only need part d 12 1012 For a solution in which 80 10 cal

only need part d

12 10-12. For a solution in which 8.0 × 10 , cal K for \"(a) AgSCN. (b) Pbl, \"(c) La(IO3)3. (d) MeNH PO

Solution

µ = molar solubility = 8.0 x 10^-2 moles/litre

When MgNH₄PO₄ dissolves, it dissociates like this:

MgNH₄PO₄ ---> Mg²⁺ + NH₄PO₄^2-

The K_sp expression is:

K_sp = [Mg²⁺] [NH₄PO₄^2-]

There is a 1:1 molar ratio between the MgNH₄PO₄ that dissolves and Mg²⁺ that is in solution. Same way there is a 1:1 molar ratio between dissolved MgNH₄PO₄ and NH₄PO₄^2- in solution.This means, when 8.0 x10^-2 moles/litre of MgNH₄PO₄ dissolves, it produces 8.0 x10^-2 mole per liter of Mg²⁺ and 8.0 x10^-2 mole per liter of NH₄PO₄^2- in solution.

Putting the values into the K_sp expression :

K_sp = (8.0 x10^-2) (8.0 x10^-2) = 64.0 x 10^-2 = 0.64