In which of these situations is it necessary to perform an EDTA back titration instead of a direct titration? The analyte precipitates in the absence of EDTA. The formation constant of the metal-EDTA complex is small. The analyte blocks the indicator. The color of the free indicator and metal-indicator complex are too similar.

In which of these situations is it necessary to perform an EDTA back titration instead of a direct titration? The analyte precipitates in the absence of EDTA. The formation constant of the metal-EDTA complex is small. The analyte blocks the indicator. The color of the free indicator and metal-indicator complex are too similar.

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter17: Complexation And Precipitation Reactions And Titrations

Section: Chapter Questions

Problem 17.3QAP

See similar textbooks

Similar questions

Which of the following causes the sharpest change in the equivalence point of a complexometric titration? a) Increasing the concentration of the EDTA solution b) Decreased concentration of the analyte c) increase the stability of the [metal-EDTA] complex
The titration of Zn+2 and EDTA is carried out in the same manner as the Mg+2-EDTA titration. In this case, the ammonia in the EDTA buffer serves an additional purpose, what is it?
Which of the following causes the sharpest change in the equivalence point of a complexometric titration? A. Increasing the concentration of the EDTA solution B. Decreased concentration of the analyte C. Increasing the concentration of the EDTA solution D. Increasing the stability of the [metal-EDTA] complex
An auxiliary competing agent is used in EDTA titrations to slow down the titration. keep some interfering component of the analyte mixture from complexing with the EDTA. speed up the titration. keep the metal ion from precipitating out of the solution.
In compleximetric titration, why should the conditional formation constant between the indicator and the metal have a smaller value than the conditional formation constant between the titrant and the same metal ion?
The titration of Zn+2 and EDTA is carried out in the same manner as Mg2+ - EDTA titration (in fact, Zn metal may be used to standardize your EDTA solution). In this case, the ammonia from the pH 10 buffer serves and additional purpose other than the deprotonation of EDTA. What is it? pH 10 buffer is made with 57 mL of concetrated NH3 (or NH4OH) and 7 g of NH4Cl and diluted to 100 mL with DI water
Which of the following statements is false? EDTA acts as a Lewis base while the metal analyte acts as a Lewis acid during titration pH must not exceed 10 because the analyte may form its hydroxide which will form a precipitate The Kf of EDTA analyte complex must be larger than the EDTA indicator complex The smaller the Kf the larger the sharpness of the end point of the titration curve
In order to adjust the EDTA solution, 10 mL of 0.01M Ca + 2 sample was taken and 10 mL of pH 10 buffer was added on it and it was completed to 100 mL. Then, two drops of EBT indicator were added and titrated with EDTA. Since the consumption is 13 mL, what is the concentration of EDTA solution in terms of molarity?
Question:- We performed a titration with EDTA to determine the presence of Calcium in a limestone sample. We used a calcium carbonate standard to standardize the EDTA. Calmagite was used as the indicator and 1.5 g of MgCl2 was added to the EDTA to allow the indicator to function. Wouldn't this addition of magnesium to the titrant cause the end point volume to be too high? Please explain.
Which of the following statement regarding EDTA titration is incorrect A. In indirect titration, the analyte can not be titrated against EDTA B. In normal direct titration, the color of the endpoint is from the metal-indicator complex C. In back titration, excess EDTA is titrated with another standard solution of a second metal ion D. In masking titration, the sample or the interference can be isolated by "masking"
Your titration experiment included phosphoric acid, liqid starch, and Iodine-Potassium-Iodide (IKI) solution. The following information is given: iodine is too weakly colored to act as an effective primary indicator, but it is enhanced by its interaction with stach in a solution. The secondary indicator you will use in this experiment is iodine-starch complex. Iodine-potassium-iodide is the titrant. What acted as the primary indicator in this experiment? The secondary indicator? What was the role of the phosphoric acid? What would happen if you forgot to add it, or added a base instead?
Which of the following statement regarding EDTA titration is incorrect In back titration, excess EDTA is titrated with another standard solution of a second metal ion In normal direct titration, the color of the endpoint is from the metal-indicator complex In indirect titration, the analyte can not be titrated against EDTA In masking titration, the sample or the interference can be isolated by "masking"