3.4Molar absorptivity data for the cobalt and nickel complexes with 2,3-quinoxalinedithiol areEco=36,400 and EN=5520 at 510 nm and Eco-1240 and EN=17,500 at 656 nm. A 0.425 gsample was dissolved and diluted to 50.0 mL. A 25.0 mL aliquot was treated to eliminateinterferences, after addition of 2,3-quinoxalinedithiol, the volume was adjusted to 50.0mL. This solution had an absorbance of 0.446 at 510 nm and 0.326 at 656 nm in a 1.00cm cell. Calculate the concentration (parts per million) of Co and Ni in the sample.

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lar absorptivity data for the cobalt and nickel complexes with 2,3-quinoxalinedithiol are =36,400 and EN=5520 at 510 nm and Eco-1240 and EN=17,500 at 656 nm. A 0.425 g mple was dissolved and diluted to 50.0 mL. A 25.0 mL aliquot was treated to eliminate erferences, after addition of 2,3-quinoxalined ithiol, the volume was adjusted to 50.0 . This solution had an absorbance of 0.446 at 510 nm and 0.326 at 656 nm in a 1.00 cell. Calculate the concentration (parts per million) of Co and Ni in the sample.

lar absorptivity data for the cobalt and nickel complexes with 2,3-quinoxalinedithiol are =36,400 and EN=5520 at 510 nm and Eco-1240 and EN=17,500 at 656 nm. A 0.425 g mple was dissolved and diluted to 50.0 mL. A 25.0 mL aliquot was treated to eliminate erferences, after addition of 2,3-quinoxalined ithiol, the volume was adjusted to 50.0 . This solution had an absorbance of 0.446 at 510 nm and 0.326 at 656 nm in a 1.00 cell. Calculate the concentration (parts per million) of Co and Ni in the sample.

Principles of Instrumental Analysis

7th Edition

ISBN:9781305577213

Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Chapter13: An Introduction To Ultraviolet-visible Molecular Absorption Spectrometry

Section: Chapter Questions

Problem 13.10QAP: Zinc(II) and the ligand L form a 1:1 complex that absorbs strongly at 600 nm. As long as the molar...

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The accompanying data (1.00-cm cells) were obtained for the spectrophotometric titration 10.00 mL of Pd(II) with 2.44 10-4 M Nitroso R(O. W Rollins and M. M. Oldham, Anal. chem .,1971, 43, 262, DOI: 10.1021/ac60297a026). Calculate the concentration of the Pd(II) solution, given that the ligand-to-cation ratio in the colored product is 2:1
Zinc(II) and the ligand L form a 1:1 complex that absorbs strongly at 600 nm. As long as the molar concentration of L exceeds that of zinc(II) by a factor of 5, the absorbance depends only on the cation concentration. Neither zinc(II) nor L absorbs at 600 nm. A solution that is 1.59 10-4 M in zinc(II) and 1.00 10-3 M in L has an absorbance of 0.352 in a 1.00-cm cell at 600 nm. Calculate (a) the percent transmittance of this solution. (b) the percent transmittance of this solution in a 2.50-cm cell. (c) the molar absorptivity of the complex.
At 580 nm, which is the wavelength of its maximum absorption, the complex Fe(SCN)2+ has a molar absorptivity of 7.00 I03L cm-1 mol-1.Calculate (a) the absorbance of a 4.47 10-5 M solution of the complex at 580 nm in a 1.00-cm cell. (b) the absorbance of a solution in a 2.50-cm cell in which the concentration of the complex is one half that in(a). (c) the percent transmittance of the solutions described in (a) and (b). (d) the absorbance of a solution that has half the transmittance of that described in (a).
Molar absorptivity data for the cobalt and nickel complexes with 2,3-quinoxalinedithiol are εCo = 36400 and εNi = 5520 at 510 nm and εCo = 1240 and ε Ni = 17500 at 656 nm. A 0.361-g sample was dissolved and diluted to 150.0 mL. A 25.0-mL aliquot was treated to eliminate interferences; after addition of 2,3-quinoxalinedithiol, the volume was adjusted to 50.0 mL. This solution had an absorbance of 1.037 at 510 nm and 0.422 at 656 nm in a 1.00-cm cell. Calculate the concentration of cobalt (in ppm) in the initial solution prepared by dissolving the sample.
Molar absorptivity data for the cobalt and nickel complexes with 2,3-quinoxalinedithiol are εCo = 36400 and εNi = 5520 at 510 nm and εCo = 1240 and ε Ni = 17500 at 656 nm. A 0.361-g sample was dissolved and diluted to 150.0 mL. A 25.0-mL aliquot was treated to eliminate interferences; after addition of 2,3-quinoxalinedithiol, the volume was adjusted to 50.0 mL. This solution had an absorbance of 1.037 at 510 nm and 0.422 at 656 nm in a 1.00-cm cell. Calculate the concentration of cobalt (in ppm) in the initial solution prepared by dissolving the sample. Calculate the concentration of nickel (in ppm) in the initial solution prepared by dissolving the sample.
Molar absorptivity data for the cobalt and nickel complexes with 2,3-quinoxalinedithiol are εCo = 36400 and εNi = 5520 at 510 nm and εCo = 1240 and ε Ni = 17500 at 656 nm. A 0.361-g sample was dissolved and diluted to 150.0 mL. A 25.0-mL aliquot was treated to eliminate interferences; after addition of 2,3-quinoxalinedithiol, the volume was adjusted to 50.0 mL. This solution had an absorbance of 1.037 at 510 nm and 0.422 at 656 nm in a 1.00-cm cell. Calculate the concentration of nickel (in ppm) in the initial solution prepared by dissolving the sample.
Molar absorptivity data for the cobalt and nickel complexes with 2,3-quinoxalinedithiol are εCo = 36400 and εNi = 5520 at 510 nm and εCo = 1240 and ε Ni = 17500 at 656 nm. A 0.361-g sample was dissolved and diluted to 150.0 mL. A 25.0-mL aliquot was treated to eliminate interferences; after addition of 2,3-quinoxalinedithiol, the volume was adjusted to 50.0 mL. This solution had an absorbance of 1.037 at 510 nm and 0.422 at 656 nm in a 1.00-cm cell. Calculate the concentration of cobalt (in ppm) in the initial solution prepared by dissolving the sample. Calculate the concentration of nickel (in ppm) in the initial solution prepared by dissolving the sample. I've asked this question multiple times and still have not gotten the right answer. This is my last question and I don't know what to do if this is also wrong.
Use the following information to answer the question. Molar absorptivity data for the cobalt and nickel complexes with 2,3-quinoxalinedithiol are ϵCo = 36400 and ϵNi = 5520 at 510 nm and ϵCo = 1240 and ϵ Ni = 17500 at 656 nm. A 0.457-g sample was dissolved and diluted to 200.0 mL. A 25.0-mL aliquot was treated to eliminate interferences; after addition of 2,3-quinoxalinedithiol, the volume was adjusted to 50.0 mL. This solution had an absorbance of 0.970 at 510 nm and 0.393 at 656 nm in a 1.00-cm cell. (a) Calculate the concentration of cobalt (in ppm) in the initial solution prepared by dissolving the sample. (b) Calculate the concentration of nickel (in ppm) in the initial solution prepared by dissolving the sample.
Co and Ni can be analysed simultaneously by their reaction with 2, 3-quinoxalinedithiol. Molar absorptivity data at the wavelengths are: Co-Complex Ni-Complex Molar Absorptivity.c 510 nm 36400 5520 656 nm 1240 17500 A 0.519 g sample was dissolved and diluted to 50 ml. A 25 ml aliquot was treated to eliminate interferences; after addition of 2, 3-quinoxalinedithiol, the volume was adjusted to 50 ml. this solution had an absorbance of 0.477 at 510 nm and 0.219 at 656 nm in 1.00 cm cell. Calculate the parts per million of Co and Ni in the sample.
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Vanadium forms a complex with peroxide which absorbs at 460 nm. A 3.96 × 10 -4M solution of vanadium peroxide (Solution A) exhibited an absorbance of 0.624 at 460 nm in a 1.000-cm quartz cuvette; a blank solution containing only solvent had an absorbance of 0.029 at the same wavelength. a) Find the molar absorptivity of vanadium peroxide complex. b) An unknown solution of vanadium peroxide complex in the same solvent and cuvette had an absorbance of 0.375 at 460 nm. Find the concentration of vanadium peroxide in the unknown solution. c) A concentrated solution vanadium peroxide in the same solvent was diluted from an initial volume of 5.00 mL to a final volume of 25.00 mL (Solution C) had an absorbance of 0.733 in the same cuvette. What is the concentration of vanadium peroxide in the concentrated solution (Solution B)? Answer the following questions: 1. Molar Absorptivity (M³1 cm1) of vanadium peroxide complex from Solution A at 460 nm 2. Concentration of vanadium peroxide in unknown…
The absorptivity data for the complexes formed when metal ions A and B react with 2,3-quinoxaline-dithiol at the wavelength of 512 and 656 nm are given in the table below: A 0.350 g of soil sample containing A and B metal ions was dissolved in dilute acid and subsequently diluted to 50 mL with distilled water. A 25 mL aliquot was treated to eliminate interferences, after the addition of 2,3-quinoxaline-dithiol, the volume was adjusted to 50 mL. This solution has an absorbance of 0.514 at 510 nm and 0.357 at 656 nm in a 1-cm cell. Calculate the respective percentage of the metal ions A and B.