47374 06 p43-66sciences.unlv.edu/Chemistry/hatchett/pdf/103/CH06Solutions.pdf · c. d. One mol...

43

6Chemical Quantities

6.1 a.

b.

c.

6.2 a.

b.

c.

6.3 a.

b.

c.

6.4 a.

b.

c.

6.5 a.

b.

c.

1 atom O !16.00 amu1 atom O

"16.00 amu46.07 amu (formula mass)

6 atoms H !1.008 amu1 atom H

" 6.048 amu

2 atoms C !12.01 amu1 atom C

" 24.02 amu

6 atoms O !16.00 amu1 atom O

"96.00 amu

164.10 amu (formula mass)

2 atoms N !14.01 amu1 atom N

" 28.02 amu

1 atom Ca !40.08 amu1 atom Ca

" 40.08 amu

6 atoms F !19.00 amu1 atom F


1 atom S !32.07 amu1 atom S

" 32.07 amu

128 000 amu Sr !1 atom Sr

87.62 amu Sr " 1.46 ! 103 atoms Sr

6400 amu Kr !1 atom Kr

83.80 amu Kr " 76 atoms Kr

1.60 ! 104 amu Cu !1 atom Cu

63.55 amu Cu " 2.52 ! 102 atoms Cu

35 000 amu Ne !1 atom Ne

20.18 amu Ne " 1.7 ! 103 atoms Ne

2.95 amu Ag !1 atom Ag

107.9 amu Ag " 2.73 ! 102 atoms Ag

540 amu Al !1 atom Al

26.98 amu Al " 20 atoms Al

9.15 ! 1025 Cl atoms !35.45 amu1 Cl atom

" 3.24 ! 1027 amu

2.80 ! 103 P atoms !30.97 amu1 P atom

" 8.67 ! 104 amu

75 Ba atoms !137.3 amu1 Ba atom

" 1.030 ! 104 amu

6.24 ! 1020 F atoms !19.00 amu1 F atom

" 1.19 ! 1022 amu

1.50 ! 105 Cr atoms !52.00 amu1 Cr atom

" 7.80 ! 106 amu

25 O atoms !16.00 amu1 O atom

" 400.0 amu (4.000 ! 102 amu)

47374_06_p43-66.qxd 2/9/07 8:40 AM Page 43

44

Chapter 6

d.

6.6 a.

b.

c.

d.

6.7 a.

b.


"3.024 amu



" 48.00 amu

1 atom Al !26.98 amu1 atom Al

" 26.98 amu


"48.00 amu



" 32.07 amu

2 atoms Na !22.99 amu1 atom Na

" 45.98 amu


"32.00 amu


4 atoms N !14.01 amu1 atom H

" 56.04 amu

10 atoms H !1.008 amu1 atom N

" 10.08 amu


" 96.08 amu




" 8.064 amu


" 36.03 amu




" 8.064 amu

1 atom C !12.01 amu1 atom C

" 12.01 amu


" 28.02 amu



2 atoms Cl !35.45 amu1 atom Cl

" 70.90 amu


"96.00 amu



" 12.10 amu


" 72.06 amu

47374_06_p43-66.qxd 2/9/07 8:40 AM Page 44

c.

d.

6.8 a.

b.

c.

d.

6.9 The mole is a unit that contains particles (atoms, molecules of a covalent substance,ions, or formula units of an ionic substance).

6.10 Avogadro’s number is , which is the number of particles in a mole.

6.11 One mol of chlorine atoms contains atoms chlorine; 1 mol of chlorine moleculescontains molecules chlorine, which is or atomschlorine.

1.204 ! 10242 ! 6.022 ! 10236.022 ! 10236.022 ! 1023

6.022 ! 1023

6.022 ! 1023

2 atoms Cl !35.45 amu1 atom Cl

" 70.90 amu300.1 amu

6.048 amu6 atoms H !1.008 amu1 atom H

"

28.02 amu2 atoms N !14.01 amu1 atom N

"

195.1 amu1 atom Pt !195.1 amu1 atom Pt

"


" 128.0 amu386.1 amu (formula mass)

2 atoms P !30.97 amu1 atom P

" 61.94 amu

3 atoms Zn !65.41 amu1 atom Zn

" 196.2 amu


" 64.00 amu



" 32.07 amu


" 8.064 amu


" 28.02 amu


" 48.00 amu


1 atom C !12.01 amu1 atom Ca

" 12.01 amu

1 atom Ca !40.08 amu1 atom Ca

" 40.08 amu


" 128.0 amu310.1 amu (formula mass)

2 atoms P !30.97 amu1 atom P

" 61.94 amu

3 atoms Ca !40.08 amu1 atom Ca

" 120.2 amu


"64.00 amu



" 32.07 amu

1 atom Fe !55.85 amu1 atom Fe

" 55.85 amu

Chemical Quantities

45

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46

Chapter 6

6.12 1 mol of N atoms is atoms of N, whereas 1 mol of molecules is molecules of . There are two N atoms in an N2 molecule, so there would be twice as many Natoms in 1 mol of molecules as in 1 mol of N atoms.

6.13 a.

b.

c.

d.

6.14 a.

b.

c.

d.

6.15 One mol molecules contains 3 mol H atoms, 1 mol P atoms, and 4 mol O atoms.

a.

b.

c.

d.

6.16 1 mol molecules contains 6 mol C atoms, 10 mol H atoms, and 1 mol O atoms.

a.

b.

c.

d.

6.17 a.

b.

3 mol O !16.00 g O1 mol O

" 48.00 g O

159.7 g Fe2O3 (molar mass)

2 mol Fe !55.85 g Fe1 mol Fe

" 111.7 g Fe

1 mol Cl !35.45 g Cl1 mol Cl

"35.45 g Cl58.44 g NaCl (molar mass)

1 mol Na !22.99 g Na1 mol Na

" 22.99 g Na

0.185 mol (C3H5)2O !6 mol C

1 mol (C3H5)2O!

6.022 ! 1023 atoms C1 mol C

" 6.68 ! 1023 C atoms

0.185 mol (C3H5)2O !10 mol H

1 mol (C3H5)2O!

6.022 ! 1023 atoms H 1 mol H

" 1.11 ! 1024 H atoms

0.185 mol (C3H5)2O !1 mol O

1 mol (C3H5)2O" 0.185 mol O

0.185 mol (C3H5)2O !6 mol C

1 mol (C3H5)2O" 1.11 mol C

(C3H5)2O

2.00 mol H3PO4 !4 mol O

1 mol H3PO4!

6.022 ! 1023 atoms O1 mol O

" 4.82 ! 1024 O atoms

2.00 mol H3PO4 !1 mol P

1 mol H3PO4!

6.022 ! 1023 atoms P1 mol P

" 1.20 ! 1024 P atoms

2.00 mol H3PO4 !4 mol O

1 mol H3 PO4" 8.00 mol O

2.00 mol H3PO4 !3 mol H

1 mol H3PO4" 6.00 mol H

H3PO4

3.754 ! 1023 molecules C2H6 !1 mol C2H6

6.022 ! 1023 molecules C2H6" 0.6234 mol C2H6

7.8 ! 1021 atoms Cu !1 mol Cu

6.022 ! 1023 atoms Cu" 0.013 mol Cu

0.0180 mol CO2 !6.022 ! 1023 atoms CO2

1 mol CO2" 1.08 ! 1022 CO2 molecules

4.5 mol Li !6.022 ! 1023 atoms Li

1 mol Li" 2.7 ! 1024 Li atoms

8.50 ! 1024 molecules C2H5OH !1 mol C2H5OH

6.022 ! 1023 molecules C2H5OH" 14.1 mol C2H5OH

5.22 ! 1022 atoms Fe !1 mol Fe

6.022 ! 1023 atoms Fe" 0.0867 mol Fe

1.28 mol SO2 !6.022 ! 1023 molecules SO2

1 mol SO2" 7.71 ! 1023 SO2 molecules

0.500 mol C !6.022 ! 1023 atoms C

1 mol C" 3.01 ! 1023 C atoms

N2

N2

6.022 ! 1023N26.022 ! 1023

47374_06_p43-66.qxd 2/9/07 8:40 AM 6

c.

d. One mol contains 2 mol Al, 3 mol S, and 12 mol O.

e.

f. One mol contains 16 mol C, 19 mol H, 3 mol N, 5 mol O, and 1 mol S.

6.18 a.

b.


" 48.00 g O

101.96 g (molar mass)

2 mol Al !26.98 g Al1 mol Al

" 53.96 g Al


" 64.00 g O


1 mol S !32.07 g S1 mol S

" 32.07 g S


" 55.85 g Fe


" 32.07 g S

365.5 g C16H19N3O5S


" 80.00 g O

3 mol N !14.01 g N1 mol N

" 42.03 g N

19 mol H !1.008 g H1 mol H

" 19.15 g H

16 mol C !12.01 g C1 mol C

" 192.2 g C

C16H19N3O5S

5 mol H !1.008 g H1 mol H

" 5.040 g H

188.18 g KC4H5O6 (molar mass)


" 96.00 g O

4 mol C !12.01 g C1 mol C

" 48.04 g C

1 mol K !39.10 g K1 mol K

" 39.10 g K

12 mol O !16.00 g O1 mol O

" 192.0 g O342.2 g Al2(SO4)3


" 96.21 g S


" 53.96 g Al

Al2(SO4)3


" 14.01 g N

277.4 g C2OH23N (molar mass)

23 mol H !1.008 g H1 mol H

" 23.18 g H

20 mol C !12.01g C1 mol C

" 240.2 g C

Chemical Quantities

47

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48

Chapter 6

c.

d.

e.

f.

6.19 a.

b.

c.


" 128.0 g O262.9 g C3H6O3

2 mol P !30.97 g P1 mol P

" 61.94 g P

3 mol Mg !24.31 g Mg1 mol Mg

" 72.93 g Mg


" 48.00 g O90.08 g C3H6O3


" 6.048 g H


" 36.03 g C


" 70.90 g Cl2


" 64.00 g O



" 6.048 g H


" 48.04 g C

1 mol Zn !65.41 g Zn1 mol Zn

" 65.41 g Zn


" 48.00 g O96.09 g (molar mass)


" 12.01 g C


" 8.064 g H

2 mol N !14.01 g H1 mol N

" 28.02 g N


" 16.00 g O60.09 g (molar mass)


" 8.064 g H


" 36.03 g C


" 32.07 g S



" 48.00 g O


" 14.01 g N


" 5.040 g H


" 84.07 g C

47374_06_p43-66.qxd 2/9/07 8:40 AM Page 48

d.

e.

f.

6.20 a.

b.

c.

d.

e.

f.


" 64.00 g O

183.00 g

1 mol Br !79.90 g Br1 mol Br

" 79.90 g Br


" 39.10 g K


" 144.0 g O319.4 g


" 36.03 g C

2 mol Ga !69.72 g Ga1 mol Ga

" 139.4 g Ga


" 64.00 g120.10 g


" 8.064 g H


" 48.04 g C

12 mol O !16.00 g O1 mol O

" 192.0 g O354.3 g


" 106.4 g Cl


" 55.85 g Fe


" 64.00 g136.09 g


" 30.97 g P


" 2.016 g H


" 39.10 g Mg

2 mol O !16.00 g O2

1 mol O " 32.00 g O2

2 mol F !19.00 g F1 mol F

" 38.00 g F

156.7 g SnF2

1 mol Sn !118.7 g Sn1 mol Sn

" 118.7 g Sn


" 70.90 g Cl98.95 g C2H4Cl2


" 4.032 g H


" 24.02 g C


" 57.00 g O83.98 g AlF3


" 26.98 g Al

Chemical Quantities

49

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50

Chapter 6

6.21 a.

b.

c.

d.

e.

6.22 a.

b.

c.

d.

e.

6.23 a.

b.

c.

d.

e.

6.24 a.

b.

c.

d.

e.

6.25 a.

b.

c. 15.0 g NH3 !1 mol NH3

17.03 g NH3 " 0.881 mol NH3

0.188 g C !1 mol C

12.01 g C " 0.0240 mol C

82.0 g Ag !1 mol Ag

107.9 g Ag " 0.760 mol Ag

2.28 mol SF6 !146.07 g SF6

1 mol SF6 " 333 g SF6

2.28 mol Mg(HCO3)2 !146.35 g Mg(HCO3)2

1 mol Mg(HCO3)2 " 334 g Mg(HCO3)2

2.28 mol C3H6O3 !90.08 g C3H6O3

1 mol C3H6O3 " 205 g C3H6O3

2.28 mol SO3 !80.07 g SO3

1 mol SO3 " 183 g SO3

2.28 mol N2 !28.02 g N2

1 mol N2 " 63.9 g N2

0.150 mol C6H14 !86.17 g C6H14

1 mol C6H14 " 12.9 g C6H14

0.150 mol Ca(NO3)2 !164.10 g Ca(NO3)2

1 mol Ca(NO3)2 " 24.6 g Ca(NO3)2

0.150 mol Na2O !61.98 g Na2O1 mol Na2O

" 9.30 g Na2O

0.150 mol I2 !253.8 g I2

1 mol I2 " 38.1 g I2

0.150 mol Ne !20.18 g Ne1 mol Ne

" 3.03 g Ne

2.08 mol (NH4)2SO4 !132.15 g (NH4)2SO4

1 mol (NH4)2SO4 " 275 g (NH4)2SO4

0.145 mol C2H6O !46.07 g C2H6O1 mol C2H6O

" 6.68 g C2H6O

3.52 mol MgBr2 !184.11 g MgBr2

1 mol MgBr2 " 648 g MgBr2

0.75 mol Cu !63.55 g Cu1 mol Cu

" 48 g Cu

5.12 mol Al !26.98 g Al1 mol Al

" 138 g Al

7.14 ! 102 mol PCl3 !137.32 g PCl3

1 mol PCl3 " 9.80 ! 104 g PCl3

0.0485 mol Na2CO3 !105.99 g Na2CO3

1 mol Na2CO3 " 5.14 g Na2CO3

0.125 mol CO2 !44.01 g CO2

1 mol CO2 " 5.50 g CO2

2.80 mol Ca !40.08 g Ca1 mol Ca

" 112 g Ca

1.50 mol Na !22.99 g Na1 mol Na

" 34.5 g Na

47374_06_p43-66.qxd 2/9/07 8:40 AM Page 50

d.

e.

6.26 a.

b.

c.

d.

e.

6.27 a.

b.

c.

d.

e.

6.28 a.

b.

c.

d.

e.

6.29 a.

b.

c.

d.

e. 7.5 ! 1024 molecules CH4 !1 atom C

1 molecule CH4" 7.5 ! 1024 C atoms

1.84 mol C2H6O !2 mol C

1 mol C2H6O!

6.022 ! 1023 C atoms1 mol C

" 2.22 ! 1024 C atoms

1.13 ! 1025 C atoms

275 g C3H8 !1 mol C3H8

44.09 g C3H8!

3 mol C 1 mol C3H8

!6.022 ! 1023 C atoms

1 mol C"

0.688 mol C !6.022 ! 1023 C atoms

1 mol C" 4.14 ! 1024 C atoms

25.0 g C !1 mol C

12.01 g C!

6.022 ! 1023 C atoms1 mol C

" 1.25 ! 1024 C atoms

4.00 g C6H8O6 !1 mol C6H8O6

176.12 g C6H8O6 " 0.0227 mol C6H8O6

4.00 g Ca3N2 !1 mol Ca3N2

148.28 g Ca3N2 " 0.0270 mol Ca3N2

4.00 g Cr(OH)3 !1 mol Cr(OH)3

103.02 g Cr(OH)3 " 0.0388 mol Cr(OH)3

4.00 g SnO2 !1 mol SnO2

150.7 g SnO2 " 0.0265 mol SnO2

4.00 g He !1 mol He

4.003 g He " 0.999 mol He

25.0 g C4H10 !1 mol C4H10

58.12 g C4H10 " 0.430 mol C4H10

25.0 g Ga2S3 !1 mol Ga2S3

235.65 g Ga2S3 " 0.106 mol Ga2S3

25.0 g Al(OH)3 !1 mol Al(OH)3

78.00 g Al(OH)3 " 0.320 mol Al(OH)3

25.0 g O2 !1 mol O2

32.00 g O2 " 0.781 mol O2

25.0 g He !1 mol He

4.003 g He " 6.25 mol He

252.8 g C6H12O6 !1 mol C6H12O6

180.16 g C6H12O6 " 1.403 mol C6H12O6

308 g BaSO4 !1 mol BaSO4

233.4 g BaSO4 " 1.32 mol BaSO4

6.4 g H2O !1 mol H2O

18.02 g H2O " 0.36 mol H2O

144 g K !1 mol K

39.10 g K " 3.68 mol K

85.2 g Ni !1 mol Ni

58.69 g Ni " 1.45 mol Ni

245 g Fe2O3 !1 mol Fe2O3

159.7 g Fe2O3 " 1.53 mol Fe2O3

7.25 g C3H8 !1 mol C3H8

44.09 g C3H8 " 0.164 mol C3H8

Chemical Quantities

51

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52

Chapter 6

6.30 a.

b.

c.

d.

e.

6.31 a.

b.

c.

d.

6.32 a. 0.203 mol Sb.c. 50.3 g Cd.

6.33 a.

b.

2.016 g H74.10 g Ca(OH)2

! 100% " 2.72% H (rounded to 0.01%)

32.00 g O74.10 g Ca(OH)2

! 100% " 42.18% O

40.08 g Ca74.10 g Ca(OH)2

! 100% " 54.09% Ca


" 2.016 g H

74.10 g Ca(OH)2


" 32.00 g O

1 mol Ca !40.08 g Ca1 mol Ca

" 40.08 g Ca

38.00 g F62.31 g MgF2

! 100% " 60.99% F

24.31 g Mg62.31 g MgF2

! 100% " 39.01% Mg


" 38.00 g F62.31 g MgF2

1 mol Mg !24.31 g Mg1 mol Mg

" 24.31 g Mg

4.75 ! 1023 C atoms

4.5 ! 1024 atoms H

" 2.78 ! 1022 atoms H

0.254 g C3H8 !1 mol C3H8

44.09 g C3H8!

8 mol H1 mol C3H8

!6.022 ! 1023 atoms H

1 mol H

0.771 mol C3H8 !3 mol C

1 mol C3H8!

12.01 g C1 mol C

" 27.8 g C

34.0 g C3H8 !1 mol C3H8

44.09 g C3H8" 0.771 mol propane (C3H8)

1.50 mol C3H8 !44.09 g C3H8

1 mol C3H8" 66.1 g propane (C3H8)

1.4 ! 1022 molecules N2O4 !2 atoms N

1 molecule N2O4" 2.8 ! 1022 N atoms

6.24 ! 10#3 mol NH3 !1 mol N

1 mol NH3!

6.022 ! 1023 N atoms1 mol N

" 3.76 ! 1021 N atoms

40.0 g N2O !1 mol N2O

44.02 g N2O!

2 mol N1 mol N2O

!6.022 ! 1023 N atoms

1 mol N" 1.09 ! 1024 N atoms

5.8 ! 1021 N atoms

0.82 g NaNO3 !1 mol NaNO3

85.00 g NaNO3!

1 mol N1 mol NaNO3

!6.022 ! 1023 N atoms

1 mol N"

0.755 mol N2 !2 mol N1 mol N2

!6.022 ! 1023 N atoms

1 mol N" 9.09 ! 1023 N atoms

47374_06_p43-66.qxd 2/9/07 8:40 AM Page 52

c.

d.

e.

48.00 g O285.3 g C17H19NO3

! 100% " 16.82% O

14.01 g N285.3 g C17H19NO3

! 100% " 4.91% N (rounded to 0.01%)

19.15 g H285.3 g C17H19NO3

! 100% " 6.71% H (rounded to 0.01%)

204.2 g C285.3 g C17H19NO3

! 100% " 71.56% C


" 48.00 g O

285.3 g C17H19NO3


" 14.01 g N

19 mol H !1.008 g H1 mol H

" 19.15 g H

17 mol C !12.01 g C1 mol C

" 204.2 g C

64.00 g O149.10 g C4H8O4

! 100% " 42.92% O

30.97 g P149.10 g C4H8O4

! 100% " 20.77% P

12.10 g N149.10 g C4H8O4

! 100% " 8.12% H (rounded to 0.01%)

43.03 g N149.10 g C4H8O4

! 100% " 28.19% N


" 64.00 g O

149.10 g C4H8O4


" 30.97 g P

12 mol H !1.008 g H1 mol H

" 12.10 g H


" 42.03 g N

64.00 g O120.10 g C4H8O4

! 100% " 53.29% O

8.064 g H120.10 g C4H8O4

! 100% " 6.71% H (rounded to 0.01%)

48.04 g C120.10 g C4H8O4

! 100% " 40.00% C


" 64.00 g O

120.10 g C4H8O4


" 8.06 g H (rounded to 0.01%)


" 48.04 g C

Chemical Quantities

53

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54

Chapter 6

6.34 a. 36.11% Ca; 63.89% Clb. 17.55% Na; 39.70% Cr; 42.75% Oc. 18.01% C; 2.27% H; 79.73% Cld. 38.76% Ca; 19.97% P; 41.27% Oe. 75.99% C; 12.76% H; 11.25% O

6.35 a.

b.

c.

d.

e.

28.02 g N234.3 g C14H22N2O

! 100% " 11.96% N


" 16.00 g O

234.3 g C14H22N2O


" 28.02 g N

22 mol H !1.008 g H1 mol H

" 22.18 g H

14 mol C !12.01 g C1 mol C

" 168.1 g C

70.05 g N209.3 g C9H15N5O

! 100% " 33.48% N


" 16.00 g O

209.3 g C9H15N5O


" 70.05 g N

15 mol H !1.008 g H1 mol H

" 15.12 g H


" 108.0 g C

28.02 g N60.10 g C2H8N2

! 100% " 46.62% N


" 28.02 g N60.10 g C2H8N2


" 8.064 g H


" 24.02 g C

28.02 g N80.05 g NH4NO3

! 100% " 35.00% N


" 48.00 g O80.05 g NH4NO3


" 4.032 g H

2 mol N !14.01 g N1 mol H

" 28.02 g N

28.02 g N108.20 g N2O5

! 100% " 25.94% N


" 80.00 g O

108.20 g N2O5


" 28.02 g N

47374_06_p43-66.qxd 2/9/07 8:40 AM Page 54

6.36 a. 22.58% S b. 64.07% S c. 40.05% Sd. 41.04% S e. 12.81% S

6.37 a.

b.

c.

d.

6.38 a. b. c. d.

6.39 11.44 g compound (S and F)

Empirical formula " SF6

0.0783 mol S0.0783 mol

" 1.00 mol S 0.470 mol F0.0783

" 6.00 mol F

8.93 g F !1 mol F

19.00 g F" 0.470 mol F

2.51 g S !1 mol S

32.07 g S" 0.0783 mol S (smaller number of moles)

# 2.51 g S " 8.93 g F

K3PO4NaHSO4Na2OAg2S

0.205 mol O0.0512

" 4.00 mol O Empirical formula " CaCrO4

0.0514 mol Ca0.0512

" 1.00 mol Ca 0.0512 mol Cr0.0512

" 1.00 mol Cr

3.28 g O !1 mol O

16.00 g O " 0.205 mol O

2.66 g Cr !1 mol Cr

52.00 g Cr " 0.0512 mol Cr (smaller number of moles)

2.06 g Ca !1 mol Ca

1.008 g Ca " 0.0514 mol Ca

0.524 mol O0.174

" 3.01 mol O Empirical formula " HNO3

0.174 mol H0.174

" 1.00 mol H 0.174 mol N0.174

" 1.00 mol N

8.38 g O !1 mol O

16.00 g O " 0.524 mol O

2.44 g N !1 mol N

14.01 g N " 0.174 mol N (smaller number of moles)

0.175 g H !1 mol H

1.008 g H " 0.174 mol H

Empirical formula " CH3

0.583 mol C0.583

" 1.00 mol C 1.74 mol H0.583

" 2.98 mol H : 3

1.75 g H !1 mol H

1.008 g H" 1.74 mol H

7.00 g C !1 mol C

12.01 g C" 0.583 mol C (smaller number of moles)

Empirical formula " N2O

0.255 mol N0.128

" 1.99 mol N : 2 0.128 mol O0.128

" 1.00 mol O

2.04 g O !1 mol O

16.00 g O" 0.128 mol O (smaller number of moles)

3.57 g N !1 mol N

14.01 g N" 0.255 mol N

Chemical Quantities

55

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56

Chapter 6

6.40

6.41 a.

b.

c.

d.

e.

Empirical formula " C5H8O31.00 mol O ! 3 " 3.00 mol O2.66 mol H ! 3 " 7.98 mol H : 8 H1.67 mol C ! 3 " 5.01 mol C : 5 C

2.58 mol O2.58

" 1.00 mol O

6.85 mol H2.58

" 2.66 mol H4.31 mol C

2.58" 1.67 mol C

41.3 g O !1 mol O

16.00 g O" 2.58 mol O (smaller number of moles)

6.90 g H !1 mol H

1.008 g H" 6.85 mol H51.7 g C !

1 mol C12.01 g C

" 4.31 mol C

Empirical formula " Li2CO34.06 mol O

1.36" 2.98 mol : 3 O

1.36 mol C1.36

" 1.00 mol C2.71 mol Li

1.36" 1.99 mol Li : 2 Li

64.9 g O !1 mol O

16.00 g O " 4.06 mol O

16.3 g C !1 mol C

12.01 g C " 1.36 mol C (smaller number of moles)

18.8 g Li !1 mol Li

6.941 g Li " 2.71 mol Li

Empirical formula " B2O3

1.50 mol O ! 2 " 3.00 mol O1.00 mol B ! 2 " 2.00 mol B

2.87 mol B2.87

" 1.00 mol B 4.31 mol O2.87

" 1.50 mol O

69.0 g O !1 mol O

16.00 g O" 4.31 mol O

31.0 g B !1 mol B

10.81 g B" 2.87 mol B (smaller number of moles)

Empirical formula " GaF3

0.789 mol S0.789

" 1.00 mol Ga 2.36 mol F0.789

" 2.99 mol F : 3 F

45.0 g F !1 mol F

19.00 g F " 2.36 mol F

55.0 g Ga !1 mol Ga

69.72 g Ga " 0.789 mol Ga (smaller number of moles)

Empirical formula " K2S

1.81 mol K0.907

" 2.00 mol K 0.907 mol S0.907

" 1.00 mol S

29.1 g S !1 mol S

32.07 g S " 0.907 mol S (smaller number of moles)

70.9 g K !1 mol K

39.01 g K " 1.81 mol K

Fe2O3

47374_06_p43-66.qxd 2/9/07 8:40 AM Page 56

6.42 a. CaS b. c. d. e.

6.43 a. HO and b. and c.d.e.

6.44 a. b. c. d. CCl e.

6.45

6.46

6.47

6.48

6.49 In 100 g of compound, there is 48.64 g C, 8.16 g H, and 43.20 g O.

2 ! (Empirical formula C3H6O2) " Molecular formula C6H12O4

148 g (molar mass)74.08 g (mass of empirical formula)

" 2.00

Mass of C3H6O2 " 3 ! 12.01 $ 6 ! 1.008 $ 2 ! 16.00 " 74.08 gEmpirical formula " C3H6O2

1.00 mol O ! 2 " 2.00 mol O3.00 mol O ! 2 " 6.00 mol H1.50 mol C ! 2 " 3.00 mol C

2.70 mol O2.70

" 1.00 mol O

4.050 mol C2.70

" 1.50 mol C 8.10 mol H

2.70 " 3.00 mol H

Moles of O " 43.20 g O ! 1 mol O

16.00 g O " 2.70 mol O (smaller number of moles)

Moles of H " 8.16 g H ! 1 mol H

1.008 g H " 8.10 mol H

Moles of C " 48.64 g C ! 1 mol C

12.01 g C " 4.050 mol C

CHO ! 6 " C6H6O6Acontic acid 174.1 g (molar mass)

29.02 g (mass of empirical formula)" 6.0

CHO ! 4 " C4H4O4Maleic acid 116.1 g (molar mass)29.02 g (mass of empirical formula)

" 4.0

CHO ! 2 " C2H2O2Glyoxyl 58 g (molar mass)29.02 g (empirical mass)

" 2.0

Mass of empirical formula CHO " 12.01 $ 1.008 $ 16.00 " 29.02g

CH ! 2 " C2H2Acetylene 26 g (molar mass)13.02 g (mass of empirical formula)

" 2.0

CH ! 6 " C6H6Benzene 78 g (molar mass)13.02 g (empirical mass)

" 6.0

Mass of empirical formula CH " 12.01 $ 1.008 " 13.02 g

C8H10N4O2

CH2O ! 6 " C6H12O6180 g (molar mass)

30.03 g (empirical mass)" 6

Mass of CH2O " 12.01 $ 2(1.008) $ 16.00 " 30.03 g

C6H4O3B3H5CH2OC2H2O

2O % 2 " 1O2N % 2 " 1N4H % 2 " 2H2C % 2 " 1CCH2NO6N % 3 " 2N18H % 3 " 6H9C % 3 " 3CC3H6N2

2O % 2 " 1O16H % 2 " 8H10C % 2 " 5CC5H8O12H % 6 " 218C % 6 " 3CC3H2

2O % 2 " 1O2H % 2 " 1H

C3H4Cl4Na2S2O3Zn3P2BaF2

Chemical Quantities

57

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58

Chapter 6

6.50 The empirical formula is , and the molecular formula is .

6.51 In 100 g of compound, there are 54.14 g C, 4.80 g H, and 38.06 g O.


6.53 In 100 g of compound, there are 74.0 g C and 8.7 g H.

6.54 The empirical formula is CHN, and the molecular formula is .

6.55 a.

b.


" 32.00 g O


" 28.02 g N


" 8.064 g H

10 mol C !12.01 g C1 mol C

" 120.1 g C

C10H8N2O2S2 % 2 " C5H4NOS (empirical formula)

C5H5N5

2 ! (Empirical formula C5H7N) " Molecular formula C10H14N2


" 2.00

Mass of C5H7N1 " 5 ! 12.01 $ 7 ! 1.008 $ 1 ! 14.01 " 81.12 gEmpirical formula " C5H7N1

1.23 mol N1.23

" 1.00 mol N

6.16 mol C1.23

" 5.01 mol C 8.6 mol H

1.23 " 7.0 mol H

Moles of N " 17.3 g N ! 1 mol N

14.01 g N " 1.23 mol N (smallest number of moles)


1.008 g H " 8.6 mol H


12.01 g C " 6.16 mol C

100 g # (74.0 g $ 8.7 g) " 17.3 g N

C3H6O3CH2O

4 ! (Empirical formula C2H2O) " Molecular formula C8H8O4

168.1 g (molar mass)42.08 g (mass of empirical formula)

" 3.99 : 4.00

Mass of C2H2O1 " 2 ! 12.01 $ 2 ! 1.008 $ 1 ! 16.00 " 42.04 gEmpirical formula " C2H2O1

2.379 mol O2.379

" 1.00 mol O

4.758 mol C2.379

" 2.00 mol C 4.76 mol H

2.379 " 2.00 mol H




1.008 g H " 4.76 mol H


12.01 g C " 4.758 mol C

C2H3Cl3O2C2H3Cl3O2

47374_06_p43-66.qxd 2/9/07 8:40 AM Page 58

c.

d.

6.56 a. 15.51% O b.c. 1.13 g hydrogen d.

6.57 a.b. SClc.d.

6.58 a.b. CHc.d.

6.59 a.

b.


" 96.00 amu389.9 amu

2 I atoms !126.9 amu1 I atom

" 253.8 amu

1 Ca atom !40.08 amu1 Ca atom

" 40.08 amu


" 64.00 amu

151.92 amu

1 S atom !32.07 amu1 S atom

" 32.07 amu

1 Fe atom !55.85 amu1 Fe atom

" 55.85 amu

6.048 g H/72.06 g C6H6 ! 100% " 7.946% H6 mol H ! 1.008 g/mol H " 6.048 g H72.06 g C/72.06 g C6H6 ! 100% " 92.25% C6 mol C ! 12.01 g/mol C " 72.06 g C6 mol C ! 12.01 g/mol C # 6 mol H ! 1.008 g/mol H " 78.11 g (molar mass)

C6H6

70.90 g Cl/135.04 g S2Cl2 ! 100% " 52.50% Cl2 mol Cl ! 35.45 g/mol Cl " 70.90 g Cl64.14 g S/135.04 g S2Cl2 ! 100% " 47.50% S2 mol S ! 32.07 g/mol S " 64.14 g S2 mol S ! 32.07 g/mol S # 2 mol Cl ! 35.45 g/mol Cl " 135.04 g (molar mass)

S2Cl2

1.29 ! 1022 hydrogen atoms1.61 ! 1022 carbon atoms

6.8 mol C10H8N2O2S2

8.2 ! 1024 N atoms !1 mol N

6.022 ! 1023 N atoms!

1 mol C10H8N2O2S2

2 mol N"

6.022 ! 1023 C atoms1 mol C

" 5.97 ! 1023 C atoms

25.0 g C10H8N2O2S2 !1 mol C10H8N2O2S2

252.3 g C10H8N2O2S2!

10 mol C1 mol C10H8N2O2S2

!

64.14 g S252.3 g C10H8N2O2S2

! 100 " 25.42% S

32.00 g O252.3 g C10H8N2O2S2

! 100 " 12.68% O

28.04 g N252.3 g C10H8N2O2S2

! 100 " 11.10% N

8.064 g H252.3 g C10H8N2O2S2

! 100 " 3.20% H (rounded to 0.01%)

120.1 g C252.3 g C10H8N2O2S2

! 100 " 47.60% C


"64.14 g S

252.3 g C10H8N2O2S2

Chemical Quantities

59

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60

Chapter 6

c.

d.

6.60 a. 146.35 g/mol b. 248.0 g/mol c. 282.5 g/mol d. 358.4 g/mol

6.61 a.

b.

144.0 g O210.0 g Al(HCO3)3

! 100% " 68.57% O

36.03 g C210.0 g Al(HCO3)3

! 100% " 17.16% C

3.024 g H210.0 g Al(HCO3)3

! 100% " 1.44% H (rounded to 0.01%)

26.98 g Al210.0 g Al(HCO3)3

! 100% " 12.85% Al


" 144.0 g O210.0 g Al(HCO3)3


" 36.03 g C


" 3.024 g H


" 26.98 g Al

64.00 g O194.20 g K2CrO4

! 100% " 32.96% O

52.00 g Cr194.20 g K2CrO4

! 100% " 26.78% Cr

78.20 g K194.20 g K2CrO4

! 100% " 40.27% K


" 64.00 g O

194.20 g K2CrO4

1 mol Cr !52.00 g Cr1 mol Cr

" 52.00 g Cr


" 78.20 g K


" 32.00 amu

116.16 amu

12 H atoms !1.008 amu1 H atom

" 12.10 amu

6 C atoms !12.01 amu1 C atom

" 72.06 amu


" 64.00 amu

169.11 amu

1 Na atom !22.99 amu1 Na atom

" 22.99 amu

1 N atom !14.01 amu1 N atom

" 14.01 amu

8 H atoms !1.008 amu1 H atom

" 8.064 amu

5 C atoms !12.01 amu1 C atom

" 60.05 amu

47374_06_p43-66.qxd 2/9/07 8:40 AM Page 60

c.

6.62 a. 43.64% P b. 45.93% P c. 19.97% P

6.63 a.

b.

c.

d.

6.64 a. 21.20% Nb.c. 47.8 g oxygend. 10.3 g ammonium sulfate

6.65 a.

b.

c.

1.00 ! 1023 O atoms

7.50 g C9H8O4 !1 mol C9H8O4

90.08 g C9H8O4!

4 mol O1 mol C9H8O4

!6.022 ! 1023 O atoms

1 mol O"

0.923 mol C9H8O4 (aspirin)

5.00 ! 1024 C atoms !1 mol C

6.022 ! 1023 C atoms!

1 mol C9H8O4

9 mol C"

64.00 g O180.2 g C9H8O4

! 100 " 35.52% O

8.064 g H180.2 g C9H8O4

! 100 " 4.48% H (rounded to 0.01%)

108.1 g C180.2 g C9H8O4

! 100 " 59.99% O


" 64.00 g O

180.2 g C3H6O3


" 8.064 g H


" 108.01 g C

3.6 ! 1024 hydrogen atoms

C3H6O3 % 3 " CH2O (empirical formula)

3.50 g H !1 mol H

1.008 g H!

1 mol C3H6O3

6 mol H!

90.08 g C3H6O3

1 mol C3H6O3" 52.1 g C3H6O3

2.51 ! 1024 C atoms

125 g C3H6O3 !1 mol C3H6O3

90.08 g C3H6O3!

3 mol C1 mol C3H6O3

!6.022 ! 1023 C atoms

1 mol C"

48.00 g O90.08 g C3H6O3

! 100 " 53.29% O


" 48.00 g O90.08 g C3H6O3


" 6.048 g H


" 36.03 g C

96.00 g O180.16 g C6H12O6

! 100% " 53.29% O

96.00 g O180.16 g C6H12O6

! 100% " 6.71% H (rounded to 0.01%)

72.06 g C180.16 g C6H12O6

! 100% " 40.00% C


" 96.00 g

180.16 g

12 mol H !1.008 g H1 mol H

" 12.10 g6 mol C !12.01 g C1 mol C

" 72.06 g

Chemical Quantities

61

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62

Chapter 6

d.

6.66 a.b.c.d.

6.67 a.

b.

6.68 a. 115 g Cl b. 0.914 mol P

6.69 a.b.c.d.

6.70 a. b. c. d.

6.71 a.

b.

Empirical formula " AgNO3

0.177 mol O0.0589

" 3.01 mol O

0.0589 mol Ag0.0589

" 1.00 mol Ag 0.0589 mol N0.0589

" 1.00 mol N


16.00 g O " 0.177 mol O

Moles of N " 0.825 g N ! 1 mol N

14.01 g N " 0.0589 mol N

Moles of Ag " 6.35 g Ag ! 1 mol Ag

107.9 g Ag " 0.0589 mol Ag (smaller number of moles)

Empirical formula " SF6

0.0686 mol S0.0686

" 1.00 mol S 0.411 mol F0.0686

" 5.99 mol F : 6 mol F

7.81 g F !1 mol F

19.00 g F" 0.411 mol F

2.20 g S !1 mol S

32.07 g S" 0.0686 mol S (smaller number of moles)

C8H8NOCrCl3C2H2ONH2

C6H14N2O2 % 2 " C3H7NO (empirical formula)C16H16N4 % 4 " C4H4N (empirical formula)FeC2O4 % 1 " FeC2O4 (empirical formula)C5H5N5 % 5 " CHN (empirical formula)

12.6 g Mn $ 27.5 g Mn " 40.1 g Mn

0.250 mol Mn2O3 !2 mol Mn

1 mol Mn2O3!

54.94 g Mn1 mol Mn

" 27.5 g Mn

20.0 g MnO2 !1 mol MnO2

86.94 g MnO2!

1 mol Mn1 mol MnO2

!54.94 g Mn1 mol Mn

" 12.6 g Mn

1.210 mol O !6.022 ! 1023 O atoms

1 mol O" 7.287 ! 1023 O atoms, or 7.29 ! 1023 O atoms

0.750 mol O $ 0.460 mol O " 1.210 mol O

20.0 g MnO2 !1 mol MnO2

86.94 g MnO2!

2 mol O1 mol MnO2

" 0.460 mol O

0.250 mol Mn2O3 !3 mol O

1 mol Mn2O3" 0.750 mol O

2.3 ! 1021 hydroxide ions3.4 ! 1021 magnesium atoms6.6 ! 1021 calcium ions0.066 mol CaCO3

1.87 ! 1023 molecules (aspirin)

2.50 g H !1 mol H

1.008 g H!

1 mol C9H8O4

8 mol H!

6.022 ! 1023 molecules C9H8O4

1 mol C9H8O4"

47374_06_p43-66.qxd 2/9/07 8:40 AM Page 62

c.

6.72 a. b. c.

6.73 a. In 100 g of compound, there are 76.54 g C, 12.13 g H, and 11.33 g O.

b.

6.74 a. 9.85 g b. c. 0.0820 mol Fe

6.75 In 100 g of compound, there are 40.7 g C, 5.12 g H, and 54.2 g O.

2 ! (Empirical formula C2H3O2) " Molecular formula C4H6O4


" 2.00

Empirical formula " C2H3O2 " 2 ! 12.01 $ 3 ! 1.008 $ 2 ! 16.00 " 59.04 g1.00 mol C ! 2 " 2.00 mol C 1.50 mol H ! 2 " 3.00 mol H 1.00 mol O ! 2 " 2.00 mol O

3.39 mol O3.39

" 1.00 mol O

3.39 mol C3.39

" 1.00 mol C 5.08 mol H

3.39 " 1.50 mol H




1.008 g H " 5.08 mol H


12.01 g C " 3.39 mol C

FeS2

5.73 ! 1021 molecules of oleic acid

3.00 mL !0.895 g C18H34O2

1 mL!

1 mol C18H34O2

282.4 g C18H34O2!

6.022 ! 1023 molecules1 mol C18H34O2

"

2 ! (Empirical formula C9H17O) " Molecular formula C18H34O2


" 2.00

Empirical formula " C9H17O " 9 ! 12.01 $ 17 ! 1.008 $ 1 ! 16.00 " 141.2 g

0.7081 mol O0.7081

" 1.000 mol O

6.373 mol C0.7081

" 9.000 mol C 12.03 mol H

0.7081 " 16.99 : 17 mol H




1.008 g H " 12.03 mol H


12.01 g C " 6.373 mol C

AlPO4N2O5SnF4

Empirical formula " Au2O3

0.681 mol O0.453

" 1.50 mol O ! 2 " 3.00 mol O

0.453 mol Au0.453

" 1.00 mol Au ! 2 " 2.00 mol Au

10.9 g O !1 mol O

16.00 g O" 0.681 mol O

89.2 g Au !1 mol Au

197.0 g Au" 0.453 mol Au (smaller number of moles)

Chemical Quantities

63

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64

Chapter 6

6.76 Empirical formula ; Molecular formula

6.77 Moles of

Moles of

Moles of (smaller number of moles)

Empirical formula ; Molecular formulaMolar mass

6.78 Molecular formula

6.79 a. 0.00680 mol NaFb. ions are in the tube.c.d. triclosan molecules are in the tube.e. 49.78% C; 2.44% H; 36.73% Cl; 11.05% O



6.82 a.b. Au atomsc.d.

Answers to Combining Ideas Chapters 4–6

CI 6 a. b. calcium carbonate c. ions

CI 7 a. In 100 g oxalic acid,

Dividing each by 2.16,

Empirical formulab. Empirical formula mass

molecular formula(CHO2) ! 2 " C2H2O4

90. g molar mass/45.02 g EF " 2" 12.01 g C $ 1.008 g H $ 2(16.00 g O) " 45.02 g EF

" CHO2

4.44 mol O/2.16 " 2.06 mol O : 22.22 mol H/2.16 " 1.03 mol H : 12.16 mol C/2.16 " 1 mol C : 1

71.1 g O !1 mol O

16.00 g O" 4.44 mol O

2.24 g H !1 mol H

1.008 g H" 2.22 mol H

26.7 g C !1 mol C

12.01 g C" 2.16 mol C

6.02 ! 1021 Ca2$CaCO3

Au2O3

0.61 g oxygen1.52 ! 10225.00 g gold

Fe2Cr3O12Fe2Cr3O12

C6H8O2C3H4O

7.4 ! 10200.00197 g Na$4.10 ! 1021 F#

" SrO6Cl2

" 4 ! 12.01 $ 8 ! 1.008 $ 4 ! 16.00 " 120.10 g" CH2O ! 4 " C4H8O4" CH2O

0.274 mol O0.274

" 1.00 mol O

0.274 mol C0.274

" 1.00 mol C 0.548 mol H

0.274 " 2.00 mol H

O " 4.39 g O !1 mol O

16.00 g O" 0.274 mol O

H " 0.552 g H !1 mol H

1.008 g H" 0.548 mol H

C " 1.65 ! 1023atoms C !1 mol C

6.022 ! 1023atoms C" 0.274 mol C

" Hg2Cl2O6" HgClO3

47374_06_p43-66.qxd 2/9/07 8:40 AM Page 64

c.

d.

CI 8 a.b.c. 54.53% C, 9.15% H, 36.32% Od. 0.464 g Ce. 24.0 gf. 6.

CI 9 a.

b.

c.

d.

Total number of protons

CI 10 a. mol shikimic acidb. 59 capsulesc. 0.046 g Cd.e. 3 ! 104 lb

4 ! 102 kg

7.5 ! 10#3

" 92 protons

5 O atoms !8 protons1 O atom

" 40 protons

10 H atoms !1 proton1 H atom

" 10 protons

7 C atoms !6 protons1 C atom

" 42 protons

C7H10O5

32.00 g O312.40 g

! 100 " 20.49% O

28.02 g N312.40 g

! 100 " 8.97% N

28.88 g H312.40 g

! 100 " 9.03% H

192.16 g C312.40 g

! 100 " 61.51% C

8(12.01 g C) $ 14(1.008 g H) $ 14.01 g N $ 2(16.00 g O) " 312.40 g (molar mass)C8H14NO2

15 ! 10#3 mol butyric acid

C2H4OC4H8O2

27 g !100 g rhubarb leaves

0.5 g!

1 kg1000 g

" 5 kg rhubarb leaves

160 lb !1 kg

2.205 lb!

375 mg1 kg

!1 g

1000 mg" 27 g oxalic acid

Chemical Quantities

65

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