The concentration of Mg2+ in seawater is 0.052 M. At what pH will 76% of the Mg2+ be precipitated as the hydroxide salt? [Ksp for Mg(OH)2 = 8.9 ✕ 10-12.]

At pH 4.85 , 76% of will be precipitated as the hydroxide salt.

Explanation:

When 76% of has precipitated out , 24% remains out.

Given= Ksp for

(Here , ksp is the molar solubility )

Now ,

             =

We , know the formula to find out the ksp ,

Given formula is -

Now , putting the given values ,

Now , calculating the pH,

( where Kw is the ionic product of the water)

         = 4.85

Therefore , the pH to be precipitated is 4.85