CAPTULO 6

6.14; 6.15; 6.16; 6.17; 6.19; 6.20; 6.24; 6.25; 6.26.

6.14 Dados: MF= 143,45; Kps= 5.10-9 a) S em mol/L: CuBr(s) Cu+(aq) + Br-(aq)Incio Slido Final x 0 X 0 x

X = solubilidade Kps = [Cu+].[Br-] 5.10-9=x.x

S=5.10-9=7,07.10-5 mol/L

b)

S em g/100 mL: 7,07.10-5 mol 1000mL y 100 mL

y= 7,07.10-6 mol em 100 mL1 mol CuBr 7,07.10-6 mol

145,45g S

S= 1,01.10- gramas em 100 mL

a)Incio

S em mol/L: Ag4Fe(CN)6(s) 4Ag+(aq) + Fe(CN)64-(aq)Slido 0 0

Final

x

4X

x

Kps=[Ag+]4.[Fe(CN)64-]=8,5.10-45 Kps=(4x)4.x Kps=256x5 S=5(8,5.10-45)/256

S= 5,06.10-10 mol/L

b)

gramas por 100 mL: 5,06.10-10 mol 1000 mL y 100 mL

y= 5,06.10-11 mol em 100 mL1 mol 5,06.10-11 mol S 643,42g

S= 3,26.10-8 gramas em 100 mL

c) ppb de Ag+ ( ng Ag+/mL): 3,26.10-8 g 100 mL x 1 mL x= 3,26.10-10 g/mL 1ng 10-9 g y 3,26.10-10g y=0,326 ng/mL 0,326ng 6 (x+4x+x linha final) z 4 (4x qntde de Ag+) z= 0,22 ng/mL

[Ag+]=0,22 ppb

AgCl(s)IncioFinal x

Ag+(aq)+Cl-(aq) Kps=1,8.10-100X

Slido

0x

Kps=[Ag+].[Cl-]=1,8.10-10 Kps=x.x kps=x x=[Ag+]=1,8.10-10=1,34.10-5 mol/L 1,34.10-5 mol Ag+ 1000mL y 1mL y= 1,34.10-8 mol Ag+/mL

1,34.10-8 mol Ag+ 1 mol

z=1,4.10-6 g de Ag+/mL1 ng w 10-9g 1,4.10-6g

z 107,87

w= 1400 ng/mL

[Ag+] = 1400 ppb

AgBr(s)IncioFinal

Ag+(aq)+Br-(aq) Kps=5,0.10-130X

Slidox

0x

Kps=[Ag+][Br-]=5,0.10-13 Kps=x=5,0.10-13 x=[Ag+]=5,0.10-13=7,07.10-7 mol/L 7,07.10-7mol Ag+ 1000mL y 1mL y=7,07.10-10 mol Ag+/mL

1 mol Ag+ 107,87g 7,07.10-10mol z

z= 7,63.10-8 g Ag+/mL7,63.10-8g Ag+ 10-9g

w=76ng/mL

w ng 1 ng

[Ag+]=76 ppb

AgI(s)Ag+(aq)+I-(aq)Incio SlidoFinal x

kps=8,3.10-17

0X

0x

Kps=[Ag+][I-]=8,3.10-17 Kps=x [Ag+]=x=8,3.10-17=9,11.10-9 mol/L 9,11.10-9 mol Ag+ 1000mL y 1mL y=9,11.10-12mol Ag+/mL

1 mol Ag+ 107,87g 9,11.10-12 mol z

z=9,83.10-10 g de Ag+/mL1g Ag+ 9,83.x10-10g 109 ng w

w=0,98ng de Ag+/mL[Ag+]=0,98 ppb

Cu4(OH)6(SO4)(s)4Cu2+(aq)+6OH-(aq)+SO42-(aq)IncioFinal

Slidox

04X

1,0.10-61,0.10-6

XX

Kps=[Cu2+]4.[OH-]6.[SO42-]=2,3.10-69 Kps=(4x)4.(1,0.10-6)6.x=2,3.10-69 256x5=2,3.10-33

x=9,79.10-8

[Cu2+]=4x=4.(9,79.10-8)=3,9.10-7M

a) solubilidade em gua destilada: CaSO4(s)Ca2+(aq)+SO42-(aq)

Incio Slido Final x

0 X

0 x

Kps=[Ca2+].[SO42-]=2,4.10-5 Kps=x.x x=2.4.10-5 x=S S=4,9.10-3M 4,9.10-3 mol/L y 1mol/L 136,14g y=0,67g/L S=0,67g/L

b) soluo de CaCl2 0,50M: CaSO4(s)Ca2+(aq)+SO42-(aq)

Incio Slido Final x

0,5 X+0,5

0 X

Kps=[Ca2+].[SO42-] Kps=(x+0,5).x Como x