Ammonium carbonate, (NH₄)₂CO₃ dissolves in water releasing the ammonium ion, NH₄⁺, and carbonate ion, CO₃^2- into solution. Both of these ions hydrolyze (react with water). The chemical equations describing the hydrolysis reactions are given. By adding these reactions one can write the overall balanced net ionic equation for the reaction that occurs when ammonium carbonate dissolves in water. Write the overall balanced net ionic equation, calculate the equilibrium constant, write the overall equilibrium expression, and calculate the carbonate ion concentration, [CO₃^2-], of a 1.0 mol/L solution of ammonium carbonate. (Hint: this requires solving a quadratic equation)

--Equations

(1) (NH₄)₂CO₃ (aq) --> 2NH₄⁺ + CO₃^2-

(2) NH₄⁺ + H₂O(l) <--> NH₃(aq) + H₃O⁺ K_a=5.6x10^-10

(3) CO₃^2- + H₂O(l) <--> HCO₃^- + OH^- K_b=2.1x10^-4

(4) Ca²⁺ + CO₃^2- <--> CaCO₃(s)