Chemical Analysis Activity Sheet 4 – 1HNMRQuestion 1How many signals would you expect to see in the...

Question

Chemical Analysis Activity Sheet 4 – 1HNMRQuestion 1How many signals would you expect to see in the 1H NMR spectrum of each of the following compounds?Question 2How would integration distinguish the 1H NMR spectra of the following compounds?Question 3The 1H NMR spectrum shown in the Figure below corresponds to one of the following compounds. Which compound is responsible for this spectrum?Question 4Indicate the number of signals and the multiplicity of each signal in the 1H NMR spectrum of each of the following compounds:Question 5Identify each compound from its molecular formula and its 1H NMR spectrum:Question 6Describe the 1H NMR spectrum you would expect for each of the following compounds, using relative chemical shifts rather than absolute chemical shifts:Question 7The 1H NMR spectra of three isomers with molecular formula C4H9Br are shown here. Which isomer produces which spectrum?Question 8   	Explain the principle behind NMR spectroscopy – how does it work?     	What is the difference between first and second order coupling in 1HNMR spectroscopy?   	How do you prepare samples for NMR?     	MRI is a very powerful medical imaging technique. How is this related to NMR? How does MRI work?   
	
Document Preview: Chemical Analysis Activity Sheet 4 – 1HNMRQuestion 1How many signals would you expect to see in the 1H NMR spectrum of each of the following compounds?Question 2How would integration distinguish the 1H NMR spectra of the following compounds?Question 3The 1H NMR spectrum shown in the Figure below corresponds to one of the following compounds. Which compound is responsible for this spectrum?Question 4Indicate the number of signals and the multiplicity of each signal in the 1H NMR spectrum of each of the following compounds:Question 5Identify each compound from its molecular formula and its 1H NMR spectrum:Question 6Describe the 1H NMR spectrum you would expect for each of the following compounds, using relative chemical shifts rather than absolute chemical shifts:Question 7The 1H NMR spectra of three isomers with molecular formula C4H9Br are shown here. Which isomer produces which spectrum?Question 8Explain the principle behind NMR spectroscopy – how does it work?What is the difference between first and second order coupling in 1HNMR spectroscopy?How do you prepare samples for NMR?MRI is a very powerful medical imaging technique. How is this related to NMR? How does MRI work?

Robert · Accepted Answer

IR and Combined
Question 1
a. Two 
b. 1 
c. 2 
d. 3 
e. 3 
f. 4 
g. 3 
h. 3 
i. 3 
j. 3 
k. 2 
l. 3 
m. 3 
n. 1 
o. 3 
Question 2  
This is found out by taking the ratio of equivalent protons.
a. 9:2 
b. 6:2 
c. 3:6 
Question 3  
Answer: B
Question 4
a. Three signals - 2H triplet (more up field),  2H triplet( downfield) and 2H triplet. 
(medium) 
b. Two signals- Both are 2H- triplets 
c. Three signals- 1H- triplet, 2H triplet, 2H triplet 
Question 5
a. C9H12 
The compound is probably propyl benzene.
 Doble bond equivalent= 4. It  means that the compound is aromatic 
 The triplet peak at 7.2 ppm is from aromatic protons. There are three 
distinguishable aromatic protons, hence, three peaks in the same range 
obtained. 
 The triplet at 2.6 ppm is from the 2H, CH2 protons directly attached to 
the aromatic ring. 
 The multiplet at 1.6 ppm indicates the Second CH2 group attached to the 
above CH2. Multiplet due to the coupling from adjacent 4 non-
equivalent protons. 
 The triplet at 1 ppm due to the CH3 group of the side chain.
b. C5H10O 
The probable compound is  3-pentanone 
The compound is symmetric and has only two different types of magnetically 
non-equivalent protons. 
 The quartet at 2.4 ppm is due to the 2H of CH2 groups 
 The triplet at 1.1 ppm due to the 3H of CH3 at the terminal end
c. C9H10O2
The probable structure of the compound is 
 
The double bond equivalent is  5. It means that the compound is aromatic 
and there is an extra double bond another than the aromatic ring. This extra 
double bond is assigned to the Carbonyl group of the COOH. 
 The singlet of 1H at 8 indicates the H of COOH group 
 The multiplets around 7 ppm is of the aromatic protons. 
 The quartet at 4.4ppm is due to the CH2 group attached to COOH 
 The Triplet at 1.4ppm is due to the CH2 attached to the aromatic ring
Question 6
a. This compound is symmetric. There are two magnetically non-equivalent 
protons. There will be two peaks of the ratio 1:1. 
 Triplet due to 2H of  CH2 near Br at around  1 ppm 
 Triplet due to 2H of CH2 at the C number 2  at round 2 ppm 
b. The compound not symmetric. 4 magnetically non equivalent protons. Hence 4 
peaks can be expected. 
 Singlet around 3.5ppm due to the 3H of CH3 group 
 Triplet around 3.3 ppm of high intensity due to the 3H of CH2  attached 
to the O 
 Triplet at 3.2 ppm due to the 2H of CH2 attached to Br 
 Multiplet at 2 ppm is due to the 2H of middle CH2 
c. The compound is having only one proton magnetically distinguishable. So a 
singlet at around 1 ppm will be the only peak 
d. There are 3 magnetically different protons. 
 Triplet of 3H at 0.9ppm indicates CH3 
 Singlet of high intensity at 1.

Chemical Analysis Activity Sheet 4 – 1 HNMR Question 1 How many signals would you expect to see in the 1 H NMR spectrum of each of the following compounds? Question 2 How would integration distinguish...

Solution

Answer To This Question Is Available To Download

Related Questions & Answers

Submit New Assignment