3. Using an Excel spreadsheet, develop a graphical plot showing a solubility dia
ID: 554661 • Letter: 3
Question
3. Using an Excel spreadsheet, develop a graphical plot showing a solubility diagram as a function of solution pH for Cu considering the formation of the copper hydroxide solid Cu(OH)2 (s) (Ksp-10-153). Answer the following questions: a) At an aqueous concentration of Cu of Ix103 M, would you expect Cu(OH2(s) precipitation at pH 6? precipitation at pH 9? precipitation at pH 10? b) At an aqueous concentration of Cu of1x1025 M, would you expect Cu(OH)2(s) c) At an aqueous concentration of Cu of 1x102 M, would you expect Cu(OH2(s)Explanation / Answer
As we know, [Mn+ ] [OH-] > Ksp (Precipitation occurs)
(a) In the first case, [Mn+ ] or [Cu2+ ]=10-5 M and at pH 6, [H+]=10-6 M, so [OH-]=10-8
so, [Cu+ ] [OH-]=10-13 which is >10-19.3
so, precipitation occurs
(b) [Cu2+ ]=10-2.5 M and at pH 9, [H+]=10-9 M, so [OH-]=10-5
so,[Cu+ ] [OH-]=10-7.5 which is >10-19.3,
so, precipitation occurs
(c) [Cu2+ ]=10-2 M and at pH 10, [H+]=10-10 M, so [OH-]=10-4
so,[Cu+ ] [OH-]=10-6 which is >10-19.3,
so, precipitation occurs