Glass Q J3 A-S’ Book .H 75Z, Gojyriglif}!? /31 COPYRIGHT DEPOSIT V> LABORATORY EXERCISES AND PROBLEMS IN GENERAL CHEMISTRY BY B SMITH HOPKINS PROFESSOR OF CHEMISTRY, UNIVERSITY OF ILLINOIS AND HARVEY aV"' NEVILLE t ASSOCIATE PROFESSOR OF CHEMISTRY, LEHIGH UNIVERSITY Revised Edition D. C. HEATH AND COMPANY BOSTON NEW YORK CHICAGO ATLANTA SAN FRANCISCO DALLAS LONDON C ^ A :*\\ 1 A 5' ' \ ' ACKNOWLEDGMENT In the development of these exercises the authors are indebted to the members of the Division of Inorganic Chemistry of the University of Illinois for many helpful suggestions. In general, the experiments are the result of the teaching experience in this laboratory. Copyright, 1931 By D. C. Heath and Company 3 1 1 ©CIA 44412 PRINTED IN U. S. A. OCT 24 1931 CONTENTS PART I-THE NON-METALS EXERCISE PAGE General Laboratory Rules. 1 Suggestions for Writing Laboratory Notes. 2 Procedure for the First Laboratory Period. 3 1. The Use of Glass Tubing. 4 2. Measurement — The Metric System. 6 Laboratory Technique. 7 3. Properties of Matter — Chemical and Physical Change 10 4. Elements, Compounds — Separation from Mixtures. 11 5. Study of a Mixture. 12 6. Chemical Change. 13 7. Sources of Oxygen. 14 8. Catalysis. 15 9. Preparation of Oxygen; Combustion — Formation of Acids and Bases. 15 10. Accurate Weighing. 17 11. Weight of a Liter of Oxygen — Law of Constant Compo¬ sition . 19 12. Methods of Preparing Hydrogen. 21 13. Preparation and Properties of Hydrogen. 22 14. Hydrogen as a Reducing Agent. 23 15. Weight of Metal to Displace a Gram Atom of Hydrogen 24 16. Water — Boiling and Freezing Points — Purification. 26 17. Some Properties of Water—Solutions. 27 18. Hydrogen Peroxide. 28 19. The Law of Multiple Proportions. 30 20. Solubility — Supersaturated Solution. 31 21. Hydrates. 32 22. Formula of a Hydrate . 33 23. Colloidal Solutions. 34 24. Gels. 36 25. Double Decomposition or Metathesis. 37 26. Preparation and Properties of Chlorine. 38 27. Hydrogen Chloride — Hydrochloric Acid. 39 28. Potassium Hypochlorite. 41 29. Potassium Chlorate. 42 30. Potassium Perchlorate . 42 31. Bleaching Powder. 43 32. Ionization. 44 33. Ionization and Chemical Action. 45 iii iv CONTENTS EXERCISE PAGE 34. Electrolysis of a Salt Solution. 46 35. Hydrolysis . 46 36. Bromine. 47 37. Iodine. 48 38. Hydrogen Fluoride (Hydrofluoric Acid). 49 39. Preparation of Pure Sodium Chloride from Rock Salt 50 40. Atomic Structure. 51 41. The Per Cent of Oxygen in the Air. 52 42. Ammonia — Preparation; Properties. 53 43. Nitric Acid — Preparation and Properties. 54 44. Reduction Products of Nitric Acid. 56 45. Nitrous Oxide. 57 46. Nitrites — Nitrous Anhydride. 58 47. Sulfur — Allotropic Forms. 58 48. Sulfur — Combination with Metals; Hydrogen Sulfide 59 49. Hydrogen Sulfide — Properties and Uses. 60 50. Sulfur Dioxide — Preparation; Properties. 61 51. Sulfuric Acid. 63 52. Sodium Thiosulfate. 64 53. Normal Solutions — Equivalent Weights. 65 54. Normal Solutions — Acidimetry. 66 55. Phosphorus. 67 56. Arsenic and Antimony. 69 57. Bismuth. 70 58. Silicon . 71 59. Boron. 72 60. Carbon. 73 61. Identification of a Salt. 74 62. A Review of Oxidation-Reduction. 75 PART II —THE METALS 63. The Physical Properties of the Metals. 77 64. Properties of Alloys. 78 65. The Chemical Properties of the Metals. 82 66. Properties of Sodium. 84 67. Preparation and Properties of Sodium Hydroxide .... 86 68. Hydroxides of the Metals . 88 69. Sodium Bicarbonate and Sodium Carbonate. 89 70. Preparation of Potassium Nitrate. 91 71. Uses of Some Potassium Compounds. 93 72. Ammonium Compounds. 94 73. Tests for Potassium, Sodium, Ammonium Salts. 96 74. Soap. 97 75. Emulsions. 99 76. Cuprous Compounds.101 77. Preparation of Some Cupric Compounds.102 78. Metallic Couples.104 CONTENTS V EXERCISE PAGE 79. Electrochemical Action.105 80. Silver.107 81. Reactions of Calcium, Strontium, and Barium.109 82. Hard Water.Ill 83. Magnesium.112 84. Zinc and Cadmium. 114 85. Mercury.115 86. The Preparation of Mercuric Thiocyanate.117 87. Aluminum.119 88. Qualitative Analysis of Baking Powder.121 89. Tin.122 90. Lead.124 91. Chromium.126 92. Preparation of Chrome Alum.127 93. Manganese.129 94. Iron — Ferric and Ferrous Compounds.130 95. Corrosion of Iron.131 96. Preparation of Double Salts.132 97. Cobalt. 133 98. Nickel.134 99. Unknown No. 5 — “Group Unknown”.135 100. Unknown No. 6 — “General Unknown”.136 PART III —CHEMICAL ARITHMETIC Types of Problems.141 Appendix.1^1 LIST OF SUPPLIES The following is an estimate of the quantities of material and apparatus advisable to purchase for a class of ten students who perform all the experiments in the manual. The amounts listed are generous to allow for waste of chemicals and reason¬ able breakage of apparatus. In certain experiments requiring the use of the analytical balance or other limited equipment it will be found advisable not to have all the students perform such experiments in the same period. GENERAL APPARATUS 10 asbestos mats, 10 cm. X 10 cm. 1 balance, analytical, with weights and rider for weighing from 0.1 mg. to 100 g. 2 balances, platform, with weights for weighing from 0.1 g. to 1000 g. 1 barometer 10 brushes, test-tube 10 burners, Bunsen 10 clamps, iron, small 10 clamps, iron, large 1 gross corks, assorted sizes 1 set cork borers, 6 in set 10 crucibles, iron, diam. 4 cm. 24 crucibles, porcelain, #00 10 cylinders, porcelain, unglazed, diam. 3 cm. 24 dishes, porcelain, evaporating, 8 cm. 6 electrodes, carbon, diam. 5 mm. 10 files, triangular, 15 cm. 10 pr. forceps, iron, 10 cm. 15 squares gauze, iron wire, asbestos center, 12 cm. X 12 cm. 10 holders, test-tube 5 magnets, horse-shoe, small 5 magnifiers or lenses VI LIST OF SUPPLIES vii 10 meter sticks, graduated in inches on reverse side 10 mortars, porcelain, with pestle, 9 cm. 10 pks. paper, filter, qualitative, 13 cm. 2 pks. paper, filter, qualitative, 20 cm. 12 vials each, paper, litmus, red and blue 12 pinch cocks, Mohr's, medium 1 m. platinum wire, #25 10 racks, test-tube 10 sponges 10 spoons, iron, deflagrating, diam. of bowl 1 cm. 10 spoons, porcelain, spatula end, 15 cm. 10 stands, filter 10 stands, iron, with 2 rings 1 kg. stoppers, rubber, assorted sizes #0-6, one- and two-hole 10 thermometers, chemical, 0°-250° C. 10 triangles, pipestem, to support crucible #00 10 tripods, iron, diam. of ring 10 cm. 10 troughs, gas-collecting — unless sinks are adapted to this purpose 10 m. tubing, rubber, for Bunsen burners, inside diam. 6 mm. 7 m. tubing, rubber, soft, inside diam. 5 min'. 2 voltmeters, student type 10 wing tops for Bunsen burners GLASSWARE 24 beakers, 100 cc. 24 beakers, 150 cc. 24 beakers, 250 ce. 20 beakers, 400 cc. 12 beakers, 600 cc. 12 boats, porcelain, small 50 bottles, wide-mouth, 250 cc. 12 bottles, wide-mouth, 500 cc. 10 burettes, 50 cc. 15 flasks, Erlenmeyer, 250 cc. 15 flasks, Florence, 100 cc. 15 flasks, Florence, 500 cc. 12 funnels, 60°, 6.5 cm. 12 funnels, 60°, 9 cm. 12 graduates, 10 cc. or 25 cc. viii LIST OF SUPPLIES 12 graduates, 100 cc. 12 pipettes, 10 cc. 50 plates, glass, 8 cm. X 8 cm. 12 plates, cobalt glass, 8 cm. X 8 cm. 0.5 kg. rods, glass, diam. 4 mm. 12 tubes, calcium chloride, 15 cm. 12 tubes, test, hard glass, 15 cm. X 15 mm. 12 tubes, test, soft glass, 18 cm. X 25 mm. 15 doz. tubes, test, soft glass, 15 cm. X 20 mm. 15 tubes, thistle, 25 cm. stem, 5 mm. diam. 10 tubes, U, diam. 1 cm. 4 m. tubing, hard glass, combustion, diam. 15 mm. 2 kg. tubing, soft glass, medium walls, outside diam. 6 mm. 24 watch glasses, diam. 8 cm. This list does not include reagent bottles for desks and side shelf. The size and number of such bottles will be dependent upon the number of students taking the course. CHEMICALS 0.5 kg. acid, acetic, 30% 100 g. acid, fluosilicic 5 kg. acid hydrochloric, sp.gr. 1.19 5 kg. acid, nitric, sp.gr. 1.42 100 g. acid, perchloric 5 kg. acid, sulfuric, sp.gr. 1.84 50 g. acid, tartaric 2 1. alcohol, ethyl, 95% 25 g. agar, flake 100 g. aluminum, sheet or wire 100 g. aluminum chloride 0.5 kg. aluminum sulfate, cryst 200 g. ammonium carbonate 0.5 kg. ammonium chloride 5 kg. ammonium hydroxide, sp.gr. 0.9 50 g. ammonium molybdate 100 g. ammonium nitrate 100 g. ammonium oxalate 100 g. ammonium sulfate 50 g. antimony, powd. LIST OF SUPPLIES IX 100 g. antimony trichloride 100 g. arsenic trioxide 200 g. barium chloride 100 g. barium nitrate 25 g. bismuth 50 g. bismuth trichloride 100 g. bromine 50 g. cadmium nitrate 2 kg. calcium carbonate, marble chips 100 g. calcium magnesium carbonate, dolomite 0.5 kg. calcium chloride, anhydrous, granular 100 g. calcium fluoride, powd. 100 g. calcium nitrate 1 kg. calcium oxide, quicklime, in tin can 0.5 kg. calcium phosphate, bone ash 0.5 kg. calcium sulfate, gypsum, powd. 1 kg. calcium sulfate, plaster of Paris, fine 0.5 kg. carbon disulfide 0.5 kg. charcoal, animal 100 g. charcoal, wood, powd 200 g. chromic anhydride 100 g. chromium nitrate 100 g. cobalt nitrate 0.5 kg. copper sheet, 1 mm. thick 1 kg. copper turnings 1 spool copper wire #24 100 g. cupric chloride 100 g. cupric nitrate 100 g. cupric oxide, powd. 1 kg. cupric sulfate, blue vitriol 0.5 kg. ether 200 g. glucose 200 g. hydrogen peroxide, 3% 50 g. iodine, resublimed 200 g. iron filings 200 g. iron nails, small 1 spool iron wire, piano 100 g.