1. The K sp of copper (II) hydroxide is 4.8 x 10-20. What is the molar solubilit

Question

1. The Ksp of copper (II) hydroxide is 4.8 x 10-20. What is the molar solubility of Cu(OH)2?

2. Sodium hydroxide is soluble in water according to the following reaction: NaOH (s) Na+ (aq) + OH- (aq)
What is the molar solubility of Cu(OH)2 in a solution of 0.036 M NaOH?

3. What is the ionic strength of the above solution saturated with Cu(OH)2 at equilibrium?

4. What is the activity coefficient of the copper ion in the above solution saturated with Cu(OH)2?

This is all the same problem I just broke it up so you can read it easier.

Explanation / Answer

(1) Ksp = 4.8 x 10^-20

     Cu(OH)2 --------------------------> Cu+2   + 2 OH-

                                                         S             2S

Ksp = [Cu+2][OH-]^2

4.8 x 10^-20 = (S) (2S)^2

4.8 x 10^-20 = 4 S^3

S = 2.29 x 10^-7 M

molar solubility of Cu(OH)2 = 2.29 x 10^-7 M

(2)

NaOH ---------------------> Na+ + OH-

0.036M                                    0.036M

Cu(OH)2 --------------------------> Cu+2   + 2 OH-

                                                         S             2S+0.036 = 0.036

Ksp = [Cu+2][OH-]^2

4.8 x 10^-20 = (S) (0.036)^2

S = 3.7 x 10^-17 M

molar solubility in presence of NaOH = 3.7 x 10^-17 M

(3)

ionic strength = 1/2 [M1Z1^2 + M2Z^2]

                       = 1/2 [2.29x 10^-7 x 2^2 + 4.58 x 10^-7 x 1^1]

                       = 6.87 x 10^-7

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.