PROBLEMS AND QUESTIONS IN General Chemistry | ARRANGED FOR THE USES OF STUDENTS IN THE Chemical Laboratory OF THE UNIVERSITY OF ILLINOIS BY CLARENCE W. BALKE SECOND EDITION Published by the U. of I. Supply Store Champaign, Ill. 1911 Winiversity of iinois Library al Urbana-Champaign Oak Street ny ’ t We, — ie *._f. BlVMee : % INTERNATIONAL ATOMIC WEIGHTS, 1911. Symbol. Aluminium........ Al ADUMONY. .....- Sb EEO on otatw ais Ss A A TRETLICS po es eos As PRRR TEER ee. S08. x on Ba iS Tk A Bi OS B Bromine: ..5..... Br PPA WM oy ssc 30 Cd 0 ere Cs NAITYAS 5 os ao Ca BeeaTDON. 2 ss 0. Cc MOET sic ss ws Ce PTUOPING. ses. Cl ORPONIUM.....% . Cr DOANE .0.23 ek > os Co Columbium...... Cb Gper.. svc... Cu os Dysprosium..... Dy ag MERRURULE ceva pee. 6 « Er Ni PUTOpIUM ... 6... Ku = ee PiMOTING. . 0... KF = Gadolinium...... Gd = Gallium......... Ga = Germanium..... Ge PeUUCERIIN 5. cc ees Gl Eine fia oe unl es Au BEIT si 5.5s0-h 0 Beier... 3. %... Li > HeULeCIUM. =. 4... Lu ] Maznesium..... Mg i Manganese..... Mn J Mercury... .\<.. Hg Atomic weight 27.1 120.2 39.88 74.96 137.37 208.0 11.0 79.92 112.40 132.81 40.09 12.00 140.25 35.46 52.0 58.97 93.5 63.57 162.5 167.4 152.0 19.0 157.3 69.9 72.5 vet 197.2 3.99 1.008 114.8 126.92 193.1 55.85 82.92 139.0 207.10 6.94 174.0 24.32 54.93 200.0 ioe) Symbol. Molybdenum.... Mo Neodymium..... Nd INGOT AE orrak tas Ne INICKGL: Gites sat Ni Nitrogen. o.7.. 6. N— CSM ae en ate Os Gereen es As uae. Oz Palladium....... Pd Phosphorus...... jie Platinum .wi.%. . Pt Potassitim <2. 2 1 ae Praseodymium... Pr Radium. j24.%: Ra NOG te oes Rh Rubidium: .24..- Rb Ruthenium...... Ru SAMArLUMh. 2... Sa Seandiums. <3... Sc Selenium yi .05%.. < Se PLLICOM yc erste toes Si Siiveteens tas cde Ag SOOM ua. eis Na Strenuum tian at sr STi bONUh. an ete. a Sco Tanteium: «ic. Ta Tellurium....... Te AA DU Ue Cg tee Tb THeMMMs war or lh AS LQTBILTEL « sivceccterava Th POMHUM: ws feces Tm PATE Gt sa ae Sn PELEA TAI vais ch .a é hy AUINSSten Ss. se... W SEP OTN. GP hecs 28 U WETIAG PUI ot. oes V EPR TIVOLI ths cd So spied ae Ytterbium (Neoytterbium) Yb SY LED TUT soe cysts sts YY. VARI T at SNS ye Zn AITCORIMNY 3 aa. Zr Atomic weight 96.0 144.3 20.2 58.68 14.01 190.9 16.00 106.7 31.04 19552 39.10 140.6 226.4 102.9 85.45 101.7 150.4 44.1 79.2 28.3 107.88 23.00 87.63 32.07 181.0 Lhe 159.2 204.0 232.4 168.5 119.0 48.1 184.0 238.5 51.06 130.2 172.0 89.0 65.37 90.6 cece = Peee=4L p9¢c=Pa 3 uniuely UInLIoOyL, unipey T ae % g07=14 Uin~=4d. 0'F02=1L 0'0072=8H 2 L6T=1V yynusig peoy uniyTeyL |AImorop PIOx) 1 (NY )2'S6T=Id Ue6t=s1 6'061T=SO is PRT=M TRT=BL < cLT=4A i , is wani}eIq WInpH] UNIUIsCO uaissuny) wnyrjury, UINIGI9}} A OT 6 tot = = a 2 ox 62'0FT=90 O'6EL=2T). - se-veTS=Va| Te ekI=S9) 2 oeI=exX Uintie)| UnuBYue’y unlieg| wniseeD) uousx| 8 76° 9¢T=1 C LeT=3,1 2 02zT=4S 0'6TT=US SPIT=uUl ®71T=P0 QQ /OT=BV ourIpoy wunlIntaL jAuowmyj0y ULL uni puy UInIUIpeED IOATIG L (8V)L90T=Pd 6'2OI=UN LL TOT=94 sy n'9n—OW spR=a 9°06 =17, 0'6R=A caye—is| cpce—aM| 26°78=10| UInIpEl[eq wnIpoyYy wniusyny uInuspqA[OW) winiquinjoD| Wnluo0dIIZ WANA! won| wnipiqny| woId4éry 9 26°6L=10 =| /2"47=2S gg rL=sv [s'7l=9) 6'69=P4) “CQ=Uz re-ro—n on ae sulmoig UINIM3[IS dUSNSsSIV TWINIOVM1aL) | une ae - Sere s (1D)468S=9D 8O8S=IN Ssesc=eH £6 PS =UW (i76=16) 9N'TS=A TRP=LL TPp=og} 60'NP=FBO TAR=N| «886 =1V ; Wweqog TOXOIN uoI]| sSouRBUR| uIntMoIqD) WopeueA; WMIULTL) wurnrpusos TINIO[eD) ur, Issv110g uosIy 9FSE=ID LO 7h=S PO TS=d FRA=1S TLe=1V 26°$7—S8| 0'F7=BN|c 0C=9N ¢ suTIO[yO Inydjng snioydsoyd |FOONIS wmanUTany vy UINISOUSP WINnIpoS | FOIN . pat j aes pf Tari 0'61=4 on oT=O 10'FT=N Vat=O 0TT=a4 T6=) b6°9=!T| 66E=9H 2 eulion[y uds3AXO usBOI}IN wuoqiey) wo1og wnuUIon{y)| wIntyiT tania H 800° T=H I usso0IpAy BOs Hua *Ha & PHU C2 : oe ee L0274Y 204*%Y ack FO*Y £62 CO*Y O24 IIIA dnoin IIA dnory | [A dnoisy A dnoir) AJ dnois TIT dno J] dnoiy J dno1yH |dnoino01987| sa1iag SUNHWATH AHL AO WIEAVL OIGOINHd AHL TENSION OF AQUEOUS VAPOR IN MILLIMETERS. oe _ Temperature |Tension|| Temperature |Tension|| Temperature | Tension 33°C. 37.4 0°. 4.6 17°C. 14.4 1 4.9 18 15.4 34 39.6 2 5.3 19 16.4 35 41.9 3 BE. 20 17.4 40 55 0 4 6.1 21 18.5 45 71.5 5 6.5 22 19.7 50 92.2 6 7.0 23 20.9 55 117.8 7 7.5 24 22.9 60 149.9 8 8.0 25 93.5 65 187.5 9 8.6 26 | 95.0 70 933.8 10 9.2 27 26.5 15 289.3 11 9.8 28 28-4 80 355.5 12 10.5 29 29.8 85 433.8 13 11.2 30 31.6 90 526.0 14 11.9 31 33.4 95 634.0 15 12.7 32 354 100 760.0 16 13.6 | WEIGHT OF ONE LITER OF GAS AT 0° AND 760 MM. PRESSURE. Substance Formula Weight of 1 Liter. Acetylene CoH. 1.162 Ammonia NH, 0.762 Argon A 1.782 Arsine AsH, 3.485 Bromine Br, 7.143 Carbon dioxide | co, 1.965 Carbon monoxide CO b heat Chlorine Cols 3.167 Ethane C.H, 1.342 Ethylene CoH, 1,252 Fluorine i's L097 Hydrogen H, 0.0899 Hydrogen bromide HBr 3.616 Hydrogen chloride HCl 1.628 Hydrogen fluoride HF 0.894 Hydrogen iodide HI Oe § Hydrogen sulphide H.S 1.523 Methane CH, 0.716 Nitric oxide NO 1.342 N:trogen ; N., 1.254 Nitrogen dioxide NO, 2.056 Nitrous oxide N,O 1.969 Oxygen O, 1.429 Phosphine BE: 1.520 Silicon tetrafluoride SiF, 4.663 Sulvhur dioxide so, 2.861 Note :—Use 35.5 as the atomic weight of chlorine and the nearest whole number in the case of the other elements, use 0.09 gram as the weight of one liter of hydrogen, and consider all conditions standard unless otherwise stated. 1. A stream of oxygen was passed over 1.07 grams of heated magnesium and 1.78 grams of the oxide were ob- tained. Calculate the combining weight of the metal. 2.. The combining weight of chlorine is 35.5. With what weight of chlorine will 40 grams of magnesium com- bine? 3. Irom the following data calculate the combining weight of copper :— Weight of boat empty..02s5 ea 11.782 Weight of boat + copper........ 12.128 Weight of boat + copper oxide. ..12.215 4." A flask weighs 17.642 grams in air. Its weight full of water is 86.726 grams, and when filled with sul- phurie acid the w ea is 52.183 grams. Calculate the spe- cific gravity of the acid. If an error of one gram were mnade in the last weighing, what would be the per cent. error in the result? ». Two grams of sulphur were burned in oxygen giy- ing 4 grams of an oxide. Calculate the formula of the lat- Ler: 6. Four grams of a compound of copper and chlorine were found to contain 2.56 grams of copper. What is the formula of the compound? ¢. From their percentage compositions find the form- ulae of the following substances :— if Il. TE MWigae sh Rees te 72.41 Sodium.... 17.56 Water H,O 55.90 Oxygen.... 27.59 Chronium.. 39.69 Oxygen... 19.87 Oxygen.... 42.75 Sulphurs.9 eee Sodium... 14.28 8. Find the percentage composition of substances having the following formule: Zn SO,, P.O;, H.RO,. 9. What weight of sulphur will combine with 0.7 gram of mercury? 10. If 1 gram of sulphur and 5 grams of mercury are rubbed together in a mortar, a portion of which element re- mains uncombined and in what amount? 11. What weight of silver can be obtained from 40 erams of an ore having the formula Ag,AsS,? 12. Will 22 grams of mercuric oxide give more or less oxygen than 12 grams of potassium chlorate? 138. How much mercuric oxide is required for the preparation of 40 liters of oxygen? 14. What weight of potassium chlorate will be re- quired to give 20 grams of oxygen. 15. What weight of oxygen can be obtained from 1.2 grams of potassium chlorate? 16. What weight of mercury will result on the de- composition of 30 grams of mercuric oxide? 17. What weight of potassium chloride can be ob- tuined by the ignition of 4 grams of potassium chlorate? 18. When MnO, is ignited to a high temperature it gives oxygen and Mn,O,. What weight of oxygen can be obtained from 5 grams of manganese dioxide? 19. In the case of the two oxides of manganese, MnO, and Mn.O,, determine the weight of oxygen combined with one gram of manganese in each compound. What simple ‘atio do the two amounts of oxygen bear to each other? What law does this illustrate? 20. Two grams of iron were burned in oxygen, giv- ine 2.762 grams of an oxide. Find the formula of the latter. “NI 21. How many calories of heat are liberated in the combustion of 36 grams of carbon? When 3 grams of phosphorus are burned in oxygen 17,800 calories of heat are liberated. Calculate the heat of combustion of phosphorus. 23. The specific heat of lead is 0.031. How many cal- ories of heat are required to raise the temperature of 200 erams of lead from 18° to 42°? 24. Jf 100 grams of granulated zinc having a specific heat of 0.093 are poured into 100 ce. of water at 20° and the temperature of the mixture is 26°, what was the orig- inal temperature of the zinc? 25. 274 cc. of gas measured at 0° would have what volume at 37°, the pressure remaining constant? 26. Reduce 100 ce. of gas at 19° to 59°, pressure re- maining constant. 27. Reduce 55 cc. of gas at 37° to —T7°, pressure re- maining constant. 28. Reduce 640 cc. of gas from 760 mm. to 700 mm., the temperature remaining constant. 29. Reduce 250 ce. of gas at 300 mm. to 1800 mm., the temperature remaining constant. 30. Reduce 140 ce. of gas at 21° and 200 mm. to 42° and 300 mm. 31. Reduce 600 ce. of gas at —20° and 400 mm. to —10° and 200 mm. 32. Reduce 200 ce. ofdry gas at 20° and 760 mm. to 0° and 760 mm. 33. Reduce 300 ce. of gas at 17° and 760 mm. to 45° and 760 mm., the gas being completely saturated with wa- ter yapor under both conditions. 8 34. A sample of gas at 20° and 730 mm. is maintain- ed at a constant volume, but the temperature is raised to deo. ind the pressure. .385. What volume will 400 cc. of dry gas at 20° and 740 mm. occupy at 30° and 800 mm. if completely satur- ated with water vapor? 36. What will be the weight of 20 liters of oxygen at 13° and 420 mm. if the gas is one-half saturated with water vapor? 37. What volume of dry oxygen at 16° and 560 mm. will be required to combine with 50 grams of phosphorus? 38. What is the weight of one liter of air at 25° and 640 mm.? 39. ° L- 66. How 1 tained in 2 kilogra4 (8. What volume of hydrogen chloride will result from burning 35.45 grams of chlorine in hydrogen? 12 : p> é° 79. Whét weight and volume of hydrogen chloride can be prepared from 350 grams of sodium chloride? 80. What weight of hydrogen chloride is contained in 650 cc. of a tenth normal solution? 2 81. What volume of hydrogen chloride 194.540. passed into 99 grams of water in of tne make vet 5 a erams of a 1 per cent. solution? o¢tan rebar 13 ie! £ 2. A solution of hydrogen chloride having 13.65 -eravity of 1.2 contains 39.11 per cent. by weight of the gas. What volume of the dry gas at 10° and 700 mm. will be required to make 7 liters of such a solution? £ 83. What volume of a 10 per cent. solution (sp. gr. C9 wick wah of ey =1.05) of hydrochloric acid will be required to dissolve 6 - erams of magnesium? 84. Calculate the weight of one liter of a gas having the formula C,H... 85. The weight of one liter of a gas is 1.97 grams. What is the molecular weight of the substance? 8&6. Calculate the weight of one liter of a gas having the formula AsH,. 87. What is the weight of 3 liters of bromine vapor at 69° and 400 mm.? 88. The molecular weight of a substance is 271. What is the weigth of 1. liter of the gas at 275° and 760 mm. ? 89. The chloride of a metal contains 25.26 per cent. of the metal and 74.74 per cent. of chlorine. The specific heat of the metal is 0.250. What is its valence and atomic weight? 90. . The molecular weight of a substance is 78. What is the weight of one liter, and what is its density referred to air and to hydrogen? 13 ® 91. The density of a substance referred to air is 0.968. An analysis of 3.26 grams gave 2.79 grams of car- bon and 0.47 gram of hydrogen. What is the formula of the substance? *92.. A compound contains one gram of hydrogen for every twelve grams of carbon and has a molecular weight of 78. What is its formula? 93. “PHeNPecitfic heat of a metal is 0.112. 1.625 grams of its chloride contains 0.560 gram of the metal. What is the atomic weight of the metal and what is the formula of the chloride? 94. If the atomic weight of oxygen was placed at 75, what would be the G. M. V.?) What would be the atomic weight of bromine? | 95. What weight of bromine would result from the action of sulphuric acid and manganese dioxide on 8.3 erams of potassium bromide? If the bromine were all con- densed and collected as a liquid what volume would it occupy? 96. What volume of dry bromine calculated as va- por under standard conditions will be liberated from a so- lution of potassium bromide by 23 grams of chlorine? 97. What volume of vapor at 200° and 760 mm. will be produced by 7 cc. of liquid bromine? 98. What weight of phosphorus acid is produced when 140 grams of hydrogen bromide is prepared by the action of bromine on moist phosphorus? 99. What weight of water will react with 11 grams of phosphorus triiodide? What volume of hydrogen io- dide will result from such action? 100. What weight and volume of hydrogen iodide will be required to make 75 grams of the constant boiling solution ? 14 101.. Calculate the percentage of fluorine in the min- erals fluorite and cryvolite. 102. How much sulphuric acid will be required to decompose 50 grams of fluorite? What volume of gas at 43° and- 750 mm. will result? 1038. What volume of chlorine will react with 15 grams of potassinin hydroxide in solution? 104. When chlorine is passed into a dilute solution of potassium hydroxide, what volume of the gas will be used in the preparation of 40 grams of potassium hypo- chlorite? L105.) What amount of potassium hypochlorite will be decomposed by 20 grams of a 30 per cent. hydrochloric acid solution? 2.106. What volume of oxygen will result through the decomposition of 30 grams of hypochlorous acid? 107. What weight of sodium hydroxide will be neu- tralized by 20 grams of hypochlorous acid? 108. In the preparation of potassium hypobromite, what volume of liquid bromine should be added to a solu- tion containing 100 grains of potassium hydroxide? 109. What volume as ozone would 9 grams of oxy- ven occupy ? . 110. What amount of potassium iodide will be oxi- dized by 3 grams of ozone? 111. What volume of ozone will 50 cc. of water dis- solve froin a gas mixture containing 2.7 per cent. of ozone? 112. What amount of sodium peroxide and hydro- chlorie acid must be used to produce 480 grams of a 3 per cent. solution of hydrogen peroxide? 113. What volume of carbon dioxide will be ab- sorbed if passed into water in which 25 grams of barium peroxide is suspended? 15 * 4114. What relative volume of oxygen can be obtain- ed from a 8 per cent. solution of hydrogen peroxide? 115. Define unit molecular concentration. What is the molecular concentration of a solution containing 70 erams of sodium chloride in 6 liters. 116. What is the molecular concentration of the aqueous vapor above water at 14° and at 35°? 117. A gas mixture contains 25 per cent. of oxygen and 75 per cent. of nitrogen by volume and the mixture is under. a pressure of 9 atmospheres. Calculate the mole- cular concentration of each of the gases, 118. What is the molecular concentration of oxygen if nnder a pressure of 890 mm.? 119. Under what conditicns will any gas have unit molecular concentration ? 120. What weight of potassium permanganate will be reduced by 7 grams of hydrogen peroxide? 121. What amount of hydrogen peroxide will be re- quired to reduce 2 grams of potassium dichromate? 122. What weight of sodium hydroxide would be neutralized by 100 ce. of a solution of sulphuric acid, p7 e) density 1.20 and containing 27.3 per cent. of the pure acid? 128. What weight of crystallized sodium carbonate will be neutralized by 400 ce. of a normal solution of hy- drochloric acid? What volume of gas will be liberated? 124. What weight of silver will be deposited by a current of electricity which liberates 200 cc. of hydrogen? 125. What weight of mercury will be thrown out of a solution of mercurous nitrate by 2 grams of copper? 126. What weight of lead will be thrown out of. a so- lution by 9 erams of zinc? 16 127. What weight of sodium carbonate will be re- quired to neutralize 40 grams of sulphuric acid? 128. Tow much aluminum will be dissolved by 90 ce. of a solution of hydrochloric acid, one ee. of which will neutralize 1.31 cc. of a normal sodium hydroxide solution? 129. What weight of hydrogen sulphide would re- sult from the action of sulphuric acid on 18 grams of zine sulphide? 130. What weieht of hydriodic acid will be oxidized — to iodine in producing 7 grams of hydrogen sulphide? 131. What volume of hydrogen sulphide will result from the action of hydrochloric acid on 200 grams of fer- rous sulphide? 132. What volume of oxygen will be used in the com- bustion of 4 grams of sulphur? What will be the volume of sulphur dioxide formed? 133. What weight of stibnite, Sb.S., must be treated with hydrochloric acid to produce 63 ce. of hydrogen sul- plide at —8° and 740 min.? 134. What amount of potassium dichromate will be reduced by 92 grams of hydrogen sulphide? 135. What volume of hydrogen sulphide will be re- quired to precipitate all the lead from a solution contain- ing 380 erams of lead nitarate? 136. What volume of hydrogen sulphide will dis- solve in 200 ce. of water if the gas is under a pressure of 960 mm.? 137. What volume of oxygen at 20° and 745 mm. will be used up in the combustion of 500 grams of pyrite? 18s. What weight of sulphuric acid will be required to decompose 50 grams of sodium sulphite? . £7 139. How much copper must be heated with sul- phurie acid to produce 96 ce. of sulphur dioxide? 140. With what volume of oxygen will 90 liters of | sulphur dioxide combine in the preparation of sulphur tri- oxide by the contact process? 141. How much Glauber’s salt, Na,SO,, 10H, O, can be prepared from 900 grams of sodium chloride? 142, How much sodium thiosulphate can be pre- pared from 100 grams of sodium sulphite? 143. What volume .of nitrogen at 17° and 765 mm. (measured over water) can be obtained from 20 grams of ammonium nitrite? 144. How much ammonium sulphate must be used in the preparation of 40 liters of dry ammonia at —8° and 860 mm.? 145. Tfow much nitric acid will react with 1000 ce. of a solution containing 15 per cent. of ammonia and hay- ing a specific gravity of 0.942? 146. How much nitric acid can be obtained from 60 erams of magnesium nitrate? 147. With what weight of ferrous chloride will 2 erams of nitric acid react? 148. What volume of nitric oxide will be produced when 50 grams of copper are disolved in nitric acid, as- suming that no other gas is formed? 149. -With what volume of oxygen will 8 liters of nitric oxide unite in forming the dioxide? 150. How much ammonium nitrate will result when very dilute nitric acid reacts with 10 grams of zinc? 151. Calculate the percentage of phosphorus in the mineral apatite, Ca,F(PO,) ». 18 152. How much potassium hydroxide and how much phosphorus are required to make 1.2 grams of phosphine by the interaction of the two substances? What volume would this amount of phosphine occupy under standard conditions? 153. What is the relative percentage of phosphorus in magnesium ammonium phosphate and magnesium pyro- phosphate? 154. With what volume of oxygen at 32° and 742 mim. will 4 grams of carbon combine to form carbon di- oxide? 155. What volume of air is needed for the combus- tion of 600 pounds of carbon? 156. What weight of marble must be treated with an acid to produce 15 liters of carbon dioxide at 4° and 600 mm. if saturated with water vapor? 157. The specific gravity of liquid carbon dioxide at 0° is 0.95. What volume would 9 ce. of this liquid occupy as a gas at —30° and 3 atmospheres pressure? 158. What volume of carbon dioxide will dissolve in 700 ce. of water if the gas is supplied under a pressure of 2.3 atmospheres? 159. What volume of carbon dioxide and what vol- ume of water vapor, both measured at 110° and 760 mm., will result from the ignition of 45 grams of sodium bicar- bonate? ; 160. What are the relative volumes of carbon diox- ide and carbon monoxide resulting from the ignition of oxalic acid? 161. What volume of methane will result from the ignition of 20 grams of sodium acetate with sodium hy- droxide? » 162. What volume of ethylene can be produced from 20 grams of alcohol? 19 LANL 3 77681119 01120 163. How much calcium carbide must be used to pro- duce 45 liters of acetylene if the former is only 67 per cent. pure? — 164.What volume of carbon dipside will escape dur- ing the fermentation of 50 grams of cane-sugar? | 165. Compare the volumes of oxygen required for the complete combustion of 10 grams each of methane, ethylene, and acetylene. 166. What volume of air will eunicl the oxygen re- quired for the combustion of 60 grams of acetylene? 167. What weight of glycerine is produced during the saponification of 600 grams tripalmitin? 168. What volume of oxygen is used up in convert- ing 70 grams of alcohol into acetic acid? 169. What weight of silicon dioxide can be reduced by 40 grams of magnesium? ? 170. What volume of silicon hydride can be pre- pared from 20 grams of magnesium silicide? 171. What weight of hydrofluosilicic acid can be pre- pared from 10 liters of silicon tetrafluoride? 172. What weight of baruim chloride will react with 4 grams of hydrofluosilicie acid? 173. Calculate the percentage composition of the mineral colemanite. 174. What weight of boron is contained in 45 liters — of boron trifluoride? | 175. What weight of boric acid can be prepared from 60 grams of crystalized borax? 176. If gunpowder explodes according to the reaction 2KNO,+8C-+S =—K,S+-38C0,--N,, calculate what volume of gas would result from the igni- tion of one pound of the material. : 177. How much sodium carbonate can be made by the LeBlane process from 6 tons of sodium chloride and 20 tons of coal? 20