Question

Fill in the Blanks Now try predicting solubility with a salt that is not 1:1 in cation:anion. If 5.0 juL of 10HM magnesium nitrate is mixed with 5.0 pL of 10pM sodium phosphate, will magnesium phosphate precipitate? Be sure to write the equilibrium and equilibrium equation carefully. Ksp for magnesium phosphate is: 1e-25. (Recall that u is the symbol for micro). Q = 3.125e-27 Will magnesium phosphate precipitate? (yes/no) yes Hint Remember to include the 3cubed and 2squared in your Ksp calculation. If you leave out these numbers, Q-3e-27 and you draw the wrong conclusion! Answered -Incorrect FFullscreen

Answer 1

Answer:

Now, the total volume of solution is 10 u.mL and concentrations are [Mg(NO₃)₂] = 5uM and [Na₃PO₄] = 5uM (after mixing the solutions)

Hence, on dissolution of salts;

[Mg²⁺] = 5 uM and [PO₄^3-] = 5 uM

3Mg²⁺ + 2PO₄^3- <=> Mg₃(PO₄)₂

Hence, Q = [Mg²⁺]³[PO₄^3-]² = [5 x 10^-6]³ [5 x 10^-6]² = 3.125 x 10^-27

Here, Q < Ksp for magnesium phosphate and hence, magnesium phosphate will not precipitate.

For precipitation of Magnesium phosphate, the Q is need to be greater than Ksp.

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