9. Which of the following is TRUE concerning the EDTA back-titration method? a. The Zn/ Mg-EDTA complex should be less s

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9 Which Of The Following Is True Concerning The Edta Back Titration Method A The Zn Mg Edta Complex Should Be Less S 1 (97.24 KiB) Viewed 33 times

9. Which of the following is TRUE concerning the EDTA back-titration method? a. The Zn/ Mg-EDTA complex should be less stable than the analyte-EDTA complex b. In the back-titration method, an unmeasured excess of a solution consisting of a Zn/Mg-EDTA complex is added to the analyte solution c. The metal analyte will bind to EDTA liberating Zn2+ or Mg2+ ions d. All of the above are true 10. It was found that A coordinates to a metal in a 4:1 stoichiometry. Noting that A* has a basic property, what is, at the equivalence point the complex ion concentration metal ion concentrations a. K b. 404K; c. 256(04)*K d. 4(04)*KI e. None of the answers 11. A solution of 0.0500M Ca2+ and 0.00500M Mg2+ was titrated against EDTA at pH = 10 (K' for CaY2-= 1.75 x 100 and K's for MgY2-= 1.72 x 108). Which statement is NOT TRUE? a. The reaction of formation of the calcium complex ion occurs with lower tendency. b. In the titration curve of Mg2+, a smaller change of pM occurs around the equivalence point. C. Eriochrome black T indicator could be used for both titrations. d. The pCa is larger than pMg after the excess addition of the EDTA.