DPP 04 Ionic Equilibrium JH Sir-4295

PAGE NO. # 1

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DPP No.# 55Solubility product

1. Write the equation for dissociation of following salts and determine their solubility in terms of Ksp

.(i) PbBr

2(ii) Hg

2CrO

4(iii) BaC

2O

4(iv) Fe(OH)

3

(v) Ag2CO

3(vi) Sb

2S

3(vii) AgCNS (viii) Ag

3PO

4

(ix) Li3Na

3(AlF

6)2

(x) Hg2I2

(xi) Ba3(PO

4)

2(xii) Ca

5(PO

4)

3F

(xiii) A3B

4(xiv) CaF

2(xv) Ag

2CrO

4

2. (i) Ksp

of AgCl is 1.8 × 10�10. The solubility of AgCl in pure water in moles/litre :(A) 1.34 × 10�5 (B) 4.24 × 10�5 (C) 1.8 × 10�5 (D) 3.6 × 10�5

(ii) In the above question the solubility in gram per litre will be �(A) 180.26 × 10�5 (B) 192.29 × 10�5 (C) 210 × 10�4 (D) 176.85 × 10�4

3. Calculate solubility of AB2 in pure water. K

sp of AB

2 = 25.6 × 10�8,

4. Solubility of a A2B salt in pure water is 2 × 10�5 moles in 100 ml. Calculate K

sp of salt.

5. Ksp

of AgBr is 4 × 10�13 and [Al+] is a solution is 1 × 10�6 m/l what is [Br�] in that solution.

6. If Ksp

of AgI is 8.5 × 10�17. The maximum amount of AgI which can be dissolved in 2500 ml of water will be �(A) 9.22 × 10�9 gm (B) 2.3 × 108 gm (C) 5.42 × 10�5 gm (D) 2.17 × 10�5 gm

7. The volume of water needed to dissolve 1 g of BaSO4(K

sp = 1.1 × 10�10) at 25ºC is �

(A) 820 litre (B) 410 litre (C) 205 litre (D) none of these

8. How many grams of CaC2O

4 will dissolve in distilled water to make one litre of saturated solution of it ?

(Ksp

of CaC2O

4 = 2.5 × 10�9 mol2 lit�2)

(A) 0.0064 gm (B) 0.1028 gm (C) 0.1280gm (D) 0.2056 gm

9. At 20ºC, the Ag+ ion concentration in a saturated solution Ag2CrO

4 is 1.5 × 10�4 mole/lit. At 20ºC, the

solubility product of Ag2CrO

4 could be �

(A) 3.37 × 10�12 (B) 1.68 × 10�10 (C) 1.68 × 10�12 (D) 1.12 × 10�10

10. In the system CaF2(s) Ca2+(ag) + 2F�

increasing the concentration of Ca2+ ions 4 times will cause the eq. concentration of F� ions to change to.............. times the initial value.(A) 4 (B) 1/2 (C) 2 (D) 1/4

11. Concentration of Ag+ ion in a saturated solution of Ag2CrO

4 is 5.4 × 10�6 g/litre when the salt is 50% dissociated.

Then solubility product of Ag2CrO

4 is �

(A) 7.03 × 10�17 (B) 6.25 × 10�23 (C) 1.72 × 10�23 (D) 2.15 × 10�24

12. (i) For an experiment Pb(OH)2 is taken , if salt is 80% dissociated & K

sp of Pb(OH)

2 is 8 × 10�6. Then solubility

of salt in moles/litre is �(A) 1.57 × 10�2 (B) 2 × 10�2 (C) 1.26 × 10�5 (D) 2.3 × 10�2

(ii) Considering the above question, what will be the solubility in gms/litre �(A) 3.32 (B) 3.65 (C) 3.05 (D) 3.79

PHYSICAL INORGANICCHEMISTRYDAILY PRACTICE PROBLEMS

D P PCOURSE NAME : UMANG (UP) DATE : 23.09.2013 to 28.09.2013 DPP NO. 55 & 57

TARGETJEE (ADVANCED) : 2014

PAGE NO. # 2



13. pH of a saturated solution of A(OH)3 is 10. Calculate K

sp of A(OH)

3 at 25ºC.

14. Solubility of As2S

3 is 7.38 mg in 10ml of water. Calculate K

sp of As

2S

3.

15. Ksp

of A3B

4 is 6.912 × 10�18. Calculate solubility of A

3B

4.

DPP No.# 561.(a) The solubility of A

2X is y mol dm 3 . Its solubility product is :

(A) 6 y4 (B) 64 y4 (C) 36 y5 (D) 4 y3

(b) The solubility of sparingly soluble electrolyte MmA

a in water is given by the expression :

(A) s =

am

amsp

am

K

(B) s =

am/1

amsp

am

K

(C) s =

am

masp

am

K

(D) s =

am/1

masp

am

K

2.(a) Three sparingly soluble salts M2X, MX and MX

3 have the solubility product are in the ratio of 4: 1 : 27. Their

solubilities will be in the order(A) MX

3 > MX > M

2 X (B) MX

3 > M

2X > MX (C) MX > MX

3 > M

2X (D) MX > M

2X > MX

3

(b) A particular saturated solution of silver chromate, Ag2CrO

4, has [Ag+]= 5×10�5 and [CrO

42�] = 4.4×10�4 M.

What is value of Ksp

for Ag2CrO

4 ?

(A) 1.1 × 10�12 . (B) 1.5 × 10�12 (C) 2 × 10�6 (D) 1 × 1012.

3.(a) If the solubility product of silver oxalate is 5 × 10�10, what will be the weight of Ag2C

2O

4 in 2.5 litres of a

saturated solution ? (Ag = 108, C = 12, O = 16).(A) 0.50 gm (B) 0.38 gm (C) 0.30 gm (D) 0.45 gm.

(b) A student wants to prepare a saturated solution of Ag+ ion . He has got three samples AgCl (Ksp

= 10 10),AgBr (K

sp = 1.6 × 10 13) and Ag

2CrO

4 (K

sp = 3.2 × 10 11) . Which of the above compound will be used by him

using minimum weight to prepare 1 lit. of saturated solution.(A) AgCl (B) AgBr (C) Ag

2 CrO

4(D) all the above .

4.(a) If the solubility of Ag2SO4 in 10�2 M Na2SO4 solution be 2 × 10�8 M then Ksp of Ag2SO4 will be:(A) 32 × 10�24 (B) 16 × 10�18 (C) 32 × 10�18 (D) 16 × 10�24

(b) The solubility of CaF2 in water at 1518ºC is 2 × 10�4 mole/litre. Calculate K

sp of CaF

2 and its solubility in 0.1M

NaF solution.(A) 3.5 × 108 mole/litre (B) 3.0 × 109 mole/litre. (C) 3.3 × 10�9 mole/litre (D) 4.0 × 107 mole/litre

5.(a) Calculate F� in a solution saturated with respect of both MgF2 and SrF

2.

Ksp

(MgF2) = 9.5 x 10-9, K

sp(SrF

2) = 4 x 10-9.

(A) 3 × 10�3 M. (B) 4 × 10�2 M. (C) 3.5 × 10�3 M (D) 1 × 10�3 M.

(b) A solution is saturated with respect to SrCO3 & SrF

2. The [CO

32] was found to be 1.2 x 103 M. The

concentration of F in the solution would be : Ksp

(SrCO3) = 10�9, K

sp(SrF

2) = 3 × 10�11.

(A) 3 x 103 M (B) 2 x 102 M (C) 6 x 102 M (D) 6 x 107 M

6. Calculate the solubility of AgCl (s) in

(a) pure water (b) 0.1 M NaCl (c) 0.01 M CaCl2 at 25º C .

Ksp

(AgCl) = 2.56 10 10. Comment on the influence of

[ Cl]

on the solubility of AgCl.

7. Find the solubility of CaF2 in 0.5 M solution of CaCl

2 and water. How many times in solubility in the second

case greater than in the first ? Ksp

(CaF2) = 3.2 × 10�11.

8. If you place the amounts given below in pure water, will all of the salt dissolve before equilibrium can beestablished, or will some salt remain undissolved ?(a) 4.96 mg of MgF

2 in 125 ml of pure water, K

sp = 3.2 x 10-8

(b) 3.9 mg of CaF2 in 100 ml of pure water, K

sp = 4 x 10-12

Also find the percentage saturation in each case.

PAGE NO. # 3



DPP No.# 57

Solubility in presence of common ion

1. Solubility product of AgCl is 1.8 × 10�10, then find out solubility of AgCl in(i) 0.1M NaCl

(A) 3.6 × 10�10 (B) 1.8 × 10�10 (C) 3.6 × 10�9 (D) 1.8 × 10�9

(ii) 0.2M AgNO3

(A) 3 × 10�10 (B) 0.36 × 10�10 (C) 9 × 10�10 (D) 2.6 × 10�10

(iii) 2M CaCl2

(A) 9 × 10�10 (B) 4.5 × 10�11 (C) 1.5 × 10�11 (D) 6 × 10�11

(iv) (iv) pure water.(A) 1.34 × 10�5 (B) 4.34 × 10�5 (C) 2.87 × 10�5 (D) 1.89 × 10�5

2. Ksp of PbCl2 is 4 ×10�15 calculate its solubility in :

(i) pure water

(ii) 0.2 M AlCl3 solution

(iii) 5 × 10�3 M Pb3(PO

4)

2 solution

(iv) 0.02 M NaCl solution

(v) 0.4 M Pb(NO3)

2 solution

3. The solubility of AgCl will be minimum in �(A) 0.01 M AgNO

3(B) pure water (C) 0.01 M CaCl

2(D) 0.1 M NaCl

4. The solubility product of AgCl is 4 × 10�10 at 298 K. The solubility of AgCl in 0.04 M CaCl2 will be�

(A) 2 × 10�5 M (B) 1 × 10�4 M (C) 5 × 10�9 M (D) 2.2 × 10�4 M

5. The molar solubility of PbI2 in 0.2 M Pb(NO

3)

2 solution in terms of solubility product, K

sp of PbI

2 is�

(A)

2/1sp

2.0

K

(B)

2/1sp

8.0

K

(C)

3/1sp

8.0

K

(D)

2/1sp

4.0

K

6. Ksp

of Zn(OH)2 is 4.5 × 10�17 then its solubility in a solution having pH = 10 will be �

(A) 4.5 × 10�10 (B) 1.4 × 10�10 (C) 6.7 × 10�10 (D) 7.6 × 10�10

7. Solubility of Mg(OH)2 having K

sp equal to 8.9 × 10�13, in a solution containing 500 ml of 0.2 M NH

4OH and 500

ml of 0.4 M Ca(OH)2 is �

(A) 3.4 × 10�19 (B) 55.63 × 10�13 (C) 2.34 × 10�9 (D) 8.34 × 10�13

8. Molar solubility of As2S

3 in 0.3 M Al

2S

3 solution in terms of solubility product K

sp of As

2S

3 is�

(A) 918.2

Ksp(B)

916.2

K3 sp

(C) 2.1

Ksp(D)

2.1

K3 sp

9. Ksp

of PbI2 is 8 × 10�12. A solution contains 2 × 10�3 M Pb+2 ions and 2 × 10�4 M I� ions. Predict ppt of PbI

2 will

form or not.

11. The precipitate of CaF2 (K

sp = 1.7 × 10�10) is obtained when equal volumes of the following are mixed�

(A) 10�4 Ca2+ + 10�4 M F� (B) 10�2 M Ca2+ + 10�3 M F�

(C) 10�5 M Ca2+ + 10�3 M F� (D) 10�3 M Ca2+ and 10�3 M F�

PAGE NO. # 4



12. To Ag2CrO

4 solution over its own precipitate, CrO

4�2 ions are added. This result in

(A) increase in Ag+ concentration (B) decrease in Ag+ concentration(C) increase in solubility product (D) None of these

13. What is the minimum concentration of SO4

2� required to precipitate BaSO4 in a solution containing

1 × 10�4 mole of Ba2+ ? Ksp

for BaSO4 = 4 × 10�10

(A) 4 × 10�10 M (B) 4 × 10�6 M (C) 2 × 10�7 M (D) 2 × 10�3 M

14. What would be the pH at which Fe(OH)2 begins to precipitate from a solution containing 0.009 M Fe+2 ions.

Ksp

of Fe(OH)2 is 1.8 × 10�15.

(A) 8.37 (B) 6.35 (C) 7.65 (D) 9.28

15. How many grams of CaBr2 (MM = 200) can be added to 250 ml of 0.01 M solution of silver nitrate to just start

the precipitation of silver bromide. Ksp

of AgBr is 5.0 × 10�13.

16. A solution contains 0.1 M Zn+2 ions and is saturated with H2S. Calculatee amount of HCl which should be

added in 500 ml of solution to prercipitate ZnS. Ksp

of ZnS = 13.5 × 10�23. K1 of H

2S = 10�7 and K

2 of

H2S = 1.5 × 10�14 concentration of H

2S in saturated solutin is 0.1N.

17. A solution has 0.02 M A+2 and 0.1M NH4OH calculate the concentration of NH

4Cl required to prevent the

formation of A(OH)2 in solution. K

sp of A(OH)

2 is 2 × 10�12 and K

b of NH

4OH is 10�5.

ANSWER KEYDPP No.# 55

2. (i) (A) (ii) (B) 3. Ksp

of AB2 = 25.6 × 10�8, A = 4 × 10�3 m/l 4. 3.2 ×10�11

5. Br�= 4 × 10�7 m/l 6. (C) 7. (B) 8. (A) 9. (C)10. (B) 11. (B) 12. (i) (A) (ii) (D) 13. 3.34 × 10�17 14. 26.24 × 10�12

15. 10�3 m/l

DPP No.# 56

1.(a) (D) (b) (B) 2.(a) (B) (b) (A) 3.(a) (B) (b) (B)4.(a) (B) (b) (C) 5.(a) (A) (b) (C)6. (a) 1.6 × 10 -5 mol/lit. (b) 2.56 × 10 -9

mol/lit. (c) 1.28 × 10�8 mol/lit.

7. 4 × 10�6 M, 2 × 10�4 M, 50 times.8. (a) Will dissolve, 32% saturation (b) will not dissolve, 100% saturation.

DPP No.# 57Solubility in presence of common ion

1. (i) (D) 1.8 × 10�9 (ii) (C) (iii) (B) (iv) (A)2. (i)10�5 M (ii) 1.11 × 10�14 M (iii) 2.58 ×10�7 M (iv) 10�11 M (v) 5 × 10�8 M3. (C) 4. (C) 5. (B) 6. (A) 7. (B) 8. (A) 9. Yes

11. (B) 12. (B) 13. (B) 14. (C) 15. 1.25 × 10�9 gm 16. 6.01 gm

17. 0.1 M

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DPP 04 Ionic Equilibrium JH Sir-4295