

HARRY C. JONES.

PAG* 1

The Study of Nature. Relations between Chemistry and Physics. Elements and Compounds. The Number of Elements and Compounds.

The Chemical Elements. Chemical Combination.

CHAPTER II Generalizatioss 7

The Science of Chemistry. Generalization. The Law of the Conservation of Mass. The Law of Constant IToportion. The Law of Multiple Proportions. The Law of Combining Weights. The Atomic Theory. The Correlation and Conservation of Energy. Importance of the Conservation of Energy for the Science of Chemistry.

Chapter III Oxtger 16

Occurrence In Nature. Preparation of Oxygen. Hydrogen Dioxide. Substances burn readily in Oxygen. Explanation of the Above Results. Combustion. The Phlogiston Theory of Combustion. The ROle of Oxygen in Combustion. Increase in Weight in Combustion. Oxygen used up in Combustion. Rapid and Slow Oxidation. Measurement of the Heat of Combustion. Heat of Formation and of Decomposition. Names of the Compounds formed with Oxygen. Certain Physical Pnqiertles of the Element Oxygen. The Pressure of Oxygen varies with the Conditions. The 1 jiw of Boyle for Gases.

The Law of Gay-Luaaac for Gases. The Determination of the Absolute Zero of Temperature. The Combined Expression of the Laws of Bovle and Gay-Lussac. The Liquefaction of Oxygen. Properties of Liquid Oxygen. Power of Oxygen to enter into Chemical Combination.

Ozowe 29

Allotmpie Modification of Oxygen. Preparation of Ozone. Properties of Ozone. Transformation of Ozone into Oxygen. The Difference between Oxygen and Ozone.

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X

CONTEXTS

Chapter IV Pagk

Occurrence. Preparation of the Element Hydrogen. Combination of Hydrogen with Oxygen. Mixture of Hydrogen and Oxygen affected by the Presence of Certain Substances. Catalytic Reactions and Catalyzers. Relations by Volume in which Hydrogen and Oxygen combine. Heat Energy produced when Oxygen and Hydrogen combine. The Oxyhydrogen Blowpipe. Dry Hydrogen will not combine with Dry Oxygen. The Reducing Power of Hydrogen. Compounds of Hydrogen with Other Metals. Hydrogen Present in All Acids. Nascent Hydrogen. Certain Physical Properties of the Element Hydrogen. The Liquefaction of Hydrogen. Can the Absolute Zero be realized Experimentally ? Properties of Liquid Hydrogen. The Hydrogen Spectrum. Electrolysis of Hydrogen.

Chapter V

Occurrence of Water. Water as it occurs in Nature is Impure. Mineral Waters. Purification of Water. Filtration. Water not an Element, but a Coihpound. Composition of Water. Chemical Behavior of Water. Water a Stable Compound. Physical Properties of Water. Boiling-point. Heat of Vaporization. The Freezing of Water. Heat of Fusion of Ice. Heat of Condensation of Steam and of Solidification of Water. Superheating and Supercooling of Water.

The Vapor-tension of Water in its Different States of Aggregation.

The Temperature-pressure Diagram of Water. The Phase Rule. Other Physical Properties of Water. Solvent Power of Water. Unsaturated, Saturated, and Supersaturated Solutions. Limited and Unlimited Solubility. Properties of Water affected by Dissolved Substances. The Dissociating Power of Water.

Hydrogen Dioxide. Preparation and Purification. Properties of Hydrogen Dioxide. Hydrogen Dioxide a Good Oxidizing Agent. Hydrogen Dioxide also a Reducing Agent. Catalytic Decomposition of Hydrogen Dioxide. Relations of Water and Hydrogen Dioxide.

Chapter VI

Combining Numbers and Atomic Weights. Chemical Methods of determining Combining Numbers. Molecular Weights determined from the Densities of Gases. Avogadro’s Hypothesis. Avogadro’s Hypothesis and Molecular Weights. Atomic Weights from Molecular Weights. Atomic Weights from Specific Heats. Isomorphism an Aid in determining Atomic Weights. Most Accurate Method 0f determining Atomic Weights. Table of Atomic V eights.

CONTEXTS xi

Chapter VII Pack

Determination of the Molecular Weights of Gases and of Dissolved Substances 82

Densities and Molecular Weights. Method of Dumas. The Method of Gay-Lussac. Hofmann’s Modification of the Gay-Lussac Method.

The Gas-displacement Method of Victor Meyer. Method of Bunsen. Results of Vapor-density Measurements. Abnormal Vapor-densities, Apparent Exceptions to the Law of Avogadro. Explanation of the Abnormal Vapor-densities. Dissociation of Vapors diminished by an Excess of One of the I*roducts of Dissociation.

The Law of Mom Actum. The Work of Guldberg and Waage.

Molecular Weight s of Dissolred Substances. Determination of the Molecular Weights of Dissolved Substances by the Freezing-point Method. Apparatus devised by Beckmann. Method employed by Beckmann. Determination of the Molecular Weights of Dissolved Substances by the Boiling-point Method. Boiling-point Method of Beckmann. Carrying out a Molecular Weight Determination with the Beckmann Apparatus. Boiling-point Apparatus of Jones.

CHAPTER VIII 1 Osmotic Pressure and the Theory of Electrolytic Dissociation . 100

Osmotic ITessure. Demonstration of Osmotic Pressure. Morse’s Method of preparing Se in i permeable Membranes. Measurement of Osmotic Pressure.

Relations between Osmotic Pressure and Gas-pnssurr. Boyle’s Law for Osmotic Pressure. Gay-Lussac's Law for t binotic Pressure. Avogadro’ s Law applied to the Osmotic Pressure of Solutions. Causes of Gas-pressure ami Osmotic Pressure. Exceptions to the Appiica- • bility of the Gas Laws to Osmotic Pressure.

Origin of the Theory of Klectrolytie Dissociation. The Problem as it was left by Van’t Hoff. Work of Arrhenius. The Theory of Electrolytic Dissociation. Measurement of Electrolytic Dissociation. The Conductivity Method. Method of measuring the Conductivity of Solutions. Calculation of the Dissociation from Conductivity Measurements.

Chapter IX

Chlorine an Element or a Compound. Occurrence and Preparation of Chlorine. Chemical Properties of Chlorine. Action of Chlorine on Hydrogen. Action of Chlorine on Water. Action of Chlorine on Certain Organic Compounds. Chloriue Hydrate. Certain Physical Properties of Chlorine. Liquefaction of Chlorine. Comparative Inactivity of Dry Chlorine. Hydrochloric Acid. Volume Relations in which Hydrogen and Chloriue combine. Preparation of Hydrochloric

XU

CONTEXTS

PAGE

Acid. Chemical Properties of Hydrochloric Acid. Definition of an Acid. Detection of Hydrochloric Acid. Physical Properties of Hydrochloric Acid. Aqueous Solution of Hydrochloric Acid. Thermochemistry of Hydrochloric Acid.

Compounds of Chlorine with Oxygen and Hydrogen. Compounds of Chlorine with Oxygen. Compounds of Chlorine with Oxygen and Hydrogen. Ilypochlorous Acid. Properties of Ilypochlorous Acid. Calcium Hypochlorite. Chlorine Monoxide. Chloric Acid. Properties of Chloric Acid. Chlorates. The Chlorine Ion and the Ion of Chlorates. Perchloric Acid. Properties of Perchloric Acid. Chlorine Septoxide. Chlorine Dioxide and Chlorous Acid. Power of Chlorine to combine with Oxygen. Valency. Faraday’s Law the Basis of Chemical Valence.

Chapter X

Hypothesis of Prout. The Triads of Dobereiner. The Octaves of Newlands. The Periodic System of MendeltSeff, Lothar Meyer, and Brauner. Chemical Properties and Atomic Weights. Combining Power. Relations within the Groups. Basic and Acid Properties. Physical Properties and Atomic Weights. Atomic Volumes. Old Atomic AVeights corrected and New Elements predicted by Means of the Periodic System. Imperfections in the Periodic System. General Scheme to be followed.

' CHAPTER XI

Bromine , Occurrence and Preparation. Chemical Properties of Bromine. Detection of Bromine. Bromine Atoms and Bromine Ions. Physical Properties of Bromine. Ilydrobroinic Acid. Properties of Ilydrobromic Acid. Compounds of Bromine with Oxygen and Hydrogen. Bromic Acid. Compound of Bromine witli Chlorine.

Iodine, Occurrence and Preparation. Chemical Properties of Iodine. Detection of Iodine. Detection of Iodine in the Presence of Bromine and Chlorine. Physical Properties of Iodine. Hydriodic Acid. Compounds of Iodine with Oxygen and Hydrogen. Compounds of Iodine with Chlorine. Compound of Iodine with Bromine.

Fluorine, Occurrence and Preparation. Chemical Properties of Fluorine. Physical Properties of Fluorine. Hydrofluoric Acid. Compound of Fluorine Yvith Iodine. Comparison of the Several Acids formed by the Halogens.

Chapter XII

Occurrence and Purification. Chemical Properties of Sulphur. Physical Properties of Sulphur. Vapor-density of Sulphur. The Temperature-pressure Diagram of Sulphur.

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PACK

Compounds of Sulphur with Hydrogen. Hydrogen Sulphide. Chemical Properties of Hydrogen Sulphide. Reversible Chemical Reactions. Acid Sulphides. Dissociation of Hydrogen Sulphide. Physical Properties of Hydrogen Sulphide. Hydrogen Persulphides.

Compounds of Sulphur with Oxygen and Hydrogen. Sulphur Dioxide. Sulphurous Acid. Strength of Sulphurous Acid. Sulphur Trioxide. Properties of Sulphur Trioxide. Sulphuric Acid. Chemical Properties of Sulphuric Acid. Physical Properties of Sulphuric Acid. Dissociation of Sulphuric Acid. Scientific and Technical Uses of Sulphuric Acid. Other Compounds of Sulphur with Oxygen and Hydrogen. Thiosulphuric Acid. Hyposulphurous Acid. Pyrosulphuric Acid or Disulphuric Acid. Persulphuric Acid. Polythionic Acids.

Compounds of Sulphur with the Ilulogens and Oxygen. Compounds of Sulphur with Chlorine. Compounds of Sulphur with Chlorine and Oxygen.

CHAPTER XIII Selenium and Tellurium 197

Selenium. Compounds of Selenium. Tellurium. Compounds of Tellurium.

Chapter XIV

Occurrence and Preparation. Chemical Properties of Nitrogen. Physical Properties of Nitrogen.

Compounds of Nitrogen with Hydrogen. Ammonia. Chemical I’roperties of Ammonia. Composition of Ammonia. Physical Properties of Ammonia. Liquid Ammonia. Ammonium. Ammonium Amalgam. Hydrazine. Properties of Hydrazine. Triazoic Acid.

CHAPTER XV Neutralization of Acids and Rases 210

Ammonium Hydroxide. Rases are Hydroxyl Compounds. Acidity of Rases and Basicity of Acids. Indicators. Theory of Indicators.

Salts. Heat of Neutralization. Explanation of the Constant Heat of Neutralization of Strong Acids and Strong Rases. Neutralization of " ea^ Acids and Rases. Explanation of the Results with Weak Acids and Rases. Explanation of the Law of the Thermoneutrality of Solutions of Salts.

Compounds of Xitrogtn with Oxygen and Hydrogen. Ammonium Hydroxide. Measurement of the Dissociation of a Weak Rase like

XIV

PAGE

Ammonium Hydroxide. Law of Koldrausch. Hydroxylamine. Compounds of Nitrogen with Oxygen. Nitrous Oxide. Nitric Oxide. Nitrogen Sesquioxide or Nitrogen Trioxide. Nitrogen Dioxide or Nitrogen Peroxide. Nitrogen Pentoxide. Acid Compounds of Nitrogen with Oxygen and Hydrogen. Hyponitrous Acid. Nitrous Acid. Nitric Acid. Chemical Properties of Nitric Acid. Physical Properties of Nitric Acid. Detection of Nitric Acid. Dissociation of Nitric Acid and Nitrates. Fuming Nitric Acid. Aqua Regia.

Compounds of Nitrogen with the Halogens. Compounds of Nitrogen with Chlorine and Bromine. Compound of Nitrogen with Iodine. Compounds of Nitrogen with Oxygen, Hydrogen, and Sulphur. Nitrosyl Sulphuric Acid.

CHAPTER XVI The Atmospheric Air and Certain Rare Elements occurring in it 235

The Atmospheric Air. Composition of the Atmosphere. Is the Air a Mixture or a Compound ? Physical Properties of Atmospheric Air. Liquid Air.

Argon , Helium , Krypton , Neon , Xenon. Argon. Number of Atoms in the Molecule of Argon. Helium, Neon, Krypton, and Xenon.

Chapter XVII

Occurrence and Preparation. Properties of Phosphorus. Yellow Phosphorus. Red Phosphorus. Metallic Phosphorus. White Phosphorus. Compounds of Phosphorus with Hydrogen. Compounds of Phosphorus with Oxygen and Hydrogen. The Acids of Phosphorus. Orthophosphoric Acid. Dissociation of Phosphoric Acid. Detection and Determination of Phosphoric Acid. Pyrophosphoric Acid. Metaphosplioric Acid. Hypophosplioric Acid. Phosphorous Acid. Metaphospliorous Acid. Hypophosphorous Acid. Strengths of the Acids of Phosphorus.

Compounds of Phosphorus with the Halogens. Phosphorus Trichloride. Phosphorus Pentachloride. Phosphorus Oxychloride.

Chapter XVIII

Occurrence and Preparation. Properties of Arsenic. Compound of Arsenic with Hydrogen (arsine), AsHg.

Compounds of Arsenic with Oxygen and Hydrogen. Compounds of Arsenic with Oxygen. Arsenic Trioxide. Arsenic Pentoxide. Arsenious Acid. Arsenic Acid. Compounds of Arsenic with the Halogens. Compounds of Arsenic with Sulphur. Sulpho-salts of Arsenic.

XV

Chapter XIX Page

Antimony 2(51

Occurrence and Preparation. Properties of Antimony. Compound of Antimony with Hydrogen(stibine), Sbil*.

Compound# of Antimony rrilh Oxygen and Hydrogen. Oxides of Antimony. Acids of Antimony. Compounds of Antimony with the Halogens. Compounds of Antimony with Sulphur. Compounds of Antimony with Sulphur and the Metals. Hard Lead.

Chapter XX

Occurrence and Properties. Compounds of Bismuth with Oxygen and Hydrogen. Bismuth Chloride. Bismuth Sulphide.

Chapter XXI

Vanadium, Columbium, Neodymium, 1'ba-kodymium. Tantalum . . 270

Vanadium. Columbium. Praseodymium and Neodymium. Tantalum.

Chapter XXII

Allotropic Forms of Carbon. Amorphous Forms of Carbon. 'Hie Different Forms of Carbon contain Different Amounts of Energy. Physical Properties of Carbon.

Compound# of Carbon. Compounds of Carbon with Hydrogen. Compounds of Carbon with Oxygen. Carbon Monoxide. Thermochemistry- of Carbon Monoxide. Water-gas. Carbon Dioxide. Preparation of Carbon Dioxide. Chemical IToperties of Carbon Dioxide. Reduction of Carbon Dioxide by Plants. Physical lh-operties of Carbon Dioxide. Critical Temperature and Critical Pressure. Continuity of Passage from the Liquid to the Gaseous State. The Kinetic Theory of Liquids. Compounds of Carbon with Oxygen and Hydrogen. Compounds of Carbon with the Halogens. Compound of t arbon with Sulphur. Compound of Carbon with Nitrogen (cyanogen). Hydrocyanic Acid. Cyanic and Sulphocyanic Acids.

The Role of Carbon in producing Light. Illumination. Candle and Oil-lamp. Coal-gas. Water-gas. Flames and their Luminosity. Bunsen Burner, Blowpipe. Effect of cooling the Flame. The Acetylene Light. The Welsbach Light. The Electric Light. Measurement of the Relative Intensities of Light.

XVI

Chapter XXIII

The Element Silicon. Silicon Hydride or Hydrogen Silicide. Silicon Dioxide. The Acids of Silicon. Dialyzer. Crystalloids and Colloids. Metasilicic Acid. Polysilicic Acids. Conversion of Silicates into Carbonates. Compounds of Silicon with the Halogens. Compound of Silicon with Carbon — Carborundum.

CHAPTER XXVII The Alkali Metals — Lithium, Sodium, Potassium, Rubidium, and C/ESIUM

Occurrence of the Element Sodium. Preparation of Sodium. Properties of Metallic Sodium.

Compounds of Sodium with Oxygen and Hydrogen. Sodium Hydride. Sodium Peroxide. Sodium Hydroxide. The Chemistry of Sodium the Chemistry of the Sodium Ion. Compounds of Sodium with the Halogens. Sodium Chloride. Purification of Sodium Chloride. Sodium Bromide, Sodium Iodide. Sodium Hypochlorite, Chlorate and Bromate. Sodium Triazoate and Sodium Amide. Sodium Nitrate. Sodium Nitrite. Sodium Hydrosulphide and Sodium Sulphides. Sodium Sulphite. Sodium Sulphate. Acid Sodium Sulphate and Sodium Pyrosulphate. Sodium Thiosulphate. Sodium Carbonate. The Le Blanc Method. The Solvay or Ammonia Process. Acid Sodium Carbonates. Hydrolysis of the Carbonates. The Phosphates of Sodium. Sodium Ammonium Phosphate. Sodium Borate or Tetraborate. Sodium Silicate. The Sodium Salt of Pyroantimonius Acid. Sodium Acetate. Sodium Cyanide. Spectrum of Sodium.

PAfiK xvxi

Chapter XXVIII Pack

POTA89IIM 343

Occurrence and Preparation. 1‘roperties of Potassium. Potassium Hydride. Potassium Peroxide. Potassium Hydroxide. Compounds of Potassium with the Halogens. Potassium Chloride. Potassium Bromide. Potassium Iodide. Potassium Fluoride. Potassium Chlorate. Potassium Perchlorate. Potassium Hydrazoate and Potassium Amide. Potassium Nitrate. Gunpowder. Potassium Nitrite. Compounds of Potassium with Sulphur. Compounds of Potassium with Sulphur and Oxygen. Potassium Sulphate. Potassium Carbide. Potassium Carbonate. Acid or Primary Potassium Carbonate. Phosphates of Potassium. Silicates of Potassium. Potassium Silicofluoride. Potassium Pyroantimoniate. Potassium Cyanide. Potassium Sulphocyanate. Oxalates of Potassium. Detection of Potassium.

Chapter XXIX

Lithium, Discovery, Preparation, and 1‘roperties. Compounds of Lithium. Rubidium, Occurrence, Prqantion, and Properties. CotnjK)unds of Huhidium. CMhm, Occurrence, Compounds. Ammonium. Ammonium Hydroxide. Ammonium Chloride. Ammonium Hydrazoate or Triazoate. Ammonium Nitrite. Ammonium Nitrate. Ammonium Hydroeulphide, Sulphide, and Polysulphides. Ammonium Sulphate. Ammonium Carbonate. Phosphates of Ammonium. Characteristics of the Alkali Metals in General.

CHA1*TER XXX

Caicium, Occurrence, Preparation, and Properties. Calcium Oxide or Lime. Calcium Hydroxide or Slaked Lime. Compounds of Calcium with the Halogens. Calcium Hypochlorite — Bleaching Powder. Sulphides of Calcium — Calcium Hydrosulphide. Calcium Sulphate. Calcium Carbide. Calcium Carbonate. Primary or Acid Calcium Carbonate. Phosphates of Calcium. Calcium Silicate. Glass. Varieties of Glass. Calcium Oxalate. Detection of Calcium.

Strontium. Occurrence, Preparation, and Properties of Strontium.

Salts of Strontium. Detection of Strontium.

Barium. Oxides of Barium. Barium Hydroxide. Barium Chloride. Barium Sulphate. Barium Carbonate. Barium Phosphates.

< tther Insoluble Compounds of Barium. Detection of Barium. Detection of the Alkaline Earths — Calcium, Strontium, and Barium.

Chapter XXXI Page

The Magnesium Group — Glucinum, Magnesium, Zinc, Cadmium, Mercury

Glucinum. Magnesium. Magnesium Oxide and Magnesium Hydroxide. Magnesium Chloride. Magnesium Sulphate. Magnesium Carbonate. Phosphates of Magnesium. Silicates of Magnesium.

Other Compounds of Magnesium. Separation of Magnesium from the Elements of the Calcium Group.

Zinc. Zinc Oxide and Hydroxide. Zinc Chloride. Zinc Sulphide.

Zinc Sulphate. Zinc Carbonate.

Uses of Zinc in Primary Batteries. Demonstration of the Solution-tension of Metals. The Relative Solution-tensions of Some of the More Common Metals. Solution-tension of Metals and Primary Cells. Concentration Element. The Daniell Cell.

Cadmium. Salts of Cadmium.

Mercury. Properties of Mercury. Amalgams. Molecular Weights of Metals in Mercury. Mercurous and Mercuric Oxides. Mercurous and Mercuric Chlorides. Mercuric Bromide and Iodide. Mercuric Sulphide. Mercurous and Mercuric Sulphates. Mercuric Cyanide. Action of Ammonia on Salts of Mercury. Variable Valence.

Chapter XXXII

The Earth Metals — Aluminium and the Rare Elements, Scandium, Gallium, Yttrium, Indium, Lanthanum, Ytterbium, Thallium, and Samarium 407

Aluminium, Occurrence and Preparation. Properties of Aluminium. Alloys of Aluminium. Aluminium Amalgam. Aluminium Oxide. Aluminates. Aluminium Chloride. Aluminium Sulphide. Aluminium Sulphate. The Alums. Aluminium Carbide and Carbonate. Silicates of Aluminium. Applications of Aluminium Silicates. Porcelain. Detection of Aluminium.

Scandium. Gallium. Yttrium. Indium. Lanthanum. Ytterbium. Thallium. Samarium.

Chapter XXXIII

Iron, Occurrence and Preparation. Properties of Iron. Impure or Commercial Iron. The Thomas-GUchrist Converter. Oxides of Iron. Ferrous and Ferric Compounds. Ferrous and Ferric Hydroxides. Ferrous and Ferric Chlorides. Sulphides of Iron. lerrous Sulphate. Ferric Sulphate. Potassium Ferrocyanide. Copper Ferrocyanide. Potassium Ferricyanide. Change in Color with Change in Electrical Charge. Other Salts of Iron. Ferrates.

xix

CHAPTER XXXIV Cobalt and Nickel

Cobalt. Cobaltous and Cobaltic Compounds. Oxides and Hydroxides of Cobalt. Cobaltous Salts. Double Cyanides of Cobalt. Double Nitrite of Cobalt. Action of Ammonia on Solutions of Cobalt Salts. Nickel. Compounds of Nickel.

t

CHAPTER XXXV Manganese . «.«••

Oxides of Manganese. Hydroxides of Manganese. Manganous Salts. Manganic Compounds. Tetravaient Manganese. Valence and Properties of Manganese. Manganous Acid. Manganic Acid. Permanganic Acid. Potassium Permanganate. Color of Permanganates.

CHAPTER XXXVI Chromiim

Oxides of Chromium. Hydroxides of Chromium. Valence and Properties of Chromium. Chromous Salts. Chromic Salts. Chromic Chloride. Chromites. Chromic Acid. Chromates. Dichromates.

m m

The Ions Cr< >« and Cr*0*. Chlorides of Chromic Acid. Perchromic Acid. Detection of Chromium.

CHAPTER XXXVII MOLTBUENI M, TrNGSTKN, Uranium

Oxides of Molybdenum. Molybdic Acid. Compounds of Chlorine with Molybdenum.

Tungsten. Chlorides of Tungsten. Tungstic Acid.

Uranium. Oxides of Cranium. Chlorides of Uranium. Uranium Radiation. Other Radiactive Substances.

Chapter Xxxviii

Occurrence and Preparation of Copper. Properties of Copper. Alloys of Copper. Oxides of Copper. Cupric Hydroxide. Chlorides of Copper. Cupric Chloride. Sulphides of Copper. Copper Sulphate. Cop]>er Carbonate. Other Copper Salts. Precipitation of Copper by Zinc. Another Method of Ion Formation.

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XX

Chapter XXXIX Page

Preparation of Silver. Properties of Silver. Colloidal Silver. Alloys of Silver. Silvering. Oxides and Hydroxide of Silver. The Silver Ion. Silver Chloride. Silver Bromide. Photography. Silver Iodide. Silver Nitrate. Silver Sulphide. Silver Sulphate. Silver Carbonate. Other Compounds of Silver.

Gold. Metallurgy of Gold. Properties of Gold. Oxides and Hydroxides of Gold. Salts of Gold.

Chapter XL

Occurrence, Preparation, and Properties of Lead. Precipitation of Lead by Metals. Oxides of Lead. Hydroxides of Lead. Chlorides of Lead. Iodide of Lead. Lead Nitrate. Lead Sulphide. Lead Sulphate. Lead Persulphate. Lead Carbonate. Lead Chromate.

Lead Acetate. The Storage Battery or Accumulator.

Tin. Preparation and Properties of Tin. Allotropic Forms of Tin. Alloys of Tin. The Tin Ions. Stannous and Stannic Oxides. Stannous and Stannic Hydroxides. Stannous Chloride. Stannic Chloride. Sulphides of Tin.

CHAPTER XLI Ruthenium, Rhodium, Palladium, Osmium, Iridium, Platinum . . 489

Ruthenium. Radium. Palladium. Osmium. Iridium. Platinum. Properties of Platinum. Uses of Platinum. Colloidal Solution of Platinum. Oxides and Hydroxides of Platinum. Chlorides of Platinum. Sulphides of Platinum. Double Cyanides of Platinum.

PRINCIPLES OF

INORGANIC CHEMISTRY

Introduction

The Study of Nature. — The study of nature is not limited to the world in which we live, but to the universe of which our world forms only a very small j»art. The study of the various asj>ects of nature, or natural science, forms the greatest and most comprehensive chapter of human knowledge. Indeed, so great is the field of natural science and so different the methods which are employed in studying nature, that no one mind can comprehend more than a small part of what has already been learned.

Natural science can, however, 1* subdivided into a number of branches, which are all related, but which possess inherent differences sufficient to distinguish the one from the other, and in some cases these differences are quite marked.

Astronomy has to do chiefly with the study of the motions and relations of bodies as a whole in the universe, while physics, chemistry, geology, and biology are concerned primarily with phenomena which manifest themselves on the earth. Of these, physics and chemistry are far more closely allied than they are to geology — the science of the formation of the surface of the earth, or to biology — the science of living matter.

Relations between Chemistry and Physics. — While it is impossible at this stage to give a comprehensive conception of the relations and differences between chemistry and physics, certain fundamental distinctions can be jwinted out.

Connect a piece of copper with an electric battery, and an electric current will flow through it. The copper while carrying the current has properties which are different from copj>er through which no electricity is passing. Disconnect the copper from the electric battery, and it possesses its original properties.

Heat a piece of copper gently, and some of its properties are changed. It will givo out heat to surrounding objects; it will

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o occupy a larger volume when hot than at ordinary temperatures. Allow the copper which has been warmed to cool, and it will possess again its original properties. Changes of this kind are known as physical.

If, on the other hand, we heat a piece of copper to redness in the presence of the air, a far more fundamental change takes place. The copper disappears and a black substance is formed which has properties quite different from the original copper. The black substance does not look like a metal. It cannot be drawn out into wire. It weighs considerably more than the original copper, and in general has properties sufficiently different from the original copper to show that we are dealing with an entirely different substance. If the black powder is now cooled to the original temperature of the copper, it retains its own characteristic properties.

It is obvious, therefore, that by heating to a sufficiently high temperature in the presence of the air, the copper has been transformed into something else, and that the new substance is not retransformed into copper when the original temperature is again restored.

The change effected in the latter case is, then, far more fundamental than in the former. While certain properties of the copper were changed by passing an electric current through it, or by gently warming it, these properties were restored again when the current was interrupted, or when the temperature was allowed to fall. The original copper remained copper. In the latter case, however, the composition of the substance teas changed, and this is characteristic of chemical activity. The substances which react chemically lose many of their characteristic properties, and give rise to new substances with very different properties.