pH question about insoluble salts.?

Question

How do you calculate the pH of a solution at saturation when given the insoluble salt and its Ksp?

Answer 1

If the salt was from nutralization of a strong acid and a strong base, the pH is nutrial no matter what is Ksp.
However, if the salt was from nutralization of either a weak acid and a strong base, or a strong acid with a weak base, or even both a weak acid and a weak base, the pH is to be calculated with both Ksp and Ka, and/ or Kb.
Let us take a weak acid and a strong base for example. Let X M be the concentration of M+ dissolved. Let Y M be the OH- concentration [OH-]. We have:
MA(s) <==> M+(aq) + A-(aq)
-------------------X---------(X-Y)
HA(aq) + OH-<==>H2O + A-(aq)
Y-------------Y------------------(X-Y)
From the definition of Ksp and Ka, we then have:
Ksp = [M+]*[A-] = X(X-Y)
Ka/Kw = { [H+]*[A-]/[HA] }/ { [H+]*[OH-] }
= [A-]/ { [HA]*[OH-] } = (X - Y)/Y^2
where Kw is the water self dissociation constant 10^-14 M^2.
So you have 2-variable 2 simultaneous equations. Solve the equations you will get Y the concentration [OH-]. Finally,
pH = 14 + log [OH-]

Answer 2

i'm making all-organic cleansing soap-scum cleaners with lemons and limes. i do no longer pick my 5-gallon batches to flow undesirable, so i had to function 20% table salt to maintain it and shop the citric in it from going undesirable, yet i do no longer pick to diminish the ph; the hi ph is what cuts the cleansing soap-scum. Will the salt decrease the PH in my vinegar & citrus answer?