Deuterated solvents such as CDCl3 are used to dissolve NMR samples. When using C

Question

Deuterated solvents such as CDCl3 are used to dissolve NMR samples. When using CDCls a peak will appear at 7.3 ppm which can be used to calibrate your spectrum. Since the NMR cannot detect a deuterium atom why does the peak at 7.3 ppm appear? Question 5. Answers A. NMR can detect and report deuterium atoms, that is why deuterated solvent are used, and in the case of CDCl3 the deuterium has a resonance of 7.3 ppm. Deuterated CDC, is not detected by the NMI, but the less than 1% CHC, which is contained in a typical bottle of CDCl3 causes the peak at 7.3 ppm. B. C. The deuterium on the CDCb, will ionize and exchange with an acid hydrogen atom on the molecule dissolved in the NMR solvent, this leads to the formation of CHCl3 and the peak at 7.3 ppm. Question 6. (10 points) The compound peak that a in the NMR spectra at 0.0 ppm is what d and explain the presence of this Question 6. Answers A. At 0.0 ppm a peak is observed that is the result of the presence of the deuterium in the deuterated solvent, the presence of deuterium at 0.0 ppm is used to calibrate the NMR spectrum At 0.0 ppm a peak is observed that is the result of the presence of H:0 (water), unfortunately NMR solvents like almost every solvent, unless highly purified, will contain traces of water B. C. At 0.0 ppm a peak is observed that is the result of the presence of trimethylsilane (TMS), NMR solvents can be purchased with or without TMS. The role of TMS is to calibrate the NMR spectrum D. At 0.0 ppm a peak is observed that is the result of the presence of D:O (Heavy Water, in which the hydrogens have been replaced with deuterium atoms), NMR solvents can be purchased with or without D.O. The role of Di0O is to calibrate the NMR spectrum. Question 7. (10 points) Analyze the following compound and answer the following question. If you ignore the peaks associated with the aromatic ring, how many peaks would you expect to see in the proton NMR of the compound above (also, ignoring all peaks associated with deuterated solvent) Question 7. Answers A. 1 B. 2

Explanation / Answer

Answer of question 5 : (B)

Answer for Question 6 : (C) .

Answer for 7 : (A). if we ignore peak due to aromatic ring then we get onle one peak due to CH3. 1 because all the 3 Hydrogens are in same environment.   

Related Questions

Navigate

• Browse (All)
• Browse D
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.