1) The average human body contains 5.70 L of blood with a Fe2+concentration of 2.60×10−5 M . If a person ingests 12.0 mL of 16.0mM NaCN, what percentage of iron(II) in the blood would besequestered by the cyanide ion? (When species combine to produce acoordination complex, the equilibrium constant for thereaction is called is the formation constant,Kf.

For example, the iron(II) ion, Fe2+, can combine with thecyanide ion, CN−, to form the complex [Fe(CN)6]4− according to theequation

Fe2+(aq)+6CN−(aq)⇌[Fe(CN)6]4−(aq)

where Kf=4.21×1045.)

2) Consider a solution that is 1.5×10−2 M in Ba2+and 1.9×10−2 Min Ca2+.

Ksp(BaSO4)=1.07×10−10
Ksp(CaSO4)=7.10×10−5
What minimum concentration of Na2SO4 is required to cause theprecipitation of the cation that precipitates first?

3) Calculate the solubility (in grams per 1.00×102mL ofsolution) of magnesium hydroxide in a solution buffered at pH =12.
Calculate the solubility (in grams per 1.00×102mL of solution) ofmagnesium hydroxide in pure water.
How does the solubility of Mg(OH)2 in a buffered solution compareto the solubility of Mg(OH)2 in pure water?

4) Use the appropriate values of Ksp and Kf to find theequilibrium constant for the following reaction:
FeS(s)+6CN−(aq)⇌Fe(CN)4−6(aq)+S2−(aq)

5) A 115.0 −mL sample of a solution that is 3.0×10−3M  in AgNO3  is mixed with a 225.0 −mL sampleof a solution that is 0.11 M in NaCN. A complex ion forms.After thesolution reaches equilibrium, what concentration of Ag+(aq)remains?