In the qualitative analysis scheme, magnesium and nickelprecipitate from solution upon the addition of sodium hydroxide.Once separated from the remaining cations by filtration ordecanting, the solid mixture is acidified and warmed to dissolvemagnesium and nickel cations back into solution. Adding ammoniacreates a buffer solution. (Remember, HCl and NH3 makes for NH4+cation.) The buffered solution should just be basic (say, pH = 8).Adding sodium hydrogen phosphate (Na2HPO4) precipitates magnesiumas MgNH4PO4 (Ksp = 3 x 10-13).
a) Write the Ksp expression for the dissociation ofMgNH4PO4.
b) Calculate the molar solubility of the compound in purewater.
c) Calculate the [NH4+] in a pH of 8.
d) Calculate the molar solubility of MgNH4PO4 in a solution withpH of 8.
