Assignment:
In forming a chelate with a metal ion, a mixture of free EDTA (abbreviated Y^4-) and metal chelate (abbreviated MY^n-4) can buffer the free metal ion concentration at values near the dissociation constant of the metal chelate, just as a weak acid and a salt can buffer the hydrogen ion concentration at values near the acid dissociation constant.
This equilibrium is governed by the equation
Where Kf is the association constant of the metal and Y^4-, αy^4- is the fraction of EDTA in the Y^4- form, and [EDTA] is the total concentration of free (unbound) EDTA. is the "conditional formation constant."
How many grams of Na_2EDTA·2H_2O (FM 372.23) should be added to 1.51 g of Mg(NO_3)_2·2H_2O (FM 184.35) in a 500-mL volumetric flask to give a buffer with pMg^2+ = 8.00 at pH 10.00?
(log K_f for Mg-EDTA is 8.79 and αy^4- at pH 10.00 is 0.30.)
Mass Na_2EDTA*H_2O = _________________g
Provide complete and step by step solution for the question and show calculations and use formulas.