The IR (infrared) spectra of two pure compounds (0.010 M compound A in solvent and 0.010 M compound B in solvent) aregiven. The pathlength of the cell is 1.00 cm. The y-axis in the spectra is transmittance rather than absorption, so that thewavenumbers at which there is a dip in the curve correspond to absorption peaks.A mixture of A and B in unknown concentrations gave a percent transmittance of 49.8% at 2976 cm¹ and 44.9% at 3030 cm-1Wavenumber0.010 M A0.010 M BUnknown3030 cm-135.0%93.0%44.9%2976 cm-¹76.0%42.0%49.8%What are the concentrations of A and B in the unknown sample?Transmittance (%)1009080706050402976 cm-1303030 cm-120Pure A10Pure B030402990Wavenumber (cm-1)29402890

To solve the concentrations of A and B in the unknown sample, create two equations from the data in…

Answered: The IR (infrared) spectra of two pure…

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter26: Molecular Absorption Spectrometry

Section: Chapter Questions

Problem 26.32QAP

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Potassium dichromate (K2Cr2O7) and potassium permanganate (KMnO4) give overlapping UV-Vis absorption spectra in 1 M sulphuric acid. K2Cr2O7 shows an absorption maximum at 440 nm and KMnO4 shows the absorption maximum at 545 nm . An unknown sample solution containing a mixture of K2Cr2O7 and KMnO4 was analyzed using a 1-cm cell and the absorbance values at these two wavelengths were as follows: A440 = 0.515 and A545 = 0.835 The absorbance values for standard solutions of K2Cr2O7 (1.00 x 10-3 M) and KMnO4 (2.00 x 10-4 M) in 1 M sulphuric acid using the same 1 cm cell were as follows: Calculate the concentrations of K2Cr2O7 and KMnO4 in the unknown sample.
Potassium dichromate and potassium permanganate have overlapping absorptionspectra in 1M H2SO4 . K2Cr2O7 has an absorption maxima at 440 nm, and KMnO 4 has a band at 545nm (the maximum is actually at 525 nm, but the longer wavelength is generally used whereinterference from K2C2O7 is less). A mixture is analyzed by measuring the absorbance at these twowavelengths with the following results: A 440 =0.405, A 545 =0.712 in a 1-cm cell. The absorbances ofpure solutions of K2Cr2O7 (1x10 -3 M) and KMnO 4 (2.00x10 -4 M) in 1 M H 2 SO 4 , using the same cell gavethe following results: A Cr,440 = 0.374, A Cr,545 = 0.009, A Mn,440 =0.019, A Mn,545 = 0.475. Calculate theconcentrations of dichromate and permanganate in the sample solution.
At 520 nm with a 1.00 cm cell a 8.24 ppm solution of KMnO4 has a transmittance of 0.126. What is the molar absorptivity of KMnO4 at 520 nm?
The molecule with strong absorptions at 1800 and 1760 cm ^ -1 is:
When measured in a 1.00 cm cuvette, a 4.1x10M solution of species X exhibited absorbances of 0.1025 and 0.533 at 530 nm and 325 nm, respectively. A8.20x10 M solution of species Y gave absorbances of 0.230 and 0.508 at 530 nm and 325 nm, respectively. Both species were dissolved in the same solvent, and the solvent's absorbance was 0.000 and 0.000 at 530 nm and 325 nm, respectively, in a 1 cm cuvette. Calculate the concentrations of X and Y in an unknown solution that yielded absorbance data of 0.683 at 530 nm and 1.351 at 325 nm in a 1.0 em cuvete O A.X-4.20 x10 M Y=3.20 x104 M OBX-1.25 X10M Y420 x10-SM OCX-3.75x1oM Y-1 A10M OD.X-3.80 x 10M Y=2.10x10M
3) A compound, X, with a molecular weight of 292.16 g/mol was dissolved in a 5.00 mL volumetric flask and diluted to the mark. A 1.00 mL aliquot of this was withdrawn, placed into a 10.00 mL volumetric flask and diluted to the mark. The absorbance at 340 nm was 0.427 in a 1.000 cm cuvette. The molar absorptivity of X at 340 nm is 6130 M-¹ cm-¹ a) Using Beer's Law, what is the [X] (concentration in molarity) for the diluted solution in the cuvet ? mmmmm b) Use the dilution equation (McVc = MdVa) to calculate [X] in the original 5.00 mL flask. c) How many milligrams of X was used in the original solution ? (Find total moles X using original concentration and original volume - and then use the molar mass to go from moles to grams and then milligrams)
Consider the IR spectrum of the product, isopentyl ethanoate(attached below). Please comment on the product absorbances and differences from the IR spectrum of the starting material, 3-methylbutanol.Then Please comment on the product absorbances and differences from the IR spectrum of the starting material, 3-methylbutanol.
A student prepared several solutions of Molecule Bright, each at a different concentration. The absorbance of each solution was measured at 405 nm with a path length of 0.730 cm. The student then plotted the absorbance of each sample vs. its concentration (in mM), and found a best-fit line of y = 3.726x + 0.828. Calculate the molar absorptivity of the Molecule Bright (in M-1 cm-1).
12D.15 At low resolution, the strongest absorption band in the infrared absorption spectrum of 12C¹6O is centred at 2150 cm-¹. Upon closer examination at higher resolution, this band is observed to be split into two sets of closely spaced peaks, one on each side of the centre of the spectrum at 2143.26 cm-¹1. The separation between the peaks immediately to the right and left of the centre is 7.655 cm-¹. Make the harmonic oscillator and rigid rotor approximations and calculate from these data: (a) the vibrational wavenumber of a CO molecule, (b) its molar zero-point vibrational energy, (c) the force constant of the CO bond, (d) the rotational constant B, and (e) the bond length of CO.
Interpret the principal absorption bands in the infrared spectrum of methyl salicylate
What is involved in Phases l and Phases ll of biotransformation?
please label any peaks/structures

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