A" forms a pink-yellow complex ion in solution at Amax = 396 nm, while a red-green complex of B" in solution at Amax = 550 nm. The resulting r absorbance spectra of the ions significantly overlap. The table below shows the molar absorptivities (M cm-) for the metal complexes at the two wavelengths. Analyte 550 € 396 9970 84 B2. 34 856 To determine the concentration of these analyte ions in a mixture, the mixture absorbance is analyzed in a cell with a pathlength of 1.00 cm at 550 nm and at 396 nm, yielding values of 0.183 and 0.109 respectively. What is the molar concentrations of A* in the sample? (round off to 3 SF scientific notation, (round off to 3 SF scientific notation, What are the molar concentrations of B" in the sample? Show your complete solution below (or may attach photo of the written solution)

A" forms a pink-yellow complex ion in solution at Amax = 396 nm, while a red-green complex of B" in solution at Amax = 550 nm. The resulting r absorbance spectra of the ions significantly overlap. The table below shows the molar absorptivities (M cm-) for the metal complexes at the two wavelengths. Analyte 550 € 396 9970 84 B2. 34 856 To determine the concentration of these analyte ions in a mixture, the mixture absorbance is analyzed in a cell with a pathlength of 1.00 cm at 550 nm and at 396 nm, yielding values of 0.183 and 0.109 respectively. What is the molar concentrations of A* in the sample? (round off to 3 SF scientific notation, (round off to 3 SF scientific notation, What are the molar concentrations of B" in the sample? Show your complete solution below (or may attach photo of the written solution)

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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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).
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.
The molar absorptivity (ε) of the FeSCN2+ complex ion is 4700 M-1 · cm-1 at a wavelength of 450 nm. Using a 1-cm sample tube, you measure the absorbance as (2.0x10-1). What is the concentration of FeSCN2+?
Palladium (II) and gold (III) can be analyzed simultaneously through reaction with methiomeprazine (C19H24N2S2). The absorption maximum for the Pd complex occurs at 480 nm, while that for the Au complex is at 635 nm. Molar absorptivity data at these wavelengths are Molar Absorptivity, ε 480 nm 635 nm Pd complex 3.55 × 103 5.64 × 102 Au complex 2.96 × 103 1.45 × 104 A 25.0-mL sample was treated with an excess of methiomeprazine and subsequently diluted to 50.0 mL. Calculate the molar concentrations of Pd(II), CPd, and Au(III), CAu, in the sample if the diluted solution had an absorbance of 0.533 at 480 nm and 0.590 at 635 nm when measured in a 1.00-cm cell. explain each step
Consider the octahedral complex [FeBr6] 4−. In water solution it has an absorption peak at 864 nm with a molar absorptivity (ε) of 3.6 L mol-1 cm-1 . (I have a, b, and c, I need help with d, e, and f.) (a) What is the energy (in wavenumbers, cm-1 ) of the absorption peak? Show all work. (b) How many valence d electrons does the metal center have? Justify your answer. (c) How many unpaired electrons per molecule would a magnetic susceptibility experiment predict? What would the S number be for this transition metal center? Justify your answers. (d) What electronic transition results from absorption of 864-nm light? (e) Calculate the ligand stabilization energy (in units of ∆o) and units of coulombic (Πc) energy. (f) How would the ligand field strengths (∆o) of [Fe(NH3)6] 2+ and [Fe(bipy)3] 2+ differ from that of [FeBr6] 4−? Why?
Vanadium has two isotopes (50V, 0.25%; 51V,99.75%). The EPR spectrum of an aqueous solutionof [VO(OH2)5]2+ shows an 8-line pattern, andg-values of gzz=1.932, gxx = 1.979 and gyy=1.979were determined. What can you deduce from the data?
By using the given 1) electronic absorption spectrum, 2) the Tanabo-Sugano diagram for d3 complex in octahedral ligand field and 3) the absorption/emission spectra, explain the following: a) Ligand field states (to support your explanation show the filling of the orbitals) b) Radiative transitions (to support your explanation refer to fluorescence, phosphorescence and Stokes’ shift)
The ESI mass spectrum (positive mode) of the complexshown below contained a peak envelope with m/z527.9 (100%), 528.9 (15%), 529.9 (46%), 530.9(7%), 531.9 (0.5%). A group of peaks of lowintensity and with spacings of m/z ¼ 1 was alsoobserved around m/z 994. (a) What is the oxidationstate of Cu in the complex? (b) Assign the majorpeak and account for the isotope pattern. (c) Suggesthow the minor peak arises. [The mass spectrum of the complex complex is shown on pic.]
The complex ion [Fe(CN)6]3− has an electronic absorption spectrum with a maximum at 305 nm. Estimate a value of Δo for the complex.
Consider the octahedral complex [FeBr6] 4−. In water solution it has an absorption peak at 864 nm with a molar absorptivity (ε) of 3.6 L mol-1 cm-1 . (a) What is the energy (in wavenumbers, cm-1 ) of the absorption peak? Show all work. (b) How many valence d electrons does the metal center have? Justify your answer. (c) How many unpaired electrons per molecule would a magnetic susceptibility experiment predict? What would the S number be for this transition metal center? Justify your answers. (d) What electronic transition results from absorption of 864-nm light? (e) Calculate the ligand stabilization energy (in units of ∆o) and units of coulombic (Πc) energy. (f) How would the ligand field strengths (∆o) of [Fe(NH3)6] 2+ and [Fe(bipy)3] 2+ differ from that of [FeBr6] 4−? Why?
Calculate ∆ in kJ/mol if a d1 complex has an absorption maximum at 545 nm.
The molar absorptivity (ε) of the FeSCN2+ complex ion is 4700 M-1 · cm-1 at a wavelength of 450 nm. Using a 1-cm sample tube, you measure the absorbance as (2.0x10-1). What is the concentration of FeSCN2+? What is your answer? _____________x10^_____