The natural abundance of 13C is only 1.1%. Furthermore, its sensitivity in NMR spectroscopy (a measure of the energy difference between a spin aligned with or against an applied magnetic field) is only 1.6% that of 1H. What are the relative signal intensities expected for the 1H-NMR and 13C-NMR spectra of the same sample of Si(CH3)4?

Identify as many peaks as possible. This is the IR Spectroscopy of an unknown liquid sample.

Identify the peaks for this IR

Combine the chemical shifts, integrals, and spin-spin splitting patterns in NMRspectra with information from infrared and mass spectra to determine the structuresof organic compounds

2 PPM Calculate the coupling constant (J) for the multiplets reported in the 'H-NMR expansion above, knowing that the corresponding spectrum was recorded at 400 MHz. Report your result with four significant figures. 2.444 2.410 2.376 2.342 2.005 1 1.244 1.210 1.176 3.012

The chemical shift of the CH3 protons in acetaldehyde (ethanal) is δ = 2.20 and that of the CHO proton is 9.80. What is the difference in local magnetic field between the two regions of the molecule when the applied field is (a) 1.2 T, (b) 5.0 T?

An organic molecule shows two absorption peaks at 870 and 975 Hz in a magnetic field of 3T. The corresponding chemical shifts in ppm, respectively, are (Given: Magnetogyric ratio for 13C = 6.7263 x 107 rad T-1s1 and I = 1/2) 30.4 and 27.1 27.1 and 30.4 8.7 and 9.75 9 and 10

31P (¹H) NMR Predict the 31P(¹H) NMR spectrum for Ph,PBH, and explain your answer. (For ¹¹B, spin number 1 = 3/2)

From the spectra, determine the structure of the molecule.Remember to ignore the triad in the 13 C NMR spectrum at 77 ppm thatcomes from the NMR solvent

The volatile organic compounds (VOCs) produced by decomposing tissue and organs were studied in an effort to identify possib human-specific markers (PLoS ONE 2015 10(9): e0137341.). Of 452 VOCs isolated, six were found to be unique to humans, so th prove to be a useful tool for forensic chemists trying to determine the source of unidentified remains. There are two doublets in expected ¹H NMR spectrum of the following human-specific VOC. Identify the protons giving rise to each doublet. 1 2 H3C H3C- оооооооо 238 H 8 HH HH 3 HH CH3 5 7 Identify the two groups of protons that give rise to the doublets in the spectrum. CH3 8