
(a)
Interpretation:
The appearance of the high resolution 13C spectrum of methyl formate when the protons are not decoupled should be predicted.
Concept introduction:
13C isotope of carbon has low
(b)
Interpretation:
The appearance of the high resolution 13C spectrum of acetaldehyde when the protons are not decoupled should be predicted.
Concept introduction:
13C isotope of carbon has low natural abundance. 12C is the most abundant isotope in nature. But it is NMR inactive because the spin quantum number is zero. Since 13C is less likely to find in nature there is a very low probability of finding two 13C nuclei which are close to each other. So there is no observable spin-spin coupling between adjacent carbons in 13C NMR spectra. But there are 13C and 1H coupling which leads to large number of splitting patterns in the spectrum. To obtain simplified 13C spectrum scientists use a method called broadband decoupling. This technique avoids the C-H coupling signal, so that all carbon signals appear as singlets.
(c)
Interpretation:
The appearance of the high resolution 13C spectrum of acetone when the protons are not decoupled should be predicted.
Concept introduction:
13C isotope of carbon has low natural abundance. 12C is the most abundant isotope in nature. But it is NMR inactive because the spin quantum number is zero. Since 13C is less likely to find in nature there is a very low probability of finding two 13C nuclei which are close to each other. So there is no observable spin-spin coupling between adjacent carbons in 13C NMR spectra. But there are 13C and 1H coupling which leads to large number of splitting patterns in the spectrum. To obtain simplified 13C spectrum scientists use a method called broadband decoupling. This technique avoids the C-H coupling signal, so that all carbon signals appear as singlets.

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Chapter 19 Solutions
Principles of Instrumental Analysis
- 2Helparrow_forwardplease add appropriate arrows, and tell me clearly where to add arrows, or draw itarrow_forwardWhat I Have Learned Directions: Given the following reaction and the stress applied in each reaction, answer the question below. A. H2(g) + Cl2(g) 2 HCl(g) Stress applied: Decreasing the pressure 1. What is the Keq expression? 2. What will be the effect in the number of moles of HCl(g)? 3. What will be the Equilibrium Shift or the reaction? B. Fe3O4(s) + 4 H2(g) + heat 53 Fe(s) + 4 H₂O(g) Stress applied: Increasing the temperature 1. What is the Keq expression?. 2. What will be the effect in the volume of water vapor collected? 3. What will be the Equilibrium Shift or the reaction? C. 4 NH3(g) + 5 O2(g) 4 NO(g) + 6 H2O(g) + heat Stress applied: Increasing the volume of the container 1. What is the Keq expression?. 2. What will be the effect in the amount of H₂O? 3. What will be the Equilibrium Shift or the reaction?arrow_forward
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- b) Circle the substrate that would not efficiently generate a Grignard reagent upon reaction with Mg in ether. CI Br ד c) Circle the Grignard reagents that contain incompatible functional groups. MgBr HO MgBr MgBr MgBr MgBr HO MgBrarrow_forwardQ2: Predict all organic product(s), including stereoisomers when applicable. PCC OH a) CH2Cl2 Page 2 of 5 Chem 0310 Organic Chemistry 1 HW Problem Sets b) .OH Na2Cr2O7, H+ OH PCC CH2Cl2 c) OHarrow_forwardd) Circle the substrates that will give an achiral product after a Grignard reaction with CH3MgBr. Harrow_forward
- Principles of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning
