(a) What would be the chemical shift of a peak that is observed at 655.2 Hz from the reference tetramethylsilane (TMS) recorded using a 90 MHz spectrometer ? (b) At what frequency would the chemical shift of chloroform (CHCl3, δ = 7.28 ppm) occur relative to TMS on a spectrum recorded on a 300 MHz spectrometer? (c) At what frequency and chemical shift would the signal for chloroform occur when using a 1 GHz NMR spectrometer?

(a) What would be the chemical shift of a peak that is observed at 655.2 Hz from the reference tetramethylsilane (TMS) recorded using a 90 MHz spectrometer ? (b) At what frequency would the chemical shift of chloroform (CHCl3, δ = 7.28 ppm) occur relative to TMS on a spectrum recorded on a 300 MHz spectrometer? (c) At what frequency and chemical shift would the signal for chloroform occur when using a 1 GHz NMR spectrometer?

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

Chapter19: Nuclear Magnetic Resonance Spectroscopy

Section: Chapter Questions

Problem 19.9QAP

See similar textbooks

Similar questions

If two signals differ by 1.5 ppm in a 300 MHz spectrometer, by how much do they differ in a 500 MHz spectrometer?
Using a 60 MHz spectrometer, a chemist observes the following peak: doublet, J = 7 Hz, at 2.50 ppm What would be the chemical shift of this same peak as measured by a 300 MHz spectrometer? (Include units.)
If two signals differ by 90 Hz in a 300 MHz spectrometer, by how much do they differ in a 500 MHzspectrometer?
A carbon signal measured in a 300MHz spectrometer with an observing frequency of 75.47MHz is found to have a chemical shift of 187.23 ppm. What is the resonance frequency of the carbon with this chemical shift?
In a 300 MHz NMR spectrometer, A) what is the Larmor frequency in MHz of a 15N nucleus? g H = N 26.752; g = 2.7126; B) Using the same NMR instrument, suppose that a 13C nucleus from a sample generates a signal which has a frequency of 11,250 Hz higher than that from the carbons in TMS. What is the chemical shift of that carbon atom from the sample? A) 30 MHz; B) 0.15 ppm OA) 25 MHz; B) 0.35 ppm A) 35 MHz; B) 0.30 ppm OA) 25 MHz; B) 0.55 ppm
Suppose you are analyzing mercury ions (Hg2+) in drinking water samples with atomic absorption spectroscopy. If the Hg2+ signal varies by a matrix of sample, which of the following should be used as a standard for calibration? Either cations or anions can be used if they are different from Hg2+, 0 H20 Any anions can be used if they are different from Hg2+ Any cations can be used if they are different from Hg?". Hg2+
The chemical shift value (δ) is measured by the ratio of shift in Hertz and the operational frequency of the spectrometer in MHz, give the equation to calculate the shift value
The 1H NMR spectrum of 1,2-dimethoxyethane (CH3OCH2CH2OCH3) recorded on a 300 MHz NMR spectrometer consists of signals at 1017 Hz and 1065 Hz downfield from TMS.(a) Calculate the chemical shift of each absorption. (b) At what frequency would each absorption occur if the spectrum were recorded on a 500 MHz NMR spectrometer?
The levels of Vitamin B1 in a sample of milk was determined using the Standard Addition method and technique of fluorescence spectroscopy. 18.0 ml of the milk sample was diluted to 20.0 ml using distilled water and then the fluorescence was measured. The resulting signal was 210 units. A spike was made by taking 18.0 ml of the same milk sample, adding 1.0 ml of a 6.0 ppm Vitamin B1 standard solution, and then diluting to 20.0 ml using distilled water. The signal of the spiked milk was 540 units. Calculate the concentration of Vitamin B1 in the original milk sample (in ppm). Report to 3 decimal places.
5. (a) In a 57 Fe Mössbauer 'experiment,it was found that the source had to be möved towards the sample at 2.2 mm s in order to attain resonant absorption of the y-ray. What is the shift (in MHz) between sample and source?
A proton jumps between two sites with δ = 2.7 and δ = 4.8. At what rate of interconversion will the two signals collapse to a single line in a spectrometer operating at 550 MHz?
The chemical shift of the CH3 protons in ethoxyethane (diethyl ether) is δ = 1.16 and that of the CH2 protons is 3.36. What is the difference in local magnetic field between the two regions of the molecule when the applied field is (i) 1.9 T, (ii) 16.5 T?