P11E.2 Suppose that three conformations are proposed for the nonlinear molecule H,O, (1, 2, and 3). The infrared absorption spectrum of gaseous H,O, has bands at 870, 1370, 2869, and 3417 cm. The Raman spectrum of the same sample has bands at 877, 1408, 1435, and 3407 cm. All bands correspond to fundamental vibrational wavenumbers and you may assume that: (a) the 870 and 877 cm bands arise from the same normal mode, and (b) the 3417 and 3407 cm bands arise from the same normal mode. (i) If H,O, were linear, how many normal modes of vibration would it have? (ii) Give the symmetry point group of each of the three proposed conformations of nonlinear H,O,. (iii) Determine which of the proposed conformations is inconsistent with the spectroscopic data. Explain your reasoning. 2

P11E.2 Suppose that three conformations are proposed for the nonlinear molecule H,O, (1, 2, and 3). The infrared absorption spectrum of gaseous H,O, has bands at 870, 1370, 2869, and 3417 cm. The Raman spectrum of the same sample has bands at 877, 1408, 1435, and 3407 cm. All bands correspond to fundamental vibrational wavenumbers and you may assume that: (a) the 870 and 877 cm bands arise from the same normal mode, and (b) the 3417 and 3407 cm bands arise from the same normal mode. (i) If H,O, were linear, how many normal modes of vibration would it have? (ii) Give the symmetry point group of each of the three proposed conformations of nonlinear H,O,. (iii) Determine which of the proposed conformations is inconsistent with the spectroscopic data. Explain your reasoning. 2

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...

See similar textbooks

Similar questions

(b) The lowest three vibrational energy levels of 127|35CI lie at 191.77, 573.06, and 951.34 cm-1. Determine the force constant, zero-point energy, well- depth and bond dissociation energy for 127135CI.
(i) Explain how the mass of the particle(s) involved affects the separation between energy levels in quantum mechanics. (ii) Explain why the sensitivity of an NMR experiment is affected by the strength of the applied magnetic field. (iii) Explain why, to a good approximation, rotational and vibrational transitions do not change the energies of electrons.
In the infrared spectrum of He79Br, there is an intense line at 2559 cm−1 . Calculate the force constant of He^79 Br and the period of vibration of He^79 Br.
(4) For a rotational-vibrational spectrum of H8'Br (B = 8.46 cm-1) taken at 520 K, determine the R-branch transition that is expected to be the most intense.
4. To what do the terms P, Q, and R branch refer to in a rotational-vibrational spectrum?
The force constant for the bond in CO is 1857 N/m, Calculate the vibrational frequencies (in Hz) of 12C160, 13C160, 12C180, and 13C180. Use integer relative masses for this estimate.
7 The fundamental vibrational wavenumber ( ṽ) for 1H 127I molecule is 23096 cm-1 A. Determine the force constant (k) of 1H 127I B. Calculate the value of for 2H 127I. Show all calculations and the units. Explain the reasoning
5. Calculate the frequency and wavenumber of the J = 3 € 2 transition in the pure rotational spectrum of 14N160. The equilibrium bond length is 115 pm. Does the frequency increase or decrease if centrifugal distortion is considered?
Please don't provide handwritten solution ...
Explain how by plotting the J values against the Energies allows us to determine the constants?
Use group theory to predict the number of v(CO) stretching vibrations you would expect to observe in the IR and Raman spectra of cis and trans isomers of Mo(CO)4(PPh3)2. Can these isomers be differentiated by vibrational spectroscopy? (ii) Can these isomers be differentiated by 31P{H} and 13C {¹H} spectroscopy? Fully explain your answer in both cases explaining what you would expect to see in each spectrum. (iii) Reaction of both isomers with more PPh3 affords mixtures of fac and mer isomers of [Mo(CO)3 (PPh3)3]. Give the point groups for each. Can they be distinguished by IR spectroscopy? Please give me all answers
The following are infrared absorption wavenumbers (in cm) of two diatomics. Calculate the force constants of the bonds and identify which bond is stiffer. а. H3$Cl: 2990 (in cm) and H$ Br: 2650 (in cm)