Example 2
Ba2+(aq) +EDTA+(aq)
Ba(EDTA)2(aq)
K = 7.7 × 107
The polyatomic ion C10H12N2O84 is commonly abbreviated as EDTA4. The ion can form
complexes with metal ions in aqueous solutions. A complex of EDTA4 with Ba2+ ions forms
according to the equation above. A 50.0 mL volume of a solution that has an EDTA+(aq)
concentration of 0.30 M is mixed with 50.0 mL of 0.20 M Ba(NO3)2 to produce 100.0 mL of
solution.
Considering the value of K for the reaction, determine the concentration of Ba(EDTA)2(aq)
in the 100.0 mL of solution. Justify your answer.