Solubility Product Practice Answers

Solubility Practice Questions Answers

 

1.

PbF2 Pb2+ + 2F C = n/v

2.15clip_image002[2]10-3 2.15clip_image002[3]10-3 4.3clip_image002[4]10-3 C = 2.15clip_image002[5]10-3 mol

1L

Ksp = [Pb2+][F]2 C = 2.15clip_image002[6]10-3 mol/L

Ksp = (2.15clip_image002[7]10-3)(4.3clip_image002[8]10-3)2

Ksp = 3.98clip_image002[9]10-8

2.

CoCo3 Co2+ + CO32- Na2CO3 2Na+ + CO3

1clip_image002[10]10-9 1clip_image002[11]10-9 1clip_image002[12]10-9 0.1 0.2 0.1

Ksp = [Co2+][Co32-]

Ksp = (1clip_image002[13]10-9)(1clip_image002[14]10-9 + 0.1)

Ksp = 1clip_image002[15]10-10

3.

PbF2 Pb2+ + 2F Pb(NO3) Pb2+ + 2NO3

3.1clip_image002[16]10-4 3.1clip_image002[17]10-4 6.2clip_image002[18]10-4 0.1 0.1 0.2

Ksp = [Pb2+][F]2

Ksp = (3.1clip_image002[19]10-4 + 0.10)(6.2clip_image002[20]10-4)2

Ksp = 3.86clip_image002[21]10-8

4.

Ksp = 5.0clip_image002[22]10-13 AgBr Ag+ + Br

x x x

Ksp = [Ag+][Br ]

5.0clip_image002[23]10-13 = x2

x = 7.07clip_image002[24]10-7

∴ Molar solubility = 7.07clip_image002[25]10-7

5.

Ag2CO3 2Ag+ + CO3 Ksp = 8.1clip_image002[26]10-12

2x x

Ksp = [Ag+]2 [CO3 ]

8.1clip_image002[27]10-12 = 4x3

x3 = 2.015clip_image002[28]10-12

x = 1.3clip_image002[29]10-4

∴ Molar solubility is 1.3clip_image002[30]10-4

6.

AgI Ag+ + I NaI Na+ + I

x x x 0.2 0.2

Ksp = [Ag+][ I ]

8.3clip_image002[31]10-17 = (x)(x + 0.2) Negligible because Ksp is so small

x = 4.15clip_image002[32]10-16

∴ Molar solubility is 4.15clip_image002[33]10-16

7.

Fe(OH)3 Fe3+ + 3OH OH = 0.05

x x 3x

Ksp = [Fe3+][ OH ]3

1.6clip_image002[34]10-39 = (x)(3x + 0.05)3 Negligible because Ksp is so small

x = 1.28clip_image002[35]10-35

∴ Molar solubility is 1.28clip_image002[36]10-35

8.

Trial Ksp = [Ca][SO4 ]

Trial Ksp = (0.0025)(0.03)

Trial Ksp = 7.5clip_image002[37]10-5 Ksp = 2.4clip_image002[38]10-5

∵ Trial Ksp > Ksp

∴ Precipitate will form

9.

Ksp = [Ag+]2 [CrO4 -2 ] Ag2CrO4 2Ag+ + CrO42-

Trial Ksp = (4.8clip_image00710-5 )2 (3.4clip_image002[39]10-4 )

Trial Ksp = 7.83clip_image002[40]10-13

∵ Trial Ksp < Ksp

∴ No precipitate will form

10.

Pb(NO3)2 Pb+2 + 2NO3MgSO4 Mg2+ + SO4 2 –

C1V1 = C2V2 C1V1 = C2V2

(1.0clip_image002[41]10-3 )(100) = C2 (200) (2.0clip_image002[42]10-3 )(100) = C2 (200)

C2 = 5.0clip_image002[43]10-4 C2 = 1clip_image002[44]10-3

PbSO4 Pb+ + SO42-

Trial Ksp = [Pb2+][SO42 – ] Ksp = 6.3clip_image002[45]10-7

Trial Ksp = (5.0clip_image002[46]10-4)(1clip_image002[47]10-3)

Trial Ksp = 5clip_image002[48]10-7

∵ Trial Ksp < Ksp

∴ No precipitate will form