384
Solubility Product and Precipitation
salt from the buffer to significantly change the [base]/[salt] ratio, and the pH
will remain essentially unchanged. In the two preceding problems, it is easily
shown that the pH of the final solutions is 8.88.
PROBLEMS A
1. The following solubilities have been determined by experiment. From these
experimental data, calculate the solubility products for the solids involved.
The solubilities are given in grams/100 ml of solution.
(a) Agl, 2.14 x 10~
7
(e) Ag 3 PO 4 , 2.01 x 10~
3
(b) BaSO 4 , 2.41 x lO'
4
(f) PbS, 1.20 x 1Q-'
2
(c) Cd(OH) 2 , 1.46 x 104
(g) BaCO 3 , 4.63 x 10~
4
(d) SrF 2 , 1.07 x 1Q2
(h) Sb 2 S 3 , 3.63 x lO'
18
2. Which of the following solids will dissolve readily in an excess of 1.00 M HC1?
(a) Agl
(d) Zn(OH) 2
(b) MnCO 3
(e) SrSO 4
(c) SrCrO 4
(f) BaC 2 O 4
3. In each of the following cases, show whether a precipitate will form under the
given conditions.
(a) 1.00 ml of 0.100 M AgNO 3 is added to 1 liter of 0.0100 M Na 2 SO 4
(b) 1.00 g of Pb(NO 3 ) 2 is added to 100 ml of 0.0100 M HC1
(c) 1.00 ml of 1.00 M NaOH is added to 1 liter of 1.00 x 10~
4 M Mg(N0 3 ) 2
(d) 1.00 ml of 1.00 M NH 3 is added to 1 liter of 1.00 x 10~
4 M Mg(NO 3 ) 2
(e) 1.00 ml of 0.100 M Sr(NO 3 ) 2 is added to 1 liter of 0.0100 M HF
(f) 1.00 ml of 0.0100 M Ba(NO 3 ) 2 is added to 1 liter of 0.100 M NaHC 2 O 4
(g) 1.00 mg of CaCl 2 and 1.00 mg of Na 2 C 2 O 4 are added to 100 ml of H 2 0
4. Calculate the solubility (in moles/liter) of each of the following compounds in
water (neglect hydrolysis effects).
(a) HgS
(d) Ag 2 S
(b) SrCrO 4
(e) PbI 2
(c) CaC 2 O 4
(f) Zn(OH) 2
5. Calculate how many grams of CaC 2 O 4 will dissolve in 1.00 liter of (a) water,
(b) 0.100 M Na-ACv (c) 0.0100 M CaCl 2 , (d) 0.100 M NaNO 3 .
6. Calculate how many grams of PbI 2 will dissolve in 250 ml of (a) water, (b)
0.0100 M Pb(NO 3 ) 2 , (c) 0.0100 M CaI 2 .
7. What concentration of sulfide ion is needed to commence precipitation of each
of the following metals from solution as the sulfide'
7
(a) 0.100 M CuCl 2
(d) 1.00 x 10~
3 M Bi(NO 3 ) 3
(b) 1.00 x 10-" M AgNO 3
(e) 1.00 x lO'
6 M Hg(NO 3 ) 2
(c) 0.0200 M T1NO 3
8. What OH~ concentration is needed to commence precipitation of each of the
following metals as the hydroxide, if each is present to the extent of 1.00 mgof
metal ion/milliliter?
Solubility Product and Precipitation
salt from the buffer to significantly change the [base]/[salt] ratio, and the pH
will remain essentially unchanged. In the two preceding problems, it is easily
shown that the pH of the final solutions is 8.88.
PROBLEMS A
1. The following solubilities have been determined by experiment. From these
experimental data, calculate the solubility products for the solids involved.
The solubilities are given in grams/100 ml of solution.
(a) Agl, 2.14 x 10~
7
(e) Ag 3 PO 4 , 2.01 x 10~
3
(b) BaSO 4 , 2.41 x lO'
4
(f) PbS, 1.20 x 1Q-'
2
(c) Cd(OH) 2 , 1.46 x 104
(g) BaCO 3 , 4.63 x 10~
4
(d) SrF 2 , 1.07 x 1Q2
(h) Sb 2 S 3 , 3.63 x lO'
18
2. Which of the following solids will dissolve readily in an excess of 1.00 M HC1?
(a) Agl
(d) Zn(OH) 2
(b) MnCO 3
(e) SrSO 4
(c) SrCrO 4
(f) BaC 2 O 4
3. In each of the following cases, show whether a precipitate will form under the
given conditions.
(a) 1.00 ml of 0.100 M AgNO 3 is added to 1 liter of 0.0100 M Na 2 SO 4
(b) 1.00 g of Pb(NO 3 ) 2 is added to 100 ml of 0.0100 M HC1
(c) 1.00 ml of 1.00 M NaOH is added to 1 liter of 1.00 x 10~
4 M Mg(N0 3 ) 2
(d) 1.00 ml of 1.00 M NH 3 is added to 1 liter of 1.00 x 10~
4 M Mg(NO 3 ) 2
(e) 1.00 ml of 0.100 M Sr(NO 3 ) 2 is added to 1 liter of 0.0100 M HF
(f) 1.00 ml of 0.0100 M Ba(NO 3 ) 2 is added to 1 liter of 0.100 M NaHC 2 O 4
(g) 1.00 mg of CaCl 2 and 1.00 mg of Na 2 C 2 O 4 are added to 100 ml of H 2 0
4. Calculate the solubility (in moles/liter) of each of the following compounds in
water (neglect hydrolysis effects).
(a) HgS
(d) Ag 2 S
(b) SrCrO 4
(e) PbI 2
(c) CaC 2 O 4
(f) Zn(OH) 2
5. Calculate how many grams of CaC 2 O 4 will dissolve in 1.00 liter of (a) water,
(b) 0.100 M Na-ACv (c) 0.0100 M CaCl 2 , (d) 0.100 M NaNO 3 .
6. Calculate how many grams of PbI 2 will dissolve in 250 ml of (a) water, (b)
0.0100 M Pb(NO 3 ) 2 , (c) 0.0100 M CaI 2 .
7. What concentration of sulfide ion is needed to commence precipitation of each
of the following metals from solution as the sulfide'
7
(a) 0.100 M CuCl 2
(d) 1.00 x 10~
3 M Bi(NO 3 ) 3
(b) 1.00 x 10-" M AgNO 3
(e) 1.00 x lO'
6 M Hg(NO 3 ) 2
(c) 0.0200 M T1NO 3
8. What OH~ concentration is needed to commence precipitation of each of the
following metals as the hydroxide, if each is present to the extent of 1.00 mgof
metal ion/milliliter?