The following data were obtained from the spectrophotometric titration of Cu(II) and Ca(II) in an unknown solution. A 25.00 mL aliquot of the unknown was taken to which 50.0 mL of ethanolamine buffer and 25.0 mL of distilled water were added. The solution was then titrated with standard 0.2508 M EDTA solution. Plot the recorded data, absorbance against volume of EDTA in mL. Correct the absorbance for volume changes. Calculate the number of moles of Ca(II) and Cu(II) in the unknown sample. Vol of Titrant, mL Vol of Titrant, mL Abs Abs

The following data were obtained from the spectrophotometric titration of Cu(II) and Ca(II) in an unknown solution. A 25.00 mL aliquot of the unknown was taken to which 50.0 mL of ethanolamine buffer and 25.0 mL of distilled water were added. The solution was then titrated with standard 0.2508 M EDTA solution. Plot the recorded data, absorbance against volume of EDTA in mL. Correct the absorbance for volume changes. Calculate the number of moles of Ca(II) and Cu(II) in the unknown sample. Vol of Titrant, mL Vol of Titrant, mL Abs Abs

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

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A 50.00 ml aliquot of a solution containing Ca2+ and Mg2+ was buffered at pH 10 and titrated with 0.0418 M EDTA. The endpoint volume was 44.36 ml. A second aliquot of the same mixture was made strongly basic by the addition of NaOH – this causes the Mg2+ to precipitate as Mg(OH)2. The solution was then titrated with the 0.0418 M EDTA and the endpoint volume was found to be 30.02 ml. Calculate the molar concentration of Mg.
[Standardization] A 0.3045 g of CaCO3 primary standard was dissolved using concentrated HCl, evaporated to incipient dryness, and quantitatively transferred to a 250 mL volumetric flask and diluted to mark. A 10 mL of aliquot was then transferred to an Erlenmeyer flask, together with 5mL buffer and 5 drops of EBT indicator, and was used to standardize the EDTA titrant. The solution turned blue after the addition of 24.10 mL of EDTA. A blank correction was made and was determined to be 0.4 mL. [Analysis] A 30 mL unknown water sample was treated with 37.6 mL of EDTA. A blank correction was made and was determined to be 0.4 mL. What is the concentration of CaCO3 of the unknown water sample in ppm? (MW CaCO3 = 100.0869 g/mol)?
A 1.000 mL aliquot of a solution containing Cu²+ and Ni²+ is treated with 25.00 mL of a 0.04333 M EDTA solution. The solution is then back titrated with 0.02071 M Zn²+ solution at a pH of 5. A volume of 20.01 mL of the Zn²+ solution was needed to reach the xylenol orange end point. A 2.000 mL aliquot of the Cu²+ and Ni²+ solution is fed through an ion-exchange column that retains Ni²+. The Cu²+ that passed through the column is treated with 25.00 mL of 0.04333 M EDTA. This solution required 18.20 mL of 0.02071 M Zn²+ for back titration. The Ni²+ extracted from the column was treated witn 25.00 mL of 0.04333 M EDTA. How many milliliters of 0.02071 M Zn²+ is required for the back titration of the Ni²+ solution? volume: mL
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A 0.6006-g sample of Ni/Cu condenser tubing was dissolved in acid and diluted to 100 mL in a volumetric flask. Titration of both ions in a 25.0ml aliquot of this solution required 45.81 mL of 0.052285M EDTA. Mercaptoacetic acid and NH3 were then introduced; production of the Cu complex with the former resulted in the release of an equivalent amount of EDTA, which required 22.85ml titration with 0.07238M Mg2+. Calculate the %Ni (59.693 g/mol) in the alloy.
The un-ionized form of the weak acid HA does not absorb in the visible region. When it ionizes, its conjugate base (A-) absorbs light strongly at 510 nm. The following data were obtained by measuring the absorbance at 510 nm of solutions with a concen- tration of 1.0 x 104 M HA in different pH buffers. pH Absorbance 2.0 0.00 3.0 0.00 4.0 0.00 5.0 0.025 6.0 0.180 7.0 0.480 8.0 0.570 9.0 0.595 10.0 0.595 11.0 0.595 12.0 0.595 What is the approximate pK of HA?
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