Question

14.

A)Solid zinc nitrate is slowly added to 75.0 mL of a 0.483 M ammonium phosphate solution until the concentration of zinc ion is 0.0422 M. The percent of phosphate ion remaining in solution is?

B)Solid potassium chloride is slowly added to 50.0 mL of a 0.321 M silver fluoride solution until the concentration of chloride ion is 0.0214 M. The mass of silver ion remaining in solution is?

Answer 1

14)

A)

Zn3(PO4)2   ----------------> 3 Zn2+ +   2 PO43-

Ksp = [Zn2+]^3 [PO43-]^2

9.1 x 10^-33 = (0.0422)^3 (PO43-)^2

[PO43-] = 1.10 x 10^-14

% of PO43- = 1.10 x 10^-14 / 0.483 ) x 100

                   = 2.28 x 10^-12

B)

AgCl   -------------->   Ag+   +    Cl-

Ksp = [Ag+][Cl-]

1.8 x 10^-10 = (Ag+)(0.0214)

[Ag+] = 8.41 x 10^-9 M

% of Ag+ ion = ( 8.41 x 10^-9 / 0.321) x 100

                    = 2.62 x 10^-6