Question

2. (4 points) Which of the following statements is true regarding symmetrical compounds in NMR experiments? a. a symmetrical compound will always have the same number of unique carbons and hydrogens b. a symmetrical compound will never have diastereotopic hydrogens c. a symmetrical compound can be cyclic, linear, or branched d. a symmetrical compound is always achiral 3. (4 points) How many ?H-NMR signals would be in the spectrum for the following compound? Diastereotopic hydrogens would produce different signals. (R)-2-iodo-pentane a. 5 b. 6 c. 7 d. 4 4. (4 points) What is the splitting pattern for Ha in the following structure? Ha a. singlet b. doublet c. pentet d.sextet 5. (4 points) Which of the following statements is true regarding C-NMR a. Carbon-13 is more sensitive than hydrogen NMR b. Carbon-13 resonances appear over a broader range than H-NMR c. Carbon-13 does not couple do adjacent carbons d. Carbon-13 nuclei cannot couple with Hydrogen nuclei

2) Which of the following statements is true regarding symmetrical compounds in NMR experiments?

3) How many H-NMR signals would be in the spectrum for the following compounds? Diasteretopic hyrodgens would produce different signals.

4) What is the splitting pattern for Ha in the following structure?

5) Which of the following statements is true regarding C-NMR?

Answer 1

Solution:

2. Which of the following statements is true regarding symmetrical compounds in NMR experiments,

Answer is a and c

3. How many H-NMR signals would be in the spectrum for the following compounds? Diasteretopic hyrodgens would produce different signals,

Answer is d. 4

4. What is the splitting pattern for Ha in the following structure,

Answer is a. Singlet

5. Which of the following statements is true regarding C-NMR,

Answer is b: carbon-13 resonance appear over a broader range than H-NMR