None
It is sometimes difficult to discriminate between the two reactions ; in some cases authorities differ and no generally accepted definitions to distinguish clearly between them seem to exist ; but when reactions do not take place exactly simultaneously with the passage of the current and in exact proportion to it, or when they continue after the current ceases, they are unquestionably secondary. The author suggests that in view of the fact that some energy changes are generally involved in all chemical and electrochemical reactions, a primary reaction may be said to be the one whose energy (endothermic or exothermic) appears in the electric circuit, while a secondary reaction is one whose energy does not appear in the electric circuit. C. H. Appendix m CONVERSION FACTORS USED IN ELECTRO- CHEMICAL CALCULATIONS Taken from Hering's ** Conversion Tables." Length. 1 centimeter - 0.3937 inch 1 inch - 2.640 centimeters Surface, 1 sq. inch 1 sq. decimeter 1 sq. decimeter 1 sq. foot Volumes. 1 cb. centimeter 1 cb. centimeter 1 cb. inch 1 quart lUter lUter 1 gallon 1 gallon 1 cb. foot 1 cb. foot Weights or Masses. 1 gram 1 pennjTweight (troy) 1 omice (advp.) 1 ounce (troy) 1 pound (advp.) Hologram Weights and Volumes, 1 pound per gallon 1 kilogram per liter 6.452 sq. centimeters 16.60 sq. inches 0.1076 sq. foot 9.290 sq. decimeters ImilliUter 0.06102 cb. inch 16.39 cb. centimeters 1.101 Uters 1.067 quarts (U. S.; liquid) 0.2642 gallon (U. S. ; Uquid) 3.786 Uters 0.1337 cb. foot 28.32 Uters 7.481 gaUons (U. S. ; Uquid) 16.432 grains 1.666 grams 28.36 grams 31.10 grams 0.4636 kUogram 2.206 pounds (avdp.) 0.1198 kilogram per Uter 8.346 pounds per gaUon 120 CONVERSION FACTORS 121 Water. lUter » 2.206 pounds 1 gallon » 8.345 pounds 1 cubic foot - 62.43 pounds 1 pound » 0.4636 Uter 1 pound « 0.1198 gallon 1 pound - 0.01602 cb. foot 1 kilogram « 0.2642 gallon Energy (heal). 1 joule s 0.2389 gram calorie 1 thermal unit (BTU)»1 262.0 gram calories 1 watt-hour = 0.8600 kg. calorie 1 kg. calorie » 3.968 thermal units 1 kg. calorie = 1.163 watt-hours. Power. Iwatt » 0.2389 gram calorie ] 1 gram calorie per second s 4.186 watts 1 horse-power » 0.7467 kilowatt 1 kilowatt = 1.341 horserpowers Electrochemical Equivalents in Energy (other than those given in Table I). Grams per watt-hour » 0.0373 x Kilograms per horse- power-hour » 0.0278 X Pounds per kilowatt- hour - 0.0822 X Pounds per horse- power-hour = 0.0613 X Watt-hours per gram » 26.8 x Kilowatt-hours per pound » 12.2 X Horse-power-hours = per kilogram = 36.0 x Horse-power-hours per pound » 16.3 x < atomic weight change of valence x volts change of valence x volts atomic weight 122 ELECTROCHEBflCAL EQUIVALENTS Electrochemical energy. For monovalent ions : Volts - kilogram calories per gram moleeule x 0.0434 For multivalent ions divide the volts thus obtained by the valence Electrolytic deposits. 1 gram per sq. deci« meter » 0.02048 pound per sq. foot 1 poimd per sq. foot » 48.82 grams per sq. decimeter 1 pound per year » 0.002738 pound per day (of 24 hours) 1 pound per year 0.0008624 1 gram per minute 1 pound per day (of 24 hours) 0.1826 short ton per year 1 gram per minute 1160. poimds per year 1 short ton per year - 5.476 pounds per day 1 pound per hour » 4.383 short tons per year (day of 24 hours) (The year is considered to be 8664 days.) c. a Appendix IV GLOSSARY The numbers refer to the pages on which the definitions or explanations will be found. Adduction 106, 117 <* at anode. 5, 57, 117 Affinity, chemical 117 Anions 56 Anode 54, 113 Atom 112 " vs. ion 58 Atomic weight 114 Atomicity 29 Avogadro's law 2 Binary electrol3rtes 59 Bivalent 2 Bond 92 positive and negative 99 tmit 93 « IC Cathode 64, 113 " particle 74 " rays 73 Cations 56 Change of valence 97 Charge, miit 64, 93 Chemical affinity 117 Chemical equivalents. 63, 116 Coefficient 113 Combinations, chemical. 112 Conductance, electronic. 86 Copper coulometer 68 Corpuscle 78 Coulomb 31, 66 Coulometer 66 Diatomic 2 Direction of current 86 Di-valent 2,96 Electrochemical constant 64, 66 '' equivalent 66 Electrodes 54, 113 Electrolysis 54, 113 Electrolyte 53, 54, 56 Electron 78 Electrons, valence 79 Element 112 Endothermic 110 Equations, chemical 113 Equivalent, chemical 116 Exothermic 110 Faraday, the 3, 29, 93 Faraday's law 3, 5, 62, 64 Formula weight 114 Fourth state of matter 74 Fundamental law for gases 1, 9, 23, 29 Gram-atom 116 Gram-ion 31, 116 Gram-molecule 116 Ion 56 " vs. atom 58 Joule 110 123 124 GLOSSARY Migrations of ions 66, 60 Molecular weight 114 Molecule 112 Mon-atomic 2 Mono-valent 96 Negative valence 99 Non-electrolytes 64 Non-valent 96, 97 Oxidation 106, 117 <' at anode .. 6, 67, 117 Poles 64 Primary reactions 118 Quaternary electrolyte ... 69 Radiant state of matter ... 74 Radical 112 Reactions 113 " primary 118 « secondary ... 66, 118 Reduction 101, 117 << at cathode 6, 67, 117 Relative weights 114 Salts 24 Secondary reactions. .66, 118 Sign of valence 99 Silver coulometer 66 Subscripts 112 Ternary electrolyte 69 Titration coulometer 71 Tri-valent 96 Unit bond 98 « charge 64 Valence 6, 86, 93, 94, 116 change of 4, 97 electrons 79 negative 99 number of electrons 86 sign of 99 unit charges 64 vs. valency 97 zero 6, 96, 97 Valency 97 Valent, non- 96, 97 Voltameter 66 Volume coulometer 69 Water coulometer 69 Zero-valence 6, 96, 97 INDEX « II <l « Adduction, defined. 105, 117 *^ again 106 « atanode.5, 57, 117 ** examples 42, 46 « sign of valence 99 AfBnity, defined 117 " 110 Ampere-hours per cubic foot 23 " " per gram.. 12 per liter ... 23 per pound. 12 Anions, defined 55 Anode, defined 54, 113 « consumption of. 33 ** reaction 57 Atom, defined 112 " of electricity 84,79 " stability of 82 " structure of 79 " vs. ion 58 Atomic weight, defined. 114 " " table 12 Atomicity 29 Atoms, number of 86 " constitution of 80 Avogadro's constant 9 ** law, defined. 2 B Battery, depolarizer 36, 37 « poles of 55 *' storage 45 Binary electrolyte 59 Bivalent 2 Bond, defined 92 <i II Bond 86 « non-electrolytic 96 '* positive and negative 99 " strength of 109 « unit 93 Bunsen cell 39 Bureau of Standards cou- lometer 67 Calculations, method of. 28 Calories 110,121 Cathode, defined 54, 113 " particle 74 rays, defined ... 73 << deflection. 75 " reaction 57 Cations, defined 56 Change of sign of valence 48, 50, 101 Change of valence, defined 4,97 examples 36, 37, 43, 48 Table I 8 Charge, free 104 magnitude 77 on electron 86 ratio to mass .... 76 value of; 78, 79 unit 64,93 Charged ions 58 Chemical affinity, defined  " 82, 91 " reactions, defined 101 " " 112 Chemistry, elementary prin- ciples 112 Coefficients, defined 113 " ignored 39 Combination heat 109 Combinations, defined. 112 '* • of elements, table IV 24 Combining capacity 84 Compounds, chemical. ' 24 Conductance, electronic. 85 Conduction, electrolytic. 93 Conductors, class of 63 '* second class. 86 Conversion factors 120 Copper anode 33 " chloride 38 " coulometer 68 Corpuscles 78 Coulomb, defined 31, 66 Coulombmeter, see coulome- ter 66 Coulombs per cubic cm. 23 '* per milligram. 12 Coulometer, defined 66 ** Bureau of Stand- ards 67 " copper 68 " silver 66 " titration 71 " volume 69 " water 69 " weight 66 Cubic cm. per coulomb. 23 '* feet per 1000 amp. hrs.23 Current, direction of 86 '* electronic stream 86 D Decomposition voltage. 110 Depolarizers 33, 36, 37 Description of tables 7 Diaphragm 66 Diatomic 2 Direction of current 86 Discharge in vacuum 73 Dissociation theory 67 *< ** appUed 103 Di-valent 2, 96 '< element 83 Double duty, of acid 61 " " of current. 46 Drop, volume of a 78 £ Electricity is not energy. 12,21 per kilowatt-hour 12 Kilowatt 121 Kilowatt-hours per kilogram 12 It Non-conductor 53 Non-electrolytes 54 Non-valent 95, 97 Nucleus, positive 79 O Organic compounds non- conductors 54 Oxidation, defined. .106, 117 ** again 105 << at anode 6, 57, 117 '* examples 42, 46 « sign of valence. 99 Oxygen, weight of liter 9 Liter of hydrogen, weight. 83 Liter of oxygen, weight ... 9 Liters per ampere-hour ... 28 M Manganese peroxide 87 Mass, ratio to charge 76 Matter, fourth state of 74 Metallic conductance .... 86 Methane, oxidized 101 Migration 66, 60 « speeds of 61 Milligrams per coulomb. 12 Molecular layer 56 *' weight, defined. 114 Molecules, defined 112 Mon-atomic 2 Mono-valent 96 " ions 122 N Negative charge flows 108 " «* sign 58 " valence 87, 99 " " example 48,60 Nitric acid reduced 101 P Poles, defined 54 Positive charge flows 108 « « mass of. 80 " " sign of... 58 ** " size of... 80 " nucleus 79 Pounds per 1000 amp. hrs. 12 « per kilowatt-hour. 12 Practical valences 106 Primary battery 84 *' reactions, defined 118 Quaternary electrolytes. 69 R Radiant state of matter ... 74 Radical, defined , 112 i " electrochemical I constant of. 48 Reactions, defined 113 \ << chemical; 101 1 *' intermediate.. 40 " involved 41 " primary and sec- ondary, def'd 118 INDEX 129 Reactions, secondary, de- fined 56 " secondary example 41 Reduction, defined. 101, 117 " 99 " a gain 103 << a loss... 101,104 '' at cathode 6, 67, 102, 117 Reduction, conception of. 103 <' example 42 Relative weights, defined. 114 Salts 24 Second class conductors. 85 Secondary reactions, defined 56, 118 « « example 41 Sign of valence 6, 99 « " " example. Table IV 24 <c 130 INDEX OF AUTHORS C( (< (( Valency, defined 97 91 a property 97 vs. valence 97 Valenty non- 96, 97 Velocity of cathode particles 74 Voltage of decomposition . 110 Voltameter, defined 66 Volume coulometer 69 W Water coulometer 69 Watt-hours 110 '* per gram 12 per pound 12 it Zero valence 5, 95, 97, 98 '* '* example ... 49, 98 Zinc in battery 34 INDEX OF AUTHORS Arrhenius 58 Bates 71 Blanchard 59 BoemsteiQ 9 Bureau of Standards VI, 7, 67 Clarke 7 Comstock 87 Cox 87 Crookes 73 Daneel 71 Falk 105 Faraday 54, 62 Friend 87 Getman 105 Hamlm 105 Heimrod. . 66 Bering ... .V, 93, 97, 102, 120 Jones 59 Kohlrausch 70 Landolt 9 Le Blanc 56 MeUor 94 Mendeleef 83 Millikan 78 Nelson 105 Nicholson 80 Oettel 68 Perrin 74,86 Ramsay 84, 87 Richards, J. W... VI, 24, 106 Richards, T. W 66 Smith 94 Stokes 78 Talbot 59 Thomson, J. J 74, 79, 87 Troland 87 Washburn 71 Wilson 77 ,y^. 