LABORATORY NOTES 
 
 NON-METALS. 
 
 ARRANGED FOR THE USE 
 
 OF 
 
 STUDENTS 
 
 IN 
 
 GENERAL CHEMISTRY 
 
 BY 
 
 EDGAR F. SMITH AND HARRY F. KELLER. 
 
 n 
 
PHILADELPHIA. 
 
 PRESS OF EDWARD STERN & Co. 
 
 3 r > 33 & 35 'N. TENTH ST. 
 
 1890. 
 
LABORATORY NOTBS. 
 
 NON-METALS. 
 CHAPTER I. 
 
 APPARATUS, MANIPULATIONS AND OPERATIONS. 
 
 (1) The Bunsen burner and the blowpipe. 
 
 i. Make a borax bead. 2. Dissolve some manganese dioxide in it. 
 j. Heat in the oxidizing flame. 4. In the reducing flame. 5. Heat oxide 
 of lead on charcoal in the reducing flame. 6. In the oxidizing flame. 
 
 (2) Working with glass tubing and rods. 
 
 i. Cut various lengths of rods and tubing. 2. Round the sharp edges 
 by softening and turning the ends in the lamp. 
 
 (3) Construct a wash-bottle (Fig. /). 
 7. Soften a sound cork by rolling it under your foot on 
 a clean floor. 2. Bore two parallel holes through it by 
 means of a cork-borer. These perforations should be cyl- 
 indrical and of less diameter than the glass tubes they are to 
 receive. Use a rat-tail file in enlarging them. j. Cut 
 suitable lengths of glass tubing. ^. Draw the longer one 
 to a fine point after softening in the flame. 5. Bend the 
 tubes in an ordinary fish-tail burner, and round the sharp 
 edges. 6. Fit the different pieces together. 
 
 (4) Arrange some other form of apparatus for practice. 
 
 (5) The balance. 
 
 i. Weigh an object by placing it on the left-hand pan of the balance, 
 and a weight judged about equal on the right-hand pan. Should the latter 
 be found too heavy, replace it by the next smaller one ; if too light, by the 
 next heavier one. Then add systematically the smaller weights, until the 
 needle points to the middle of the scale. The final adjustment is made 
 with the rider. In adding or removing weights, the supports must always 
 be raised. 
 
 (6) Measuring vessels. 
 
 i. Measure off 10 cc. of water (a) in a cylinder, (b) in a burette, (c] in 
 a pipette. Always read the lower meniscus. 2. Measure off similarly 50, 
 100 and 200 cc. of water, and determine their weight, j. Measure the vol- 
 ume of 5ogrms. of oil of vitriol, and of 65 grms. of muriatic acid. What 
 are the specific gravities of these substances ? Note the relation between 
 weight and volume in the metric system. 
 
 (7) Chemical operations : Solution, evaporation, crystallization, precip- 
 itation, filtration, washing and drying. 
 
 7. Place into a test tube pure sodium carbonate, into another cobalt 
 chloride, and add distilled water to each. Stir. What occurs ? 2. To cal- 
 cium carbonate, add water. Is there any change ? Now add a little hydro- 
 chloric acid. What action has it? j. Pour some strong hydrochloric 
 acid upon powdered manganese dioxide ; observe appearance and 
 o lor. Note, too, in each case, whether heat has any effect. Distinguish 
 
between chemical and mechanical solution. /. Heat the cobalt chloride 
 and the calcium carbonate solutions in porcelain dishes on an iron plate, 
 until the liquids are completely driven off (?). 5. Dissolve potassium chlo- 
 rate in hot water, and allow to stand and cool (?). 6. To a portion of the 
 above cobalt chloride solution, add a solution of soda ; boil. 7. Allow to 
 settle and filter. S. Wash the precipitate until pure water runs through the 
 filter (?). 9. Heat the filter until perfectly dry. 
 
 CHAPTER II. 
 
 GENERAI y PRINCIPLES. 
 
 (i) Changes in matter. 
 
 i. Rub a glass rod with a piece of cloth, then touch particles of paper 
 with it (?). 2. Through an insulated spiral of stout copper wire pass a cur- 
 rent from two Bunsen cells. Place a piece of wrought-iron a nail will 
 answer inside the spiral, and bring iron filings in contact with it. What 
 happens ? Interrupt the current and note the result ; repeat, j. Heat 
 a platinum wire in the non-luminous flame ; is there any change ? What is 
 the effect of removing it ? 
 
 Are the original properties of the substances in the above experiments 
 altered, after the action of the forces of electricity, magnetism and heat has 
 been stopped? 
 
 ^r. Mix intimately four parts, by weight, of finely powdered sulphur 
 with seven parts of very finely divided iron (filings). Pass a magnet over a 
 portion of the mixture. Another portion treat with carbon disulphide in a 
 test tube. Then heat the remainder in a tube over a gas flame. Note 
 carefully what occurs in each case. Powder the mass resulting 
 from the last operation in a dry mortar. Can you extract from 
 it any iron with a magnet, or dissolve out any sulphur with car- 
 bon disulphide ? What inference do you draw from the facts 
 observed ? 5. Moisten a bright piece of iron with water and 
 expose it to the action of the air for a few hours. 6. Decompose 
 water in Hofmann's apparatus by an electric current. The 
 water should be acidulated with sulphuric acid to make it a 
 conductor of electricity. A current from four to six Bunsen cells is 
 required. To the gas, of which a larger volume has collected, apply a 
 flame, and to the other a glowing spark. 7. Heat oxide of mercury in a 
 tube of hard glass {Fig. 2). Apply the spark test. 8. Rub some sulphur 
 and mercury together in a mortar. 9. Heat sugar in a dry test tube, at 
 first gently, and then more strongly. Note color and odor. 10. Mix 
 dry soda and tartaric acid in a mortar. Is there any action ? What occurs 
 when you add water ? 
 
 (2) Point out in what respect the changes involved in experiments /-j 
 differ essentially from those in 4-10. By what general names can you dis- 
 tinguish the two different kinds? With which does chemistry concern 
 itself? Define chemistry. 
 
 Through what agencies have the results been obtained in experiments 
 4-10 ? Has any gain or loss of matter occurred in any of them ? 
 
 (3) The products resulting from 6 and 7 cannot be further simplified, 
 i.e., decomposed into dissimilar substances. They are elements, What are 
 water and red oxide of mercury ? 
 
5 
 
 /. Dissolve in a little nitric acid, the black powder obtained by heating 
 an intimate mixture of powdered sulphur and copper filings. 
 
 <) 3- Evaporate the solution nearly to dryness, take up in water and 
 filter. What remains on the filter? Place the filtrate in a 
 beaker, dip the platinum electrodes of a battery into it (Fig. j}, 
 and allow the current to act for ten minutes. What do you 
 observe upon the platinum foil, forming the negative pole? 
 What changes have the copper and the sulphur undergone in 
 this experiment ? 
 
 (Study pp. 18-27, in Richter's Chemistry.) 
 
 (4) Metals and non-metals. (See Richter, p. 20.) 
 
 CHAPTER III. 
 HYDROGEN. H. 
 
 (i) Put several pieces of granulated zinc into a test tube and pour 
 dilute sulphuric acid upon them. What occurs ? 
 
 (2) Arrange the apparatus shown in Fig, 4.. 
 The flask should contain about 15 grms. of Zn, and 
 dilute H 2 SO 4 is poured through the funnel tube. 
 When all the air in the apparatus has been dis- 
 placed (ask for precautions!) collect six test tubes 
 full of the gas over water. 
 
 (3) What are its properties? Will it burn? 
 Support combustion ? Is it lighter than air ? 
 
 Connect the poles of a Bunsen battery (3 cells) with a thin platinum 
 
 wire. What happens ? 
 
 Now fill a beaker with the gas you have prepared, 
 and with the mouth down drop it over the glowing 
 .vire (Fig. 5). Result? 
 
 (4) 7. To learn what becomes of hydrogen 
 when it burns in air, arrange apparatus as in Fig. 6. 
 The gas is led from the evolution flask A t into a 
 bottle containing some concentrated H 2 SO 4 , and 
 then passes through a tube filled with pieces of 
 CaCl 2 . The gas which escapes is free from mois- 
 ture. Burn it under a cold glass jar. What do you 
 obtain ? 2. Fill a small flask with a mixture of one vol. of H and five vols. 
 of air ; cork ; invert the flask several times to mix the gases ; wrap a towel 
 around it and bring its mouth to a flame. Result ? 
 
 <$ ^~^r\ (& Hydrogen is not the only pro- 
 
 duct of the action of H 2 SO 4 upon Zn. 
 
 Pour some of the liquid remaining 
 in the flask, in which H was generated, 
 into a porcelain dish. Evaporate to 
 about one-third of the original bulk ; 
 allow to stand for some hours. You 
 will now discover that the solution is 
 full of colorless crystals. Thesfe are zinc sulphate or white vitriol a salt, 
 ZnSO 4 -f 7H 2 O. Write the equation of the reaction. 
 
(6) Determine the weight of H generated by a given weight of Zn. 
 
 A piece of Zn (not more than '02 grm. ) is accurately 
 weighed, and placed under a funnel in a beaker (Fig. 7). 
 The beaker is then nearly filled with water, so that the entire 
 funnel is under the surface. A test tube containing dilute 
 H 2 SO 4 is lowered over the stem of the funnel. Hydrogen 
 appears and collects in the tube. When all the Zn has dis- 
 appeared, * transfer the tube containing the H to a larger vessel, 
 holding water. Measure the volume of the gas by marking 
 the tube where the inner and outer levels of water are even, 
 and then weighing or measuring the quantity of water that it will hold to 
 that mark. Note the temperature of the water, and the height of the 
 barometer. 
 
 The weight of the H is found by multiplying the vol. by the wt. of 
 i cc., i. <?., '0000896 gr. Before this can be done, however, it is necessary to 
 reduce the volume of the gas to o C. and 760 mm. , as the above value has 
 been determined under these conditions. If v = volume observed, t = 
 temperature, and p = pressure, then 
 
 say 
 
 ' fs 
 
 (I + t) + 760 
 
 2 ) and W = v X '0000896 . '003665. 
 
 To calculate the quantity of Zn, necessary to generate a unit of H, we 
 
 Wt of H : Wt of Zn : : i : x. 
 x here stands for the equivalent weight of Zn. 
 
 The equivalent weights of some other metals, such as Fe, Cd, Mg, can 
 be determined in the same manner. 
 
 . Problems. /. How much H can be obtained from Zn 
 
 and 299 grms. of H 2 SO 4 ? 2. How much Znand H 2 SO 4 are 
 necessary to furnish 100 grms. of H ? j. Suppose you have 
 found that '15 grms. of Mg yield 15*2 cc. of H at 20 C. and 
 750 mm., what is the equivalent weight of that metal ? 
 
 (7) Decompose water by electrolysis and test the pro- 
 ducts. 
 
 (8) Take a small piece of sodium, wrap it in paper and place it, with 
 forceps, under the mouth of a test tube filled with water, and inverted in 
 
 water (Fig. 8} contained in a dish. 
 Repeat this until the test tube is filled 
 with the gas. Test it for H. 
 
 What becomes of the metal ? Write 
 the reaction. 
 
 (9) Construct the apparatus shown 
 in Fig. 9. 
 
 Water is heated to boiling in the 
 flask A, and the steam led over iron 
 filings or wire, heated to redness in a tube of hard glass. Care must be 
 
 1 This may be hastened by b inging a spiral of platinum wire in contact with the Zn. 
 2 ) Tension of aqueous vapor is here neglected. 
 
taken to prevent steatn from condensing in any part of the tube. Collect 
 the escaping gas over water. Test it for H. 
 Is the iron changed ? Equation ? 
 
 , t /o (10) Into a weighed tube of hard glass put 
 
 a weighed quantity of CuO ; connect the tube 
 with a CaCl 2 tube of known weight (Fig. id}. 
 Pass a current of dry H over the CuO and heat. 
 After the change is complete, cool and deter- 
 mine the loss in weight of tube -\- CuO, and 
 the gain in the CaCl 2 tube. Explain the reaction. 
 
 Problems. /. How many cc. of H can be obtained from 2 grms. of 
 Na? 2. How many grms. of H 2 O can be decomposed by 5 grms. of Fe ; 
 by how much is the weight of the latter increased ? j. 10 grms. of CuO will 
 yield how much Cu upon heating in H ? 
 
 Give a brief summary of what you have learned about H. 
 (Study Richter, pp. 39-47.) 
 
 CHAPTER IV. 
 
 FIRST NATURAL, GROUP OF ELEMENTS CHLORINE, BROMINE, IODINE, 
 
 FLUORINE. 
 
 CHLORINE. Cl. 
 
 i) Into a test tube put MnO 2 and HC1. Note what happens both 
 before and after heating. 
 
 (2) Use apparatus (shown in Fig. //) for preparing 
 larger quantities of Cl. The MnO 2 should be in the 
 form of small lumps (not powder). Heat the mixture 
 gently, pass the Cl through water and collect it either 
 by downward displacement or over warm water. 
 
 Write the reaction. How many atoms of Cl are 
 liberated ? How many molecules ? 
 
 (3) /. What is the normal condition of this element ? 
 2. Is it lighter than air ? j. Is it inflammable? ^. Does 
 it support combustion ? 
 
 To obtain answers to these questions, fill 5 test tubes with dry Cl, and 
 proceed as under H. 
 
 (4) Again fill 5 bottles with the dry gas. Cover them with glass plates. 
 Into / throw a little pulverized antimony. 
 
 Into 2 carefully introduce a piece of phosphorus. 
 
 Into 3 insert tissue paper moistened with oil of turpentine. 
 
 Into 4. introduce colored flowers. 
 
 Into 5 pour a little litmus solution. 
 
 What are the results ? 
 
 (5) Fill a small-sized flask one-half with chlorine, the other half with 
 hydrogen. Wrap a towel about the flask and apply a flame to its open 
 mouth (?). Care. 
 
 (6) Invert a bottle filled with Cl over water saturated with the same 
 gas. What follows in the course of a few hours' exposure to sunlight? 
 
8 
 
 Can you account for results in experiments /, 5 and 6 ? Why should the 
 gas be collected over warm water ? 
 
 (7) 7. Saturate water with Cl ; cool below o C. What do you obtain ? 
 2. Place some of the product in the closed limb of a 
 bent tube (Fig. 12] ; seal the open end. Now warm the 
 end containing the substance, in a water bath, to about 
 '/ 30, while you cool the other end in snow. What is the 
 
 liquid which collects in a ? What occurs when a is warmed and b is placed 
 in snow ? 
 
 (8) Determine the weight of a litre of chlorine. Arrange apparatus shown 
 in Fig. 13. 
 
 In the evolution flask place a mixture of equal 
 weights of salt and manganese dioxide. Add sul- 
 phuric acid, previously diluted with its own volume of 
 water (pour the acid into the water !). Heat gently, 
 and conduct the Cl into the perfectly dry flask c. 
 When this is filled, which you ascertain by the color 
 of the gas in the neck, slowly withdraw the tube and 
 cork the flask at once. Weigh the flask, and note the 
 atmospheric temperature and pressure. Determine, also, the weights of the 
 flask filled with air and with water. 
 Calculation : 
 
 Capacity of flask, a 
 
 Temperature, t 
 
 Pressure, p 
 
 Flask filled with air, ... w 
 
 Cl, w' 
 
 Wt. of a litre of air, i*293grm. 
 
 Cl, ;. x 
 
 The weight of the air filling the flask, ? X P + '001293 The differ _ 
 
 (i -f -00367^760 
 
 ence between this and w is the weight of the vacuous flask. Subtract this 
 from w'. The remainder is the weight of the Cl, (W). Reduce the vol. of 
 
 the Cl to o C. and 760 mm. (see under H) ; it is v = _ , and 
 
 WXiooo (i X -003671)760 
 
 the weight of i litre, x = w x I00 . 
 
 v 
 
 How much heavier is i litre of Cl than an equal vol. of H ? 
 
 Write the reaction involved in the above method for preparing Cl. 
 
 Problems. /. How many litres of Cl can be obtained from i kilo of 
 MnO 2 and HC1 ? 2. What weight of salt is required to prepare 100 litres of 
 Cl ? Write put your deductions from the above experiments on Cl. 
 
 (Read Richter, pp. 49-52.) 
 
 HYDROGEN CHLORIDE. HC1. 
 
 (i) Repeat the explosion of equal vols. of Cl and H. Quickly cover the 
 mouth of the flask, and immerse it under water. Does the latter rise ? Put 
 a drop of the liquid on the tongue and note the taste. Add some blue litmus 
 solution. Is there any change ? 
 
(2) The product of the union of H and Cl is a colorless gas. It is called 
 hydrogen chloride. It is usually prepared by the action of sulphuric acid 
 upon salt, thus : 
 
 2NaCl + H 2 SO 4 = 2HC1 -f Na 2 SO 4 . 
 or, better, NaCl -f H 2 SO 4 = HC1 -j NaHSO 4 . 
 
 The apparatus is the same as that used for making Cl (Fig. /j). 
 
 (3) Determine the properties of HCl as under H and Cl. 
 
 What new property appears here ? Fill a long dry glass tube with the 
 gas, and quickly bring it into a basin containing water colored blue with 
 litmus. What happens ? What does HCl gas yield on dissolving in water ? 
 
 (4) In the preparation of H by the action of Na upon water, it was 
 observed that the liquid became soapy to the touch, and acquired the 
 property of turning red litmus blue. Prepare such a solution. To it add a 
 few drops of litmus, and then an HCl solution (gradually) from a burette, 
 until the blue color just begins to turn. Evaporate the resulting liquid to 
 crystallization. Dissolve and recrystallize the product. It appears in cubes, 
 and has the taste of common salt. It does not affect either red or blue litmus. 
 We say it is neutral in reaction. The substance is chloride of sodium or 
 common salt. What is a salt ? An acid ? A base ? How can you obtain 
 HCl and Cl from NaCl ? 
 
 (5) Burn H in an atmosphere of Cl, and Cl in hydrogen. 
 
 (6) To determine the iveight of a litre of HCl, proceed exactly as under 
 chlorine. 
 
 (7) Determine the composition of HCl by volume. 
 
 1. Decompose concentrated HCl by means of the electric current in 
 Hofmann's apparatus. Carbon electrodes should be used here. Test the 
 two gases ; the H with a taper, and the Cl by bleaching a moist piece of 
 calico. After the action of the current has continued for some time, close 
 the stopcocks and note the relative volumes of the gases. 
 
 2. Fill a perfectly dry and graduated tube with HCl. Close the open 
 end with the thumb, and opening the tube for a moment, quickly pour in 
 about 10 cc. of sodium amalgam. Close the tube at once with the thumb, 
 slightly moist, and shake well. Invert the tube in a large beaker of water, 
 and remove the thumb. The amalgam will drop into the water, and the 
 latter will rush up into the tube, filling it nearly half full. Immerse the 
 tube so that the water in it and that in the beaker are on the same level. 
 This is done to measure the hydrogen under atmospheric pressure. Read 
 the residual volume of the gas and measure the volume of the mercury. 
 
 Calculation : 
 
 Capacity of tube, a 
 
 Vol. of mercury, b 
 
 Vol. of H, . c 
 
 c = a b 
 2 
 
 (8) Add a solution of HCl to solutions of silver nitrate ; of mercurous 
 nitrate ; and of lead acetate. What do you observe in each case ? Boil the 
 precipitate formed in the lead solution with water. Cool, and note result. 
 
10 
 
 BROMINE. Br. 
 
 (1) Allow a drop of bromine to fall upon a heated watch glass ; cover 
 it quickly with a beaker. What is the color of the vapor? Dissolve 
 bromine in alcohol, in ether, in carbon disulphide, and in chloroform. Note 
 the relative solubilities, and the color of each solution. 
 
 (2) 7. Pass Cl through an aqueous solution of K Br ; what happens ? 
 2. To one portion of the product add a few drops of CS 2 , and agitate the 
 
 mixture ; what is the result ? j. To another por- 
 J~ij f< t tion of the solution, containing free Br, add a few 
 
 drops of a starch solution. (This is made by boil- 
 ing starch with water and filtering). Result ? 
 
 (4) Devise a method for preparing bromine 
 from K Br. 
 
 (5) Prepare hydrobromic acid. In a small 
 flask cover i part of amorphous phosphorus with 
 2 pts. of H 2 O, and from a funnel, provided with a 
 
 stopcock, gradually allow 10 pts. of Br to run in. The gas is purified by con- 
 ducting it through a U-tube, containing moistened pieces of phosphorus and 
 glass. (Fig. 14.} 
 
 (6) Prepare AgBr, HgBr and PbBr 2 ; do they differ much from the 
 chlorides ? 
 
 IODINE. I. 
 
 (i) 7. Place an iodine crystal upon a warm plate, and note color of 
 vapor. 2. Test the solubility of iodine in various liquids ; what are the 
 colors of the resulting solutions ? 
 
 (2)7. Pass Cl through a solution of KI. Test the resulting liquid with 
 ether, carbon disulphide and starch solution (as with Br). 2. Repeat this 
 experiment, substituting Br-water for the Cl. Avoid excess of Cl as well as 
 Br (?). 
 
 What conclusion do you draw relative to the affinity of the halogens 
 for potassium from these experiments ? 
 
 (3) Pass hydrogen sulphide gas (H 2 S) into 50 cc. of water, and add 
 powdered iodine till the brown color no longer disappears. Warm, filter (?) 
 and distil the filtrate. The product is what ? 
 
 How is gaseous HI prepared ? 
 
 (4) Precipitate solutions of silver nitrate (AgNO 3 ), mercurous nitrate 
 (HgNO 3 ), lead nitrate (Pb(NO 3 ) 2 ),and mercuric chloride (HgCl 2 ) with KI. 
 
 FLUORINE. Fl. 
 
 (1) In a lead dish (or platinum crucible) place i gram of pulverized 
 fluor spar (CaFl 2 ). Add cone. H 2 SO 4 ; cover the dish or crucible with a 
 watch glass coated with paraffin, through which some characters have been 
 
 'drawn with a fine point. Heat gently for a few minutes. 
 What do you observe on removing the paraffin ? 
 
 (2) Can you liberate Fl from a fluoride ? 
 
 Problems. i. How much NaBr, H 2 SO 4 and MnO 2 are necessary to 
 produce i cu. metre of Br? 2. What per cent, of HI does a liquid contain, 
 which represents a solution of 50 litres of the gas in i litre of H 2 O ? 3. 10 
 grms. of CaFl 2 will give what weight of HF1 ? 
 
II 
 
 CHAPTER V. 
 
 SECOND NATURAL GROUP OF ELEMENTS OXYGEN, SULPHUR, 
 
 (Selenium, Tellurium}. 
 
 OXYGEN.- O. 
 
 (i) Preparation. i. Weigh the hard glass tube a (Fig. 75), and intro- 
 duce a xveighed quantity (about '5 grm.) of red oxide of mercury. Ignite 
 
 strongly ; collect the liberated gas, and measure 
 it. Weigh the tube with the residue. What 
 are the products of the ignition ? 
 
 Prepare more of the gas, as follows : Mix 
 equal parts of KC1O 3 and pulverized MnO 2 ; 
 heat in a tube of hard glass or small retort. 
 Collect the gas in bottles over water. (Fig. 16. ) 
 (2) Into No. .1 lower a piece of ignited 
 sulphur on a copper spoon. Note result. Add 
 water after the combustion. 
 
 Into No. 2 introduce a small piece of 
 burning phosphorus (care !). Proceed as in No. i. 
 
 Into No. 3 introduce ignited charcoal. Treat as before. Add now a 
 few drops of blue litmus to the contents of each vessel. Any change ? 
 
 Into bottle No. 4 introduce a fine watch spring, previously heated at 
 one end and dipped into powdered S. Result ? 
 
 Is oxygen heavier or lighter than air ? Has it color, taste, or odor ? 
 Will it burn ? Does it support combustion ? 
 
 What other methods can be used for preparing O ? 
 (3; Determine the iveight of a litre of O. 
 
 Arrange apparatus shown in Fig. 77 / a is a 
 tube of hard glass, whose weight is known ; it 
 contains a weighed amount of KC1O 3 (about 3 
 grm.). The bottle A is filled with water, b is a 
 clip and d a beaker. Open the clip, heat a to 
 bright redness, and receive the water displaced 
 by the O in d. When no more gas is evolved, 
 cool ; allowing the rubber tube to dip under the 
 water of the jar. Some of the water will be 
 drawn back into the bottle (?). Measure the volume of the water in d. Note 
 the temperature of the air, and the height of the barometer. Weigh a, 
 containing residue (KC1). 
 Calculation : 
 
 Weight of the tube, a 
 
 Weight of KC1O 3 and tube, b 
 
 Weight of KC1O 3 , b a 
 
 Volume of H 2 O collected, v 
 
 Barometric pressure, p 
 
 Temperature, t 
 
 Aqueous tension at t, p 7 
 
 Weight of KC1 and tube, c 
 
 v X (p V} , (b c) X looo 
 
 Vo ~ (i + -00367 t) X 76o 
 
 and 
 
12 
 
 Dissolve the residual KC1 in water, and to its solution add nitrate of 
 silver (?). How does KC1O 3 behave under like conditions ? 
 
 (4) Give a summary of your work upon O. 
 
 Problems. /. How much O, by wt. and vol., can be obtained from 54 
 grms. of HgO? 2. Heat will expel what vol. of O from 2-45 grms. of 
 KC1O 8 ? j. How much HgO is necessary to yield i cu. d. m. of O ? 4. How 
 many times is O heavier than H ? 
 
 OZONE. O 3 . 
 
 (1) Partly fill a straight eudiometer tube with oxygen, over a dilute solu- 
 tion of KI mixed with starch. Pass the spark for some time. What occurs ? 
 
 (2) Pour water on clean pieces of phosphorus to half cover them ; 
 invert a large, clean jar over this and allow to stand for several hours. 
 Test the air under the jar for ozone. 
 
 (Read Richter, p. 85-89.) 
 
 COMPOUNDS OF OXYGEN AND HYDROGEN. 
 
 WATER. H 2 O. 
 
 (i) Arrange the distillation apparatus (Fig. 18) and prepare about 100 cc. 
 of distilled water. Note its taste and odor. Test it for chlorides with AgNO 3 ; 
 
 for nitrates and organic matter. Does 
 it leave a residue upon evaporation ? 
 What -action has it on litmus ? 
 
 Apply all these tests to a natural 
 water (except rain). 
 
 (2) /. Heat a little vegetable mat- 
 ter in a dry test tube. 2. Heat fresh 
 meat in the same manner, j. Care- 
 fully heat crystals of zinc or copper 
 sulphate in a test tube. What hap- 
 pens in these experiments ? ^. Expose clear crystals of sodium phosphate, 
 on a watch crystal, to the air. 5. Do the same with pieces of calcium 
 chloride. Results ? 
 
 (3) Determine the quantitative composition of water. 
 
 1. The composition of water by weight follows from the experiment of 
 reducing oxide of copper, described under H. 
 
 2. The relative volumes, with which O and H unite to form water, are 
 determined either by analysis or synthesis. The former has been per- 
 formed in electrolyzing water. 
 
 3. Fill a eudiometer (Fig. so) with water. Through a rubber tube admit 
 about 50 cc. of O and then a like volume of H. (If the eudiometer is 
 
 not graduated, mark these with rubber bands). Close 
 the open end with your thumb, leaving some air to serve 
 as a cushion beneath it, and pass the spark. Remove 
 the thumb, and pour in enough water to make the levels 
 equal in both limbs. What is the amount of the con- 
 traction ? What is the residual gas ? Test it. 
 
 (4) Determine the weight of a litre of steam. Con- 
 struct apparatus shown in Fig. 20. The flask a is closed 
 ^^Zr by a cork perforated with two holes ; one is about i cm. 
 wide, the other about 4 mm. wide. A short straight piece of glass tubing 
 
 Ay /y. 
 
passes through the wider hole, while the other receives the bent tube b. C 
 
 is an iron pot with a perforated lid, 
 through which passes the neck of the 
 flask. The bottom of the iron vessel is 
 covered with sand. A small glass tube 
 is weighed and rilled with water (not 
 more than '02 grm.). Heat the iron pot 
 with a Bunsen burner until the tempera- 
 ture is constant (?). Now drop the tube 
 containing the water through the wide 
 tube of the flask (the bottom of which 
 should be protected with a layer* of 
 asbestos) and quickly cork the wide tube. When the flow of water ceases, 
 make the levels of the water in the beaker and the bottle coincide. Uncork 
 the wide tube and remove the flame. 
 
 Measure the water and note the temperature and pressure of the air. 
 The calculation is analogous to that used under O. 
 (5) Perform experiment 2, p. 100 in Richter. 
 
 How many volumes of steam result from the combination of 2 vols. of 
 H and i vol. of O ? 
 
 What is the molecular formula of water ? 
 
 HYDROGEN PEROXIDE. H 2 O 2 . 
 
 (1) Add moist hydrated barium peroxide to cold dilute H 2 SO 4 . Filter. 
 What does the filtrate contain ? 
 
 (2) /. Add a solution of KI, containing starch, to this liquid. Ferrous 
 sulphate may also be added to a portion of it. 2. Add a solution of 
 potassium permanganate to another portion (?). 
 
 COMPOUNDS OF OXYGEN AND CHLORINE. 
 
 (1) Make a dilute solution of caustic potash, and conduct chlorine 
 into it until the latter is no longer absorbed. Treat one portion of the 
 product with HC1, and another with H 2 SO 4 . What results ? 
 
 (2) Mix 20 grms. of quicklime with 50 cc. of H 2 O. After the slaking 
 is finished, conduct Cl into the mixture until it is no longer absorbed. 
 
 Add HC1 to one portion and H 2 SO 4 to a second portion. 
 What is set free ? Does it bleach ? 
 
 (3) Pass Cl into a warm concentrated solution of KOH till it ceases 
 to be absorbed. What separates upon cooling ? Recrystallize the product 
 from H 2 O. Will it give off O upon heating? Try the action of HC1 upon 
 a crystal. Allow a drop of cone. H 2 SO 4 to fall upon a small crystal and 
 warm gently (?). Care ! 
 
 Observe carefully the behavior of KC1O 3 upon heating (?). 
 
 SULPHUR. S. 
 
 (1) Wherein does sulphur differ from the elements previously studied ? 
 
 (2) Place a few grams of powdered S in a dry test tube, and heat gradu- 
 ally. Observe and describe the changes which occur. 
 
14 
 
 (3) Dissolve some S in CS 2 and allow to stand till the liquid has evapo- 
 rated. What remains ? 
 
 (4) Determine the sp. gr. of S (Fig. 21}. A small flask with narrow 
 neck is filled with water (boiled shortly before) to a mark upon the neck. 
 
 Weigh the flask, then place an additional 10 grm. weight upon the 
 right-hand pan of the balance and small pieces of S upon the left- 
 hand pan, until the pointer is again in the middle. Now introduce 
 the S into the flask. Carefully remove the water above the mark 
 and re-weigh the flask with its contents. The loss in weight will 
 represent the weight of a volume of water, equal to that of 10 
 grms. of S. The latter divided by the former is the quantity 
 sofight. 
 
 (5) Prepare the monoclinic modification of S by melting about 10 grms. 
 of the ordinary variety in a Hessian crucible. Cool ; and as soon as a solid 
 crust has formed upon the surface, pierce it and allow the still liquid portion 
 of the contents to run out. Note the shape of the crystals upon the sides 
 of the crucible. 
 
 (6) To obtain the plastic variety, heat 10 grams of S in a test tube 
 above 230 C., and poiir the mass into cold water. 
 
 Test the solubility of the product in CS 2 . Preserve a portion of it for 
 several days. Does it change ? 
 
 (7) To a strong solution of yellow potassium sulphide, add HC1. 
 What are the properties of the separated sulphur ? 
 
 Give a brief outline of the element sulphur ; contrast it with the pre- 
 viously studied elements. 
 
 SULPHUR AND HYDROGEN. 
 
 (8) Over some dry silver sulphide, contained in a tube of hard glass, 
 conduct a current of pure H. Apply heat. What remains in the tube ? 
 Note the odor of the escaping gas. as well as its action upon a piece of 
 paper moistened with a solution of acetate of lead. 
 
 (9) Hydrogen sulphide is formed only with difficulty from its elements, 
 but is readily obtained by the action of acids upon sulphides, thus : 
 
 FeS + 2H 2 SO 4 FeSO 4 + H 2 S orSb 2 S 3 -[- 6HC1 === 2SbCl 3 + 3H 2 S. 
 
 The apparatus to be used is the same as that employed in preparing 
 hydrogen. 
 
 (10) What are the properties of H 2 S? Is it soluble in water? Does it 
 burn ? What are its products of combustion ? Hold a porcelain plate in 
 the flame ; what results ? Pass the gas into solutions of chromic acid, per- 
 manganic acid, and ferric chloride. What changes are observed ? How do 
 these last-named reactions show its reducing power ? What happens to the 
 aqueous solution of the gas when exposed to the air ? What action has 
 the aqueous solution upon litmus ? To what class of compounds does it, 
 therefore, belong ? 
 
 (u) Pass H 2 S through solutions of the following salts, viz: CuSO 4 , 
 SbCl,, Pb (NO,) 2 , AsCl 3 , and Zn (C 2 H 3 O 2 ) 2 . Note results carefully. 
 Can sulphides be prepared in another manner ? (See Chap. II, $i) 
 
15 
 
 (12) Determine the composition of hydrogen sulphide, 
 
 Into a bent tube of hard glass, filled with mercury, 
 (Fig. 22) y introduce dry hydrogen sulphide. Place a 
 piece of tin in the bent portion, and heat it. Is the vol- 
 ume of the gas changed after the experiment, and what 
 becomes of the piece of tin ? Test the gas remaining in 
 the tube. Do your results enable you to deduce the 
 molecular formula of H 2 S? (See Richter, 3d ed., p. 
 
 in.) Trace the similarity between H 2 S and H 2 O. Write a summary of 
 
 your experiments on H 2 S. 
 
 AND CHLORINE. 
 
 (13) Sulphur Monochloride. Prepare this compound by conducting 
 dry chlorine over molten sulphur. The product which distils over is col- 
 lected in a dry test tube, kept cold by immersion in ice water. Re-distil 
 the product. Note its color and odor. Expose some of it to the air on a 
 watch glass. Add water to another portion contained in a test tube. Note 
 carefully what happens. Write the reaction. 
 
 SULPHUR AND OXYGEN. 
 
 (14) Burn sulphur in the air. Result? Burn FeS in the air. What 
 are the properties of the resulting compound. It is sulphur dioxide SO 2 . 
 
 (15) Fit a small flask as indicated in Fig. 23. Place 
 copper turnings in it, then addH 2 SO 4 (strong) through the 
 funnel tube. Warm. Is the product the same as that 
 obtained in 14? Is it soluble in water? Has the aqueous 
 solution the same properties as the gas ? 2. Pass some of 
 the gas into acidulated solutions of potassium dichromate 
 and potassium permanganate. Repeat these experiments 
 with the aqueous solution instead of the gas. What hap- 
 pens in each case ? j. Test the aqueous solution of SO 2 with 
 litmus. What is this solution commonly called? 4. Fill a 
 dry jar with SO 2 gas; introduce colored flowers. Note the result. 
 
 (16) What is the formula of sulphurous acid? How many series of 
 salts can it form ? How would you designate the different sodium salts ? 
 AddHClto a solution of Na 2 SO 3 . What follows? Evaporate the solu- 
 tion to dryness and examine the residue. What is it ? Write the reaction. 
 
 SULPHUR TRIOXIDE SO 3 and SULPHURIC ACID H 2 SO 4 . (Read Rich- 
 ter, p. 189.) 
 
 (17) /. Prepare sulphuric acid as described in Richter, p. 191. Study 
 the product carefully. 2. Dilute a portion of it with water ; what happens? 
 j. Test a portion of this diluted solution with litmus (?). 4. Another por- 
 tion neutralize with NaOH and evaporate. What is the residue ? Does it 
 contain any S ? Prove this. 5. Add BaCl 2 to a third portion of the solution. 
 What is the precipitate ? Is it soluble in water or in acids ? 6. What is the 
 action of strong H 2 SO 4 upon wood or paper? Explain the cause of this 
 action. 
 
 (18) How many series of salts can sulphuric acid form? Prepare 
 (NH 4 ) 2 SO 4 , Na 2 SO 4 , NaHSO 4 and CuSO 4 . (Read Richter, pp. 189-200.) 
 
i6 
 
 CHAPTER VI. 
 
 NITROGEN GROUP NITROGEN, PHOSPHORUS, ARSENIC, ANTIMONY 
 
 (and Bismuth}. 
 NITROGEN. N. 
 
 (i) Preparation. /. In a dish swimming on water place a piece of 
 phosphorus and ignite it ; invert a beaker glass over it (Fig. 24}. What 
 becomes of the P ? When the latter has ceased 
 burning, restore the level of the water, and note 
 the decrease in the volume of the air. Test the 
 residual gas with a burning taper. 2. Heat gently 
 in a small flask or retort a mixture of i part KNO 2 , 
 i pt. NH 4 C1, i pt. K 2 Cr 2 O 7 , and 3 pts. of H 2 O ; col- 
 lect the gas over water. Fill five bottles with this gas. 
 (2) Has it color, taste, odor ? Does it burn or 
 support combustion ? Introduce a small animal, e.g. , 
 a mouse, into one of the bottles ; what is the result ? 
 Is the gas heavier than air ? Does it unite readily with other elements ? 
 
 (3) Determine the weight of a litre of nitrogen. A round-bottomed 
 flask is fitted as shown in Fig. 25. Pour about 30 cc. of water into it, and 
 
 insert the cork to the mark. Boil the water, 
 while the clip is open, until all the air has been 
 expelled from the flask. This requires the steam 
 to blow out for about five minutes. Now close the 
 tube with the clip, and remove the flame. Cool 
 and weigh the flask. Read the temperature and 
 barometric pressure in the balance-room. 
 
 Connect the flask with the tube b of the aspira- 
 tor, containing N and arranged as in Fig. 26. The 
 rubber tube a is made to dip under water, and the 
 clip is gradually opened, allowing N to enter the flask. Now raise the 
 vessel containing the water into which the rubber tube dips, so that the 
 water in it is at a higher level than that in the aspirator. Close the clip. 
 Disconnect the flask and open the clip for a moment, to establish atmos- 
 pheric pressure in the flask. Weigh. The calculation is identical with that 
 given for O. 
 
 What is the ratio between the weights of equal vols. of N and H ? 
 
 (4) Is air a chemical compound? 
 
 How would you determine the weight of a litre of air ? 
 
 (5) Make an analysis of air by Hempel's apparatus. l 
 (Study Richter, pp. 116-125.) 
 
 NITROGEN AND HYDROGEN. 
 AMMONIA, 
 
 (6) Preparation : Heat an intimate mixture of finely powdered ammo- 
 nium chloride and caustic lime in a flask ; conduct the evolved gas through 
 a tube filled with small pieces of lime, and collect it in jars or test tubes 
 over mercury. 
 
 This analysis should be performed by the demonstrator. 
 
What is the object of the lime in the tube? Why can you not dry the 
 gas by passing it through H 2 SO 4 or CaCl 2 ? Why should it be collected 
 over mercury. 
 
 y i'o 27 (?) ^ s ammonia gas combustible? Does it 
 
 /~\ support combustion? /. Conduct NH 3 through a 
 
 t?// // ' S< 9 28 glass tube, and insert this into a wider tube filled 
 with oxygen (Fig. 27}. Apply a flame. The am- 
 monia gas will ignite and continue to burn. 2. 
 Heat concentrated ammonia water in a beaker 
 until there is an abundant disengagement of gas, 
 then conduct a rapid current of oxygen through 
 the liquid, and lower a glowing spiral of platinum 
 into the beaker (as in Fig. 28}. What happens ? 
 
 Note the order of NH 3 (caution !). Is it 
 lighter than air ? Soluble in water ? 
 
 (8) Prepare an aqueous solution of ammonia. 
 What are its properties ? 
 
 Add red litmus to some of the solution (?), and then neutralize carefully 
 with dilute HC1. Evaporate to dryness. Compare the product with the 
 ordinary NH 4 C1. Test it for Cl (?). Heat a little of it with sodium hydrate (?). 
 Heat another portion on a platinum foil (?). 
 
 (9) Determine the weight of a litre of NH$. 
 
 Fill a dry flask with the gas by tipward displacement, and proceed 
 exactly as under chlorine. What is the density of NH S ? 
 
 (10) To determine the quantitative composition of NH,, perform experi- 
 ments i and 2 on pp. 130 and 131, in Richter. 
 
 Write out a summary. (Read Richter, pp. 125-131.) 
 
 NITROGEN AND THE HALOGENS. 
 
 (u) Pour an alcoholic solution of iodine into strong ammonia water. 
 Collect the precipitate on a filter and wash it with water. Open the moist 
 filter ; tear it into small pieces and spread these on a board. After thej 
 have become dry, touch them with the end of a rod (?). Ask for instruc- 
 tions ! (Read Richter, pp. 132-133.) 
 
 NITROGEN AND OXYGEN. 
 
 (12) Hyponitrous oxide N 2 O. /. Place aboutsgrms. of ammonium 
 nitrate in a small retort ; add a little water, and apply heat. Collect the 
 product over warm water. 2. Test it with a glimmering chip ; j. with 
 burning phosphorus ; 4. with burning sulphur. 5. Mix equal volumes of 
 this gas and of H, and apply a flame. What other gas does it resemble in 
 its properties ? (Read Richter, pp. 212-213.) 
 
 (13) Nitric oxide NO. /. Pour dilute HNO ;J (sp. gr. 1-2) upon 
 copper turnings contained in an evolution flask. Cool, and allow the red 
 fumes, which form at first, to escape ; then collect the colorless product 
 over water. 2. What occurs when this gas comes in contact with the air ? 
 Is it the O or the N of the air that acts upon the gas ? j. Apply the tests 
 given under (12) to this gas (?). How can NO be distinguished from 
 oxygen? 4. Fill a cylinder with NO, and add a few drops of CS 2 , shake 
 
i8 
 
 well and bring a flame to the mouth of the vessel (?). 5. Pass a current of 
 NO into a strong solution of ferrous sulphate. What occurs? After the 
 solution has become saturated with the gas heat it to boiling (?). 6. Pass 
 the gas into a solution of potassium permanganate (?) . 
 
 (14) Nitrogen trioxide N 2 O 3 . (Read Richter, pp. 205-206.) 
 Nitrous Acid UNO 2 . (Richter, p. 206.) 
 
 (15) Nitrogen tetr oxide, N 2 O 4 , and dioxide, NO 2 . /. Heat 10 grams 
 of dry lead nitrate in a test tube ; condense the escaping vapors in a well- 
 cooled receiver. What are the vapors, and what is the condensed liquid > 
 Note the color. 2. What is the action of cold water, and of aqueous solu- 
 tions of the alkalies upon N 2 O 4 ? What do these reactions indicate in 
 respect to the composition of this compound? (Richter, pp. 207-208.) 
 j. What is its action upon potassium iodide ? 
 
 (16) Nitrogen pentoxide, N 2 O 5 . (Richter, p. 205.) 
 
 NITRIC ACID. HNO 3 . 
 
 /. Preparation. In a retort heat a mixture of sodium nitrate and sul- 
 phuric acid in proportions corresponding to the equation (?) : 
 NaN0 3 + H 2 S0 4 = NaHSO 4 + HNO 3 . 
 
 Collect the product in a cold receiver. 
 
 2. What are the physical properties of HNO 8 ? Color ? Odor ? Action 
 on litmus (diluted with H 2 O) ? j. What action has it on indigo ? Upon the 
 skin ? 4. Notice the effect of the acid upon the following metals: Cu, Fe, 
 Pb, Zn, Sn. Write the reaction for each one. 5. Cover powdered sulphur 
 with the acid, and warm (?). Dilute with water, filter, and test the liquid 
 with Bad 2 (?) 6. Introduce a piece of ignited charcoal into the acid. 
 What takes place ? 7. Add a few drops of HNO 3 to a solution of ferrous 
 sulphate (?) ; warm the solution (?). 
 
 (17) Determine the quantity of HNO Z in a solution, by Schultze's 
 method. 
 
 This method is based upon the following reaction : 
 
 HN0 3 4- 3 FeCl 2 + 3 HC1 = NO + 3 FeCl 3 . 
 
 We determine the quantity of NO which is formed, and calculate from it 
 the quantity of HNO 3 necessary to produce it. 
 
 Arrange the apparatus shown in Fig. 29. 
 
 Put the solution to be examined into the flask A, and concentrate it, by 
 boiling, to about 50 cc. While boiling, let the clips c and d be open, for 
 the escape of the steam. The cistern 
 B and the graduated tube D contain a 
 solution of NaOH (10 per cent.), which 
 has been boiled shortly before com- 
 mencing the experiment. After boil- 
 ing the contents of A, close clip c, 
 and let the steam escape at d. Finally 
 close this, and remove the lamp from 
 under the flask. A vacuum is now 
 produced within the flask, and the 
 rubber tubes d and c flatten in conse- 
 quence. While this operation has 
 been going on, a solution of ferrous chloride should have been prepared, by 
 
19 
 
 dissolving iron nails in strong HC1. This solution should be saturated. 
 Introduce 25 cc. of it into A. This is done by first filling the glass tube e 
 with water (by means of the wash bottle), then dipping it into the iron solu- 
 tion contained in a beaker and opening the clip d. The solution rapidly 
 passes into A ; close d in time to prevent the entrance of .air. Now care- 
 fully boil the liquid in A, and, as soon as the rubber tubes at and d become 
 distended, open c, so that the gases can pass over into D. CO 2 and steam 
 will be absorbed by the NaOH, while NO collects in the tube. When the 
 volume of the gas no longer increases, remove the graduated tube from the 
 delivery tube ; close it with the thumb, and transfer it to a large cylinder of 
 water, where the volume of the gas is read off. Note the temperature of the 
 water and the barometric ^pressure. 
 Calculation : 
 
 Observed vol. of the gas, - v 
 
 Vol. of gas at o C. and 760 mm., v 
 
 Barometric pressure, p 
 
 Temperature of water, t 
 
 Aqueous tension, p r 
 
 v _ vX(p-p x ) 
 
 (i + '00367 t) X 760 
 
 By multiplying v by 2-413 we obtain the N 2 O 5 in milligrams. Dividing 
 this product by the number of 100 cc. of water originally used, will give the 
 parts of N 2 O 5 in. 100,000 parts of the water. 
 
 Problems. (i) Required i cu. m. of N. How much air is to be deprived 
 of O ; and how much P must be burned, if 62 pts. of P unite with 80 pts. of O t 
 
 (2) How much HNO 3 , containing 46 per cent, of water, may be obtained 
 from 1,700 grms. of NaNO 3 , and how much water must be taken? 
 
 (3) How many grams of NH 3 will be absorbed by 5 litres of H 2 O, if 
 the latter absorbs 500 times jts volume of the gas? 4. Ten litres of water 
 having absorbed 700 times their volume of ammonia, what are the least 
 amounts of NH 4 C1 and CaO necessary for producing this solution ? 
 
 PHOSPHORUS. P. 
 
 (1) /. Determine the physical properties of the active and the red 
 varieties. 2. I,et a small piece of the active variety inflame in the air. 
 Will the red variety do this? j. Throw a small piece of the yellow 
 variety into ajar of dry Cl (?). Repeat with the red variety (?). 4. Bring 
 a small dry piece of active P in contact with iodine (?). 5. Heat a flask 
 containing a small piece of P and water until the former is melted, then 
 pass a current of oxygen through a delivery tube into the melted phos- 
 phorus (?). (Study Richter, pp. 133-136.) 
 
 PHOSPHORUS AND HYDROGEN. 
 
 (2) PAosphmePH 3 . /. Fill a flask almost full with a moderately- 
 concentrated NaOH solution. Add a few pieces of P, and heat carefully. 
 When the air in the neck of the flask has been expelled by the escaping 
 gas, insert a cork with a delivery tube, the other end of which dips under 
 warm water. What becomes of the gas as it escapes into the air ? 
 
 (Richter, pp. 136-139.) 
 
 Is there any similarity between PH 3 and NH 3 ? 
 
 (3) PHOSPHORUS AND THE HALOGENS. 
 
20 
 
 /. Pass a current of dry CO 2 gas into a retort, the bottom of which is 
 covered with dry sand. When all the air has been expelled, introduce some 
 well-dried pieces of P, and replace the CO 2 by a stream of dry Cl. Connect 
 the neck of the retort with a Liebig's condenser, and collect the product in 
 a receiver. It is phosphorus trichloride. What are its properties ? Pour 
 some of it into water (?). 
 
 2. Place a little PC1 3 in a dry test tube, and pass a stream of dry Cl upon 
 its surface. What is the result ? 
 
 PHOSPHORUS AND OXYGEN. (Richter, pp. 214-219). 
 
 (4) 7. Prepare phospho rus pentoxide, P 2 O 5 , by burning a carefully dried 
 piece of P under a dry bell-jar. 2. Drop a portion of the product into water (?). 
 
 (5) Orthophosphoric acid, H 8 PO 4 ; metaphosphoric acid, HPO 3 , and 
 Pyrophosphoric a^id, H 4 P 2 O 7 . How are these acids obtained? How many 
 series of salts are derived from them? By what names would you distin- 
 guish the different salts ? 
 
 /. Dissolve some Na 2 HPO 4 in water and test the solution with AgNO 8 , 
 FeCl 3 , and (NH 4 ) 2 MoO 4 . What do you observe in each case ? 2. Dissolve 
 fused Na 2 HPO 4 in water, and perform the same tests with its solution, j. 
 Heat salt of phosphorus (NaNH 4 HPO 4 ) until it no longer effervesces, and 
 dissolve the residue in water. How does this solution behave upon treating 
 with the above reagents ? 4. Acidify a portion of the last-named solution 
 with acetic acid, and add a solution of albumen to it. Result ? 
 
 (6) Phosphorus trioxideT? 2 Q 3y and phosphorous acid H 3 P 3 . 
 Pour PCI 3 into water. Evaporate the solution to syrupy consistency (?). 
 (Study Richter, p. 216). 
 
 ( 7 ) Hypophosphorous acid H 3 PO 2 . 
 
 Heat pieces of phosphorus in a porcelain dish with a moderately strong 
 baryta solution. When no more PH 3 is formed, cool, filter, and pass CO 2 
 into the solution until it shows a neutral reaction to litmus. Toward th 
 -end, the solution should be warmed. Filter and evaporate to suitable con- 
 centration. Hypophosphite of barium will crystallize. 
 
 How may the free acid be obtained from this salt ? 
 
 ARSENIC. As. 
 
 (i) Study the physical and chemical properties of this element. 
 {Richter, pp. 142 and 143.) Are they analogous to those of phosphorus? 
 
 (1) /. In a tube of hard glass heat a small piece of As to redness. 
 Result? 2. Heat As with the oxidizing flame upon charcoal (?). j. Dis- 
 solve powdered As in strong HNO 3 (?). 
 
 ARSENIC AND HYDROGEN. 
 
 (2) Perform Marsh's test for As. 1 
 
 Arrange the apparatus shown in 
 Fig- 30. To the mixture of Zn and 
 dilute H 2 SO 4 contained in a, add a 
 small portion of the solution to be tested 
 for As. The liberated gas contains H 
 and AsH 3 ' (arsine). It is passed 
 through c, filled with CaCl 2 (?), and 
 then through d, a tube of hard glass, contracted at several places. After 
 1 Ask for instructions ! 
 
21 
 
 all the air has been expelled from the apparatus, ignite the hydrogen. If 
 As is present it will burn with a bluish white flame, and white vapors will 
 be given off. Hold a cold porcelain plate in the flame (?). Heat the tube 
 d, as shown in the figure (?). 
 
 Great care must be exercised in performing this test, as the arsine 
 gas is extremely poisonous ! 
 
 ANTIMONY. Sb. 
 
 (i) Study this element in the same manner as As. Distinguish between. 
 SbH 3 and AsH 3 . 
 
 /. Treat the metallic mirror obtained in Marsh's apparatus, with a 
 freshly prepared solution of hypochlorite of sodium : As dissolves readily, 
 while Sb is scarcely acted upon. 2. Heat a piece of the tube, in which a 
 mirror has formed, in the flame of the Bunsen burner. Dissolve the pro- 
 duct in dilute, warm HC1, and add H 2 S water (?). j. Treat the spot formed 
 upon a cold porcelain plate with yellow ammonium sulphide, and evaporate 
 the solution at a gentle heat (?). 
 
 Problems. (i) How much P can be obtained from 250 grins, of bones ? 
 (2) 10 grms. of P give what vol. of phosphine? (3) What is the weight 
 of the product remaining, after evaporating a solution of 10 grms. of As in 
 HNO,? 
 
 CHAPTER VI. 
 
 CARBON GROUP CARBON AND SILICON. 
 
 CARBON. C. 
 
 (1) How many allotropic modifications of this element are known? 
 What are their principal properties ? /. Collect some NH 3 gas in a gradu- 
 ated tube over mercury ; introduce a piece of freshly-ignited charcoal, and 
 observe the diminution in the volume of the gas. 2. Boil a dilute litmus 
 solution with powdered animal charcoal ; filter. Result? j. Substitute 
 indigo for the litmus in the preceding experiment (?). 4.. Determine the 
 coke, volatile matter and ash in a sample of anthracite coal. 
 
 (Read Richter, pp. 150-152.) 
 * 
 
 CARBON AND HYDROGEN. 
 
 (2) Methane (Marsh gas) CH 4 . 
 
 /. Preparation. Heat a dried mixture of sodium acetate and sodium 
 hydrate in an iron tube. Collect the gas over water. Note its color, odor 
 and taste. Does it burn ? 2. Mix i vol. of it with 7 to 8 times its vol. of 
 air and explode by applying a flame. (Ask for instructions !) 
 
 How would you determine the molecular weight of this compound ? 
 
 (3) Make a eudiometric combustion of i vol. of CH 4 with 2 vols. of O 
 as described in Richter, p. 121. 
 
 (4) Ethane C a H 6 . (Richter, p. 153.) 
 
 Ethylene C 2 H 4 . Into a ^ litre flask put 5 grms. of alcohol and 30 
 grms. of H 2 SO 4 . Heat to 160 C. and add gradually a mixture of i part of 
 alcohol and 2 parts of H 2 SO 4 . Note the color, odor, taste and solubility of 
 the escaping gas. What is its most characteristic property ? 
 
 (5) Acetylene C 2 H 2 . Light a Bunsen burner at the base and turn it 
 
22 
 
 down, so that the flame is small. Acetylene can be recognized, among the 
 products of combustion, by its characteristic odor. 
 
 (6) CARBON AND THE HALOGENS. (Richter, p. 160.) 
 
 CARBON AND OXYGEN. 
 
 (7) Carbon dioxide CO 2 . 
 
 i. Preparation, Upon pieces of marble, contained in an evolution 
 flask, pour dilute HC1. Conduct the resulting gas through water and 
 through cone. H 2 SO 4 . It may be collected either by downward displace- 
 ment of the air, or over mercury. 2. Note color, taste and odor of this gas. 
 Is it soluble in water ? How does its weight compare with that of air ? 
 Does it burn or support combustion ? j. Conduct a current of CO 2 into a 
 solution of NaOH, evaporate the liquid, and test the residue for Na 2 CO 3 (?). 
 4. To different portions of Na 2 CO 3 solution, add solutions of MgSO 4 , BaCl 2 , 
 Pb(N0 3 ) 2 , ZnS0 4 (?). 
 
 (Study Richter, pp. 228-232.) 
 
 (8) Carbon monoxide CO. 
 
 Preparation. /. In a tube of hard glass heat zinc dust to faint redness, 
 while conducting a slow current of CO 2 over it. In what respect does the 
 product differ from CO 2 . 2. Pass steam over red-hot pieces of C. Result ? 
 j. Heat crystals of oxalic acid with cone. H 2 SO 4 in a flask, and wash the 
 product with NaOH solution. Write the reaction. Study the properties of 
 this gas. (Richter, p. 233). 
 
 (9) Carbon disulphideS 2 . 
 
 Perform some of the experiments indicated in Richter, p. 234. 
 
 (10) CARBON AND NITROGEN. 
 
 /. In a dry test tube heat a nitrogenous carbon compound with a small 
 piece of K. Cool and add water. KCN is formed and can be tested with 
 AgNO 8 . 2. Convert a portion of the KCN into KCNS by evaporating with 
 (NH 4 ) 2 S. Test with FeCl 8 . j. To a solution of FeSO 4 add potassium 
 ferrocyanide. What results? 4. What is the action of the ferrocyanide 
 upon solutions of ferric salts ? 
 
 (n) Study the nature of flame. Make the experiments described in 
 Richter, pp. 155-160. 
 
 SIUCON. Si. 
 
 (i) Preparation. Make an intimate mixture of i grm. magnesium 
 powder and 4 grms. of finely powdered quartz-sand. Heat this in a wide 
 lube of hard glass, to bright redness. It is best to use the blast lamp for 
 this purpose. That part of the tube, containing the mixture, should be 
 rotated in the flame. The residue, after a few minutes' heating, is allowed 
 to cool, and treated with water containing HC1. The product consists of 
 .amorphous silicon and undecomposed quartz. 2. Test the action of the 
 following reagents upon Si : sulphuric, nitric and hydrofluoric acids, potash 
 solution and a current of HC1 gas. 3. Fuse a portion of the amorphous 
 silicon with granulated zinc in a closed Hessian crucible. Heat the mass 
 for some time to the boiling point of Zn. Extract the residue with dilute 
 HC1 ; what remains? (Read Richter, p. 161.) 
 
23 
 
 SIWCON AND OXYGEN. 
 
 (2) Silicon dioxide (Silica, Quartz) SiO 2 . 
 
 7. Test its solubility in the various acids and alkalies. 2. Fuse a mix- 
 ture of i grm. of finely powdered quartz with 4 grms. of Na 2 CO 3 , in a 
 platinum crucible. Dissolve the product in water, j. To a portion of this 
 solution add HC1, and evaporate to complete dryness. Take up the residue 
 with water and filter off the insoluble portion. 4. To another portion of 
 the aqueous solution of the fusion add NH 4 C1. (?) 5. Make a bead of salt of 
 phosphorus ; bring a fragment of a silicate or of quartz into it, and heat in 
 the blow-pipe flame for a few moments (?) . 
 
 BORON. B. 
 
 (1) Preparation similar to that of Si. What are its properties ? Does 
 it unite directly with other elements ? Is it known in several allotropic 
 modifications ? What is the valency of this element ? 
 
 (Read Richter, p. 240 and 241.) 
 
 BORON AND OXYGEN. 
 
 (2) Boric acid BO 3 . 
 
 7. Dissolve borax iii 4 parts of boiling water, add HC1 to acid reaction, 
 and allow to cool. What crystallizes out of the solution ? Dry some of the 
 product by pressing it between filter paper. Test its solubility in water and 
 in alcohol. What do you observe on igniting the alcoholic solution ? 
 Moisten a piece of turmeric paper with an aqueous solution of boric acid, 
 and dry at a gentle heat. What happens? 
 
 Problems. (i) How much CO 2 results from the combustion of 12 grms. 
 of carbon? (2) How much CO 2 will an indefinite quantity of CaCO 3 give, 
 when acted upon by 4*666 grms. of muriatic acid, containing 30 per cent, of 
 pure HC1 ? (3) How many cubic decimeters of CO can be obtained from 
 90 grms. of oxalic acid ? (4) What amount of SiO 2 can be obtained from 2 
 grms. of Wollastonite (CaSiO 3 ) ? (5) What is the theoretical quantity of 
 boric acid obtainable from 15 grms. of borax (Na 2 B 4 O 7 -f- ioH 2 O) ? 
 
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