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Title: Calculate the concentration of OH- in Ca(OH)2 solution Post by: JLeopard on Aug 24, 2014 Calculate the concentration of OH- in Ca(OH)2 solution
the concentration of Ca(OH)2 is 3.0*10^-7 M the answer is 6.2*10^-7 M but I don't know the procedure please help me ! assume that the Ksp of Ca(OH)2 is 5.5×10^–6. Title: Re: Calculate the concentration of OH- in Ca(OH)2 solution Post by: GeoExp on Aug 25, 2014 I think you start with Ca(OH)2 → Ca2+ + 2OH–
Then you use this relationship, where pH is 12.10 pH = 14 - pOH. pOH = -log[OH-] I don't know :p Title: Re: Calculate the concentration of OH- in Ca(OH)2 solution Post by: zoeksyrianos on Aug 25, 2014 Here'a a similar question, but I'm not sure if it applies.
Similar question Calculate the theoretical [OH–] in a saturated Ca(OH)2 solution. Use a literature value of Ksp = 6.5x 10-6. Solution Ca(OH)2 <-----> Ca+2 + 2 OH- We know that the Ksp = [Ca+2]([OH-]^2). We know that the concentration of the Ca will be half the concentration of the OH in the equilibrium. [Ca] = x, [OH-] = 2x 6.5*10^-6 = x * 4x^2 6.5*10^-6 = 4x^3 1.625*10^-6 = x^3 x = .012 M [OH-] = 2x = .024 M ANSWER: Theoretical [OH-] = .024 M Title: Re: Calculate the concentration of OH- in Ca(OH)2 solution Post by: JLeopard on Aug 26, 2014 don't we need to consider the initial concentration of Ca(OH)2 ?
And 1.0*10^-7 M OH- dissociate from water |