Question

*The generic metal hydroxide  M(OH)2  has  Ksp  = 3.65×10^-12.  (NOTE:  In this particular problem, because of the magnitude of the  Ksp and the stoichiometry of the compound, the contribution of   OH−  from water can be ignored.  However, this may not always be the case.)*

4a. What is the solubility of M(OH)2 in pure water?  

Express your answer with the appropriate units.

4b. What is the solubility of M(OH)2 in a 0.202 M solution of M(NO3)2?

Express your answer with the appropriate units.

Answer 1

[note: in case of pure water the initial concentration of M⁺² ion was 0 M but in case of 0.202 M solution of M(NO₃)₂ the initial concentration of M⁺² ion was 0.202 M because in 0.202 M solution of M(NO3)2 it dissociates and gives 0.202 M of M⁺² ion. So in the part(B) we take the initial concentration of M⁺² as 0.202 M when M(OH)2 dissociates.]

Answer 2