25.00 mL 0.01000 M Ni2+ is titrated with 0.01000 M EDTA in a solution buffered to pH 5.0. Given that the formation constant for the Ni-EDTA (NiY2– ) chelate is 4.2 x 1018 and the 4 value at pH 5.0 is 3.54 x 10–7 . Explain briefly why EDTA is an important reagent used in complexometric titrations.

25.00 mL 0.01000 M Ni2+ is titrated with 0.01000 M EDTA in a solution buffered to pH 5.0. Given that the formation constant for the Ni-EDTA (NiY2– ) chelate is 4.2 x 1018 and the 4 value at pH 5.0 is 3.54 x 10–7 . Explain briefly why EDTA is an important reagent used in complexometric titrations.

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter17: Complexation And Precipitation Reactions And Titrations

Section: Chapter Questions

Problem 17.31QAP

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25.00 mL 0.01000 M Ni2+ is titrated with 0.01000 M EDTA in a solution buffered to pH 5.0. Given that the formation constant for the Ni-EDTA (NiY2–) chelate is 4.2 x 1018 and the 4 value at pH 5.0 is 3.54 x 10–7. What is EDTA?
25.00 mL 0.01000 M Ni2+ is titrated with 0.01000 M EDTA in a solution buffered to pH 5.0. Given that the formation constant for the Ni-EDTA (NiY2–) chelate is 4.2 x 1018 and the 4 value at pH 5.0 is 3.54 x 10–7 An indicator (Ind) forms a metal-indicator complex with Ni2+ (NiInd), giving aconditional formation constant of 1.00 x 108 at pH 5.0. It is generally assumedthat human eyes can detect about 1 part of one color in 10 parts of another;therefore, the first discernible color change will occur when the [NiInd]:[Ind]ratio changes from 10 to about 0.1.
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