Ion Concentration Problems

Question

Determine the concentration of each ion in .50 M solutions:

a.) Magnesium Acetate

b.) Barium Hydroxide

c.) Iron (III) Nitrate

Answer 1

a) Magnesium acetate = Mg(C₂H₃O₂)₂

Mg(C₂H₃O₂)₂ ==> Mg2+ + 2C₂H₃O₂^-

0.050 M Mg(C₂H₃O₂)₂ ==> 0.050 M Mg²⁺ + 2 x 0.050 M C₂H₃O₂^-

Concentration of Mg2+ = 0.050 M

Concentration of C₂H₃O₂^- (acetate ion) = 0.10 M

b) Barium hydroxide = Ba(OH)₂

Ba(OH)₂ ==> Ba²⁺ + 2OH^-

Concentration of Ba²⁺ = 0.05 M

Concentration of OH^- = 2 x 0.05 M = 0.10 M

c) Iron(III) nitrate = Fe(NO₃)₃

Fe(NO₃)₃ ==> Fe³⁺ + 3NO₃^-

Concentration of Fe³⁺ = 0.05 M

Concentration of NO₃^- = 3 x 0.05 M = 0.15 M