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Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 Chapter 4 4-1 (a) The millimole is an amount of a chemical species, such as an atom, an ion, a molecule or an electron. A millimole contains millimole particles1002.6 millimole mole10 mole particles1002.6 20323 ×=∗× − (b) The molar mass is the mass in grams of one mole of a chemical species. (c) The millimolar mass is the mass in grams of one millimole of a chemical species. (d) Parts per million, cppm, is a term expressing the concentration of very dilute solutions. Thus, cppm ppm10 solution of mass solute of mass 6×= The units of mass in the numerator and the denominator must be the same. 4-2 The species molarity of a solution expresses the equilibrium concentration of a chemical species in terms of moles per liter. The analytical molarity of a solution gives the total number of moles of a solute in one liter. The species molarity takes into account chemical reactions that occur in solution. The analytical molarity specifies how the solution was prepared, but does not account for any subsequent reactions. 4-3 33 33 m10 cm100 m mL cm1 L1 mL1000 1L −= ××= 3333 m10 mole1 m10 L L mole1M1 −− =×= Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 4-4 (a) kHz 320 Hz1000 kHzHz102.3 5 =×× (b) ng 6.45 g ng10g1056.4 9 8 =×× − (c) mmol 843 mol10 mmol mol1043.8 3 5 = µ ×µ× (d) Ms5.6 s10 Ms s105.6 6 6 =×× (e) m 6.89 nm10 m nm1096.8 3 4 µ=µ×× (f) kg 72 g1000 kgg000,72 =× 4-5 + + ++ ×= × ××× Na1098.5 Namol Na1002.6 PONamol Namol3 g94.163 PONamol1PONag43.5 22 23 43 43 43 4-6 + + ++ ×= × ×× K1022.1 Kmol K1002.6 POKmol Kmol3POKmol76.6 25 23 43 43 4-7 (a) 32 32 32 32 OBmol0712.0OBg62.69 OBmolOBg96.4 =× (b) O10HOBNamol1073.8 381.37g O10HOBNamol mg1000 gOH10OBNamg333 2742 4 2742 2742 ⋅×= ⋅ ×ו − (c) 43 43 43 43 OMnmol0382.0OMng81.228 OMnmolOMng75.8 =× (d) 423 42 42 42 OCaCmol1031.1OCaCg128.10 OCaCmol mg1000 gOCaCmg2.167 −×=×× Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 4-8 (a) 52 52 52 52 OPmmol40.0 mol mmol1000 OPg94.141 OPmol mg1000 gOPmg57 =××× (b) 2 2 2 2 COmmol6.293 mol mmol1000 COg01.44 COmolCOg92.12 =×× (c) 3 3 3 3 NaHCOmmol476 mol mmol1000 NaHCOg01.84 NaHCOmolNaHCOg0.40 =×× (d) 44 44 44 44 POMgNHmmol2.6 mol mmol1000 POMgNHg137.32 POMgNHmol mg1000 gPOMgNHmg850 = ××× 4-9 (a) 4 4 3 4 3 KMnOmmol50.6 L00.2 mol mmol1000 L KMnOmol1025.3M KMnO1025.3 = ×× × ≡× − − (b) KSCNmmol6.41 mL750 mL1000 L mol mmol1000 L KSCNmol0555.0 M KSCN0555.0 = ×××≡ (c) 4 3 4 44 4 CuSOmmol1047.8mL250 mL1000 L mol mmol1000 CuSOg61.159 CuSOmol mg1000 g L CuSOmg41.5CuSO ppm 41.5 −×=×× ×××≡ (d) KClmmol6.1165L50.3 mol mmol1000 L KClmol333.0 M KCl333.0 =××≡ Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 4-10 (a) 4 4 4 HClOmmol0.56 mL175 mL1000 L mol mmol1000 L HClOmol320.0HClOM320.0 = ×××≡ (b) 42 42 3 42 3 CrOKmmol121 L0.15 mol mmol1000 L CrOKmol1005.8CrOKM1005.8 = ×× × ≡× − − (c) 3 3 33 3 AgNOmmol199.0L00.5 mol mmol1000 AgNOg87.169 AgNOmol mg1000 g L AgNOmg75.6AgNOppm75.6 = ××××≡ (d) KOHmmol0.17 mL851 mL1000 L mol mmol1000 L KOHmol0200.0KOHM0200.0 = ×××≡ 4-11 (a) 34 3 3 3 HNOmg1090.4g mg1000 HNOmol HNOg01.63HNOmol777.0 ×=×× (b) MgOmg10015.2 g mg1000 MgOmol MgOg40.30 mmol1000 molMgOmmol500 4×=××× (c) 346 34 34 34 NONHmg1080.1g mg1000 NONHmol NONHg04.80NONHmol5.22 ×=×× (d) 6324 6 6324 6324 6324 )NO(Ce)NH(mg1037.2 g mg1000 )NO(Ce)NH(mol )NO(Ce)NH(g23.548)NO(Ce)NH(mol32.4 ×= ×× Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 4-12 (a) KBrg840 KBrmol KBrg0.119KBrmol1.7 =× (b) PbOg49.4 PbOmol PbOg20.223 mmol1000 molPbOmmol1.20 =×× (c) 4 4 4 4 MgSOg452MgSOmol MgSOg37.120MgSOmol76.3 =× (d) OH6)SO()NH(Feg8.3 OH6)SO()NH(Femol OH6)SO()NH(Feg23.392 mmol1000 molOH6)SO()NH(Femmol6.9 22424 22424 22424 22424 ⋅= ⋅ ⋅ ××⋅ 4-13 (a) sucrosemg1022.2 mL0.26 g mg1000 sucrosemol sucroseg342 mL1000 L L sucrosemol250.0 sucroseM250.0 3×= ××××≡ (b) 22 22 2222 3 22 3 OHmg8.472 L92.2 g mg1000 OHmol OHg02.34 L OHmol1076.4OHM1076.4 = ××× × ≡× − − (c) 23 23 23 )NO(Pbmg25.3mL656 mL1000 L L )NO(Pbmg96.4)NO(Pbppm96.4 =××≡ (d) 3 33 3 KNOmg2.42 mL75.6 mL1000 L g mg1000 mol KNOg10.101 L KNOmol0619.0KNOM0619.0 = ××××≡ Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 4-14 (a) 22 22 2222 22 OHg51.2 mL450 OHmol OHg34.02 mL1000 L L OHmol0.164OHM164.0 = ×××≡ (b) acidbenzoicg1088.2mL0.27 acidbenzoicmol acidbenzoicg122 mL1000 L L acidbenzoicmol1075.8 acidbenzoicM1075.8 3 4 4 − − − ×= ××× × ≡× (c) 222 SnClg0760.0L50.3 mg1000 g L SnClmg7.21SnClppm7.21 =××≡ (d) 3 3 33 3 KBrOg0453.0 mL7.21 KBrOmol KBrOg167 mL1000 L L KBrOmol0125.0KBrOM0125.0 = ×××≡ 4-15 (a) 077.1)2(923.0 )10log()38.8log( )M1038.8log()M0838.0log()M0503.0M0335.0log(pNa 2 2 =−−−= −−= ×−=−=+−= − − 475.1)2(525.0 )10log()35.3log( )M1035.3log()M0335.0log(pCl 2 2 =−−−= −−= ×−=−= − − 298.1)2(702.0 )10log()03.5log( )M1003.5log()M0503.0log(pOH 2 2 =−−−= −−= ×−=−= − − Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 (b) 116.2)3(884.0 )10log()65.7log( )M1065.7log(pBa 3 3 =−−−= −−= ×−= − − 188.0)M54.1log(pMn −=−= 490.0)M08.3log())M54.12(M1065.7log(pCl 3 −=−=×+×−= − (c) 222.0)1(778.0 )10log()00.6log( )M1000.6log()M600.0log(pH 1 1 =−−−= −−= ×−=−= − − 096.0)1(904.0 )10log()02.8log( )M1002.8log()M802.0log())M101.02(M600.0log(pCl 1 1 =−−= −−= ×−=−=×+−= − − 996.0)1(00432.0 )10log()01.1log( )M1001.1log()M101.0log(pZn 1 1 =−−−= −−= ×−=−= − − (d) 320.1)2(679.0 )10log()78.4log( )M1078.4log(pCu 2 2 =−−−= −−= ×−= − − 983.0)1(0170.0 )10log()04.1log( )M1004.1log()M104.0log(pZn 1 1 =−−−= −−= ×−=−= − − 517.0)1(483.0 )10log()04.3log( )M1004.3log()M304.0log())M104.02()M0478.02log((pNO 1 1 3 =−−−= −−= ×−=−=×+×−= − − Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 (e) 836.5)6(164.0 )10log()46.1log( )M1046.1log()M1012.4))M1062.2(4log((pK 6 677 =−−−= −−= ×−=×+××−= − −−− 385.6)7(615.0 )10log()12.4log( )M1012.4log(pOH 7 7 =−−−= −−= ×−= − − 582.6)7(418.0 )10log()62.2log( )M1062.2log()CN(pFe 7 7 6 =−−−= −−= ×−= − − (f) 171.3)4(829.0 )10log()75.6log( )M1075.6log(pH 4 4 =−−−= −−= ×−= − −+ 475.3)4(525.0 )10log()35.3log( )M1035.3log(pBa 4 4 =−−−= −−= ×−= − − 873.2)3(127.0 )10log()34.1log( )M1034.1log()M1075.6)M1035.3(2log(pClO 3 344 4 =−−−= −−= ×−=×+××−= − −−− 4-16 (a) M107.1)5(antilog)240.0(antilog]OH[ 53 −+ ×=−×= as in part (a) (b) M106.2]OH[ 53 −+×= (c) M30.0]OH[ 3 =+ Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 (d) M104.2]OH[ 143 −+ ×= (e) M108.4]OH[ 83 −+ ×= (f) M107.1]OH[ 63 −+ ×= (g) M04.2]OH[ 3 =+ (h) M3.3]OH[ 3 =+ 4-17 (a) 699.1)2(301.0 )10log()00.2log()M0200.0log(pBrpNa 2 =−−−= −−=−== −− pH = pOH = - log(1.0×10-7M) = 7.00 (b) 000.2)2(000.0 )10log()00.1log()M0100.0log(pBa 2 =−−= −−=−= − 699.1)2(301.0 )10log()00.2log()M0100.02log(pBr 2 =−−−= −−=×−= − pH = pOH = - log(1.0×10-7M) = 7.00 (c) 46.2)3(54.0 )10log()5.3log()M105.3log(pBa 33 =−−−= −−=×−= −− 15.2)3(84.0 )10log()0.7log()M100.7log()M105.3(2log(pOH 333 =−−−= −−=×−=××−= −−− pH = 14.00 – pOH = (14.00 – 2.15) = 11.85 Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 (d) 40.1)2(60.0 )10log()0.4log()M100.4log()M040.0log(pH 22 =−−−= −−=×−=−= −− 70.1)2(30.0 )10log()0.2log()M100.2log()M020.0log(pNa 22 =−−−= −−=×−=−= −− 22.1)2(78.0 )10log()0.6log( )M100.6log()M060.0log()M020.0M040.0log(pCl 2 2 =−−−= −−= ×−=−=+−= − − pOH = 14.00 – 1.40 = 12.60 (e) 17.2)3(83.0 )10log()7.6log()M107.6log(pCa 33 =−−−= −−=×= −− 12.2)3(88.0 )10log()6.7log()M106.7log(pBa 33 =−−−= −−=×−= −− 54.1)2(46.0 )10log()9.2log( )M109.2log()))M106.7(2())M107.6(2log((pCl 2 233 =−−−= −−= ×−=××+××−= − −−− pH = pOH = - log(1.0×10-7M) = 7.00 (f) 32.7)8(68.0 )10log()8.4log()M108.4log(pZn 88 =−−−= −−=×−= −− 25.6)7(75.0 )10log()6.5log()M106.5log(pCd 77 =−−−= −−=×−= −− Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 92.5)6(79.0 )10log()2.1log( )M102.1log()))M106.5(2())M108.4(2log((pNO 6 678 3 =−−−= −−= ×−=××+××−= − −−− pH = pOH = - log(1.0×10-7M) = 7.00 4-18 (a) M1014.2)10(antilog)33.0(antilog]OH[ 103 −+ ×=−×= as in part (a), (b) M733.0]OH[ =− (c) M92.0]Br[ =− (d) M105.4]Ca[ 132 −+ ×= (e) [Li+] = 1.66 M (f) M107.1]NO[ 83 −− ×= (g) M99.0]Mn[ 2 =+ (h) [Cl-] = 0.0955 M 4-19 (a) + + + =××××× NaM0479.0 g99.22 Namol L mL1000 mL g02.1 ppm10 1Nappm1008.1 6 3 − − − − ×=×××× 2 4 3 3 4 6 2 4 SOM1087.2g96.06 SOmol L mL1000 mL g1.02 ppm10 1SOppm270 (b) 320.1)2(680.0 )10log()79.4log()M1079.4log(pNa 22 =−−−= −−=×−= −− Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 543.2)3(458.0 )10log()87.2log()M1087.2log(pSO 334 =−−−= −−=×−= −− 4-20 (a) +− ++ ×=××× KM106.4 g10.39 Kmol mg1000 g L mL1000 mL100 Kmg18 3 − −− =××× ClM103.0 g45.35 Clmol mg1000 g L mL1000 mL100 Clmg365 (b) 34.2)3(66.0 )10log()6.4log()M106.4log(pK 33 =−−−= −−=×−= −− pCl = –log(1.03×10-1M) = –log(1.03)–log(10-1) = –0.0133–(–1) = 0.987 4-21 (a) OH6MgClKClM01037.0 g85.277 OH6MgClKClmol L00.2 OH6MgClKClg76.5 22 2222 ⋅⋅= ⋅⋅ × ⋅⋅ (b) + + = ⋅⋅ ×⋅⋅ 2 22 2 22 MgM01037.0OH6MgClKClmol MgmolOH6MgClKClM01037.0 (c) − − = ⋅⋅ ×⋅⋅ ClM0311.0 OH6MgClKClmol Clmol3OH6MgClKClM01037.0 22 22 (d) (w/v)%288.0%100 mL1000 L L00.2 OH6MgClKClg76.5 22 =×× ⋅⋅ Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 (e) − − − =×××≡ Clmmol777.0mL25.0 mol mmol1000 mL1000 L L Clmol0.0311ClM0311.0 (f) + + ++ ≡= ×× ⋅⋅ ×⋅⋅ Kppm405 L mg405 g mg1000 Kmol Kg10.39 OH6MgClKClmol1 Kmol1OH6MgClKClM01037.0 22 22 (g) 984.1)2(0170.0)10log()04.1log()M1004.1log(pMg 22 =−−−=−−=×−= −− (h) 507.1)2(494.0)10log()12.3log()M1012.3log(pCl 22 =−−−=−−=×−= −− 4-22 (a) 63 3636363 )CN(FeKM1074.4 g2.329 )CN(FeKmol L775 )CN(FeKg1210 mL775 )CN(FeKmg1210 −×=×≡ (b) + + − =×× KM0142.0)CN(FeKmol Kmol3)CN(FeKM1074.4 63 63 3 (c) −− − − ×=×× 3 6 3 63 3 6 63 3 )CN(FeM1074.4)CN(FeKmol )CN(Femol)CN(FeKM1074.4 (d) (w/v)%156.0%100 mg1000 g mL775 )CN(FemgK1210 63 =×× (e) + + ++− +− = ××× × ≡× Kmmol710.0 mL50.0 Kmol mmolK1000 mL1000 L L Kmol101.42KM1042.1 2 2 Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 (f) −− − − − − − ×≡=×× × × ≡× 3 6 33 63 6 3 6 63 3 663 3 63 3 Fe(CN)ppm1000.1Fe(CN) L mg1000 g mg1000 Fe(CN)mol Fe(CN)g211.95 Fe(CN)Kmol Fe(CN)mol L Fe(CN)Kmol104.74Fe(CN)KM1074.4 (g) 848.1)2(152.0)10log()42.1log()M1042.1log(pK 22 =−−−=−−=×−= −− (h) 324.2)3(676.0)10log()74.4log()M1074.4log()CN(pFe 3336 =−−−=−−=×−= −−− 4-23 (a) 33 3333 33 )NO(FeM281.0 g86.241 )NO(Femol L mL1000 mL g059.1 100 1 solutiong )NO(Feg42.6)NO(Fe%42.6 = ××××≡ (b) − − =×≡ 3 33 333 33 NOM844.0)NO(Femol NOmol3 L )NO(Femol281.0)NO(FeM281.0 (c) L )NO(Feg0.68 mol )NO(Feg86.241 L )NO(Femol281.0)NO(FeM281.0 33333333 =×≡ 4-24 (a) 2 22 2 NiClM11.1g61.129 NiClmol L mL1000 mL g149.1 100 1 solutiong NiClg5.12NiCl%5.12 =××××≡ (b) − − =×≡ ClM22.2 NiClmol Clmol2 L NiClmol11.1NiClM11.1 2 2 2 (c) 2223 NiClg144L mol NiClg61.129 L NiClmol11.1NiCl11.1 =××≡ Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 4-25 (a) OHHCg8.23solnmL500 100 1 solnmL OHHCg75.4OHHC)v/w(%75.4 525252 =××≡ Weigh 23.8 g ethanol and add enough water to give a final volume of 500 mL. (b) waterg2.476OHHCg8.23solng500waterg watergOHHCg23.8solng500 OHHCg8.23solng500 100 1 solng OHHCg75.4OHHC)w/w(%75.4 52 52 52 52 52 =−= += =××≡ x x Mix 23.8 g ethanol with 476.2 g water. (c) OHHCmL8.23solnmL500 100 1 solnmL OHHCmL75.4OHHC)v/v(%75.4 525252 =××≡ Dilute 23.8 mL ethanol with enough water to give a final volume of 500 mL. 4-26 (a) 383 383 383 OHCg525solnL50.2L mL1000 100 1 solnmL OHCg0.21OHC)v/w(%0.21 =×××≡ Weigh 525 g glycerol and add enough water to give a final volume of 2.50 L. (b) waterkg98.1OHCkg525.0solnkg50.2waterkg waterkgOHCgk0.525solnkg50.2 OHCg525solnkg50.2 kg g1000 100 1 solng OHCg0.21OHC)w/w(%0.21 383 383 383 383 383 =−= += =×××≡ x x Mix 525 g glycerol with 1.98 kg water. Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 (c) 383 383 383 OHCmL525solnL50.2L mL1000 100 1 solnmL OHCmL0.21OHC)v/v(%0.21 =×××≡ Dilute 525 mL glycerol with enough water to give a final volume of 2.50 L. 4-27 L300.0 POHmol0.15 LPOHmol50.4requiredPOH)w/w(%86volume L POHmol0.15 g0.98 POHmol L mL1000 mL waterg waterg reagentg71.1 100 1 reagentg POHg86POH)w/w(%86 POHmol50.4mL750 mL1000 L L POHmol00.6POHM00.6 43 4343 43 4343 43 43 43 43 =×= = ×××××≡ =××≡ Dilute 300 mL of the concentrated reagent to 750 mL using water. 4-28 L170.0 HNOmol9.15 LHNOmol70.2requiredHNO%5.70volume L HNOmol9.15 g0.63 HNOmol L mL1000 mL waterg waterg reagentg42.1 100 1 reagentg HNOg5.70HNO)w/w(%5.70 HNOmol70.2mL900 mL1000 L L HNOmol00.3HNOM00.3 3 33 3 33 3 3 3 3 =×= = ×××××≡ =××≡ Dilute 170 mL of the concentrated reagent to 900 mL using water. 4-29 (a) 3 33 3 AgNOg37.6 mL500 mL1000 L mol AgNOg87.169 L AgNOmol0750.0AgNOM0750.0 = ×××≡ Dissolve 6.37 g AgNO3 in enough water to give a final volume of 500 mL. Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 (b) HClL0475.0 HClmol00.6LHClmol285.0 HClmol285.0L1 L HClmol285.0HClM285.0 =× =×≡ Take 47.5 mL of the 6.00 M HCl and dilute to 1.00 L using water. (c) 64 64642 2 )CN(FeKg98.2 mol )CN(FeKg43.368 Kmol4 )CN(FeKmolKmol1024.3 Kmol1024.3mL400 mL1000 L L Kmol0810.0KM0810.0 =××× ×=××≡ + +− +− + + Dissolve 2.98 g K4Fe(CN)6 in enough water to give a final volume of 400 mL. (d) L216.0 BaClmol400.0 L g23.208 BaClmolBaClg0.18 BaClg0.18mL600 100 1 solnmL BaClg00.3BaCl)v/w(%00.3 2 2 2 2 2 2 =×× =××≡ Take 216 mL of the 0.400 M BaCl2 solution and dilute to 600 mL using water. (e) L0203.0 HClOmol8.11 LHClOmol240.0requiredHClO)w/w(%71volume L HClOmol8.11 g46.100 HClOmol L mL1000 mL waterg waterg reagentg67.1 100 1 reagentg HClOg71HClO)w/w(%71 HClOmol240.0L00.2 L HClOmol120.0HClOM120.0 4 44 4 44 4 4 4 4 =×= = ×××××≡ =×≡ Take 20.3 mL of the concentrated reagent and dilute to a final volume of 2.00 L using water. Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 (f) 42 4242 SONag67.1 mol SONag04.142 Namol2 SONamolNamol02348.0 Namol02348.0 g99.22 Namol mg1000 gNamg540 Namg540L00.9 solnL Namg60Nappm60 =×× =×× =×≡ + + + + + + + + Dissolve 1.67 g Na2SO4 in enough water to give a final volume of 9.00 L. 4-30 (a) 4 44 4 KMnOg5.39 mol KMnOg03.158L00.5 L KMnOmol0500.0KMnOM0500.0 =××≡ Dissolve 39.5 g KMnO4 in enough water to give a final volume of 5.00 L. (b) reagentL125.0 reagentmol00.8 LHClOmol00.1 HClOmol00.1L00.4 L HClOmol250.0HClOM250.0 4 4 4 4 =× =×≡ Take 125 mL of the 8.00 M reagent and dilute a final of volume of 4.00 L using water. (c) 2 222 MgIg39.1 mol MgIg11.278 Imol2 MgImolImol1000.1 Imol0100.0mL400 mL1000 L L Imol0250.0IM0250.0 =××× =××≡ − −− − − − Dissolve 1.39 g MgI2 in enough water to give a final volume of 400 mL. (d) Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 L0343.0 CuSOmol365.0 L g60.159 CuSOmolCuSOg00.2 CuSOg00.2mL200 100 1 solnmL CuSOg00.1CuSO)v/w(%00.1 4 4 4 4 4 4 =×× =××≡ Take 34.3 mL of the 0.365 M CuSO4 and dilute to a final volume of 200 mL using water. (e) L0169.0 NaOHmol062.19 LNaOHmol3225.0requiredNaOH)w/w(%50volume L NaOHmol062.19 g00.40 NaOHmol L mL1000 mL waterg waterg reagentg525.1 100 1 reagentg NaOHg50NaOH)w/w(%50 NaOHmol3225.0L50.1 L NaOHmol215.0NaOHM215.0 =×= = ×××××≡ =×≡ Take 16.9 mL of the concentrated reagent and dilute to a final volume of 1.50 L using water. (f) 64 64644 41 1 )CN(FeKg0424.0 mol )CN(FeKg35.368 Kmol4 )CN(FeKmolKmol1060.4 Kmol1060.4 g10.39 Kmol mg1000 gKmg108.1 Kmg108.1L50.1 solnL Kmg12Kppm0.12 =××× ×=××× ×=×≡ + +− +− + + + + + Dissolve 42.4 mg K4Fe(CN)6 in enough water to give a final volume of 1.50 L. 4-31 − − − − +− + + ×=××≡ ×=××≡ 3 23 3 32 3 3 IOmol1027.2mL0.75 mL1000 L L IOmol302.0IOM302.0 Lamol1025.1mL0.50 mL1000 L L Lamol250.0LaM250.0 Because each mole of La(IO3)3 requires three moles IO3-, IO3- becomes the limiting Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 reagent. Thus, formed)IO(Lag01.5 mol )IO(Lag6.663 IOmol3 )IO(LamolIOmol1027.2 3333 3 33 3 2 =××× − − − 4-32 −− − − +− + + ×=××≡ ×=××≡ Clmol1000.7mL400 mL1000 L L Clmol175.0ClM175.0 Pbmol1050.2mL200 mL1000 L L Pbmol125.0PbM125.0 2 22 2 2 Because each mole of PbCl2 requires two moles Cl-, Pb2+ becomes the limiting reagent. Thus, formedPbClg95.6 mol PbClg10.278 Pbmol PbClmolPbmol1050.2 222 222 =××× + +− 4-33 A balanced chemical equation can be written as shown below. )(COOHNaCl2HCl2CONa 2232 g++→+ (a) HClmol1031.7mL0.100 mL1000 L L HClmol0731.0HClM0731.0 CONamol10094.2 g99.105 CONamolCONag2220.0 3 32 332 32 − − ×=××≡ ×=× Because one mole of CO2 is evolved for every mole Na2CO3 reacted, Na2CO3 is the limiting reagent. Thus, evolvedCOg09218.0 mol COg01.44 CONamol COmolCONamol10094.2 22 32 2 32 3 =××× − Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 (b) HClM0312.0 L mL1000 mL0.100 HClmol1012.3 mol1012.3))mol10094.2(2(mol1031.7leftHClmol 3 333 =× × ×=××−×= − −−− 4-34 A balanced chemical equation can be written as shown below. 433343 POHgNaNO3HgNO3PONa +→+ (a) 3 3 3 42 343 43 HgNOmol05151.0mL0.100 mL1000 L L HgNOmol5151.0HgNOM5151.0 PONamol1039.9mL0.25 mL1000 L L PONamol3757.0PONaM3757.0 =××≡ ×=××≡ − The limiting reagent is Na2PO4. Thus, formedPOHgg54.6 mol POHgg74.696 PONamol POHgmolPONamol1039.9 4343 43 43 42 3 =××× − (b) 3 3 3 32 3 HgNOM187.0 L mL1000 mL0.125 HgNOmol0233.0 HgNOmol0233.0))mol1039.9(3(mol10151.5unreactedHgNOmol =× =××−×= −− 4-35 A balanced chemical equation can be written as shown below. )(SOOHNaClO2HClO2SONa 224432 g++→+ (a) 32 32 32 SONa mol 23490.0mL 00.75 mL 1000 L L SONa mol 3132.0SONa M 3132.0 =××≡ 4 4 4 HClOmol 06038.0mL 0.150 mL 1000 L L HClOmol 4025.0 M HClO4025.0 =××≡ Because one mole SO2 is evolved per mole Na2SO3, Na2SO3 is the limiting reagent. Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 Thus, evolved SO g 505.1 moL SO g 64.06 SONa mol SO molSONa mol 02349.0 22 32 2 32 =×× (b) 4 4 44 M HClO0595.0 L mL 1000 mL 225.0 HClOmol 0.01340 HClOmol 13400.0mol)) (0.023492-mol (0.06038unreacted HClOmol =× =×= 4-36 A balanced chemical equation can be written as shown below. −++ ++→++ Cl2Na2)(POMgNHNHPONaMgCl 444422 s 2 22 2 MgClmol02101.0 g21.95 MgClmol mL0.200 100 1 mL MgClg000.1MgCl)v/w(%000.1 = ×××≡ 42 342 42 PONamol1001.7mL0.40 mL1000 L L PONamol1753.0PONaM1753.0 −×=××≡ The Na2PO4 is the limiting reagent. Thus, 2 2 2 3 2 44 443 44 MgClM0583.0 L mL1000 mL240.0 MgClmol0.0140 MgClmol0140.0)1001.702101.0(unreactedMgClmol PO MgNHg 9628.0 mol PO MgNHg 137.351001.7ppt PO MgNHmass =× =×−= =××= − − 4-37 A balanced chemical equation can be written as shown below. −+ ++→+ 33 NOK)(AgIKIAgNO s 3 3 3 3 AgNOmL2930 L mL1000 AgNOmol0100.0 L KImol AgNOmolKImol02930.0 KImol02930.0 g0.166 KImol mL0.200 mL g ppt10 1KIppt31.24 =××× =×××× 2930 mL of 0.0100 M AgNO3 would be required to precipitate all I- as AgI. Fundamentals of Analytical Chemistry: 8th ed. Chapter 4 4-38 A balanced chemical equation can be written as shown below. −+ ++→+ 3 3 434223 NO6Al2BaSO3)SO(Al)NO(Ba3 (a) 342 3 342 342 23 3 23 623 )SO(Almol1018.6 mL0.200 mL1000 L L )SO(Almol03090.0)SO(AlM03090.0 )NO(Bamol1038.1 g34.261 )NO(Bamol mL0.750 mL g ppm10 1)NO(Bappm4.480 − − ×= ××≡ ×= ×××× The Ba(NO3)2 is the limiting reagent. Thus, formedBaSOg322.0 mol BaSOg39.233 )NO(Bamol3 BaSOmol3)NO(Bamol1038.1 44 23 4 23 3 =××× − (b) 342 3342 3 342 333 342 )SO(AlM1002.6 L mL1000 mL0.950 )SO(Almol1072.5 )SO(Almol1072.5))1038.1(31(1018.6(unreacted)SO(Almol − − −−− ×=× × ×=××−×=
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