The rule you generated in Question 14b for finding the [M]* peak on the mass spectrum of an unknown molecule does not work very well if there is a Br or Cl in the molecule. Shown below are spectra of various compounds containing one Br or Cl. a. Find the [M] and [M+2]* peak on each spectrum.
Analyzing Infrared Spectra
The electromagnetic radiation or frequency is classified into radio-waves, micro-waves, infrared, visible, ultraviolet, X-rays and gamma rays. The infrared spectra emission refers to the portion between the visible and the microwave areas of electromagnetic spectrum. This spectral area is usually divided into three parts, near infrared (14,290 – 4000 cm-1), mid infrared (4000 – 400 cm-1), and far infrared (700 – 200 cm-1), respectively. The number set is the number of the wave (cm-1).
IR Spectrum Of Cyclohexanone
It is the analysis of the structure of cyclohexaone using IR data interpretation.
IR Spectrum Of Anisole
Interpretation of anisole using IR spectrum obtained from IR analysis.
IR Spectroscopy
Infrared (IR) or vibrational spectroscopy is a method used for analyzing the particle's vibratory transformations. This is one of the very popular spectroscopic approaches employed by inorganic as well as organic laboratories because it is helpful in evaluating and distinguishing the frameworks of the molecules. The infra-red spectroscopy process or procedure is carried out using a tool called an infrared spectrometer to obtain an infrared spectral (or spectrophotometer).
![27. The rule you generated in Question 14b for finding the [M] peak on the mass spectrum of an
unknown molecule does not work very well if there is a Br or Cl in the molecule. Shown below
are spectra of various compounds containing one Br or Cl.
a.
Find the [M] and [M+2]* peak on each spectrum.
Relative Intensity
100-
Relative Intensity
80-
60
20-
0-mmm
100-
80
60-
40
18--8163
20-
25
HS-NU-2127
0-forttitor
10
20
b.
30
50
40
50
Br
pretztenyeregtelefongum
75
m/z
60
m/z
Bri
70
100
(2) one Br atom.
125
effleyttim
90
80
|||||||
100 110
Relative Intensity
100
Relative Intensity
80
60-
40
20
0-m
100-
80
60
40
20
15-MM-0968
0-
spatepragning
25
115--1439
25
50
50
75
NH₂
100
m/z
mn|||
75
m/z
125
100
150
125
Write a rule for quickly identifying from a mass spectrum if an unknown molecule has...
(1) one Cl atom.
Note: The mass spectrum of a molecule with more than one Cl or Br can be quite complex, so we will limit cases to one Cl or Br.
Write a new rule for finding the [M]* peak that takes into consideration the fact that Br and
Cl have very large [M+2]* peaks.
C.
28. Each of the spectra above contains an [M+3]* peak. This peak arises because 37C1 and ³¹Br are so
common that there are a significant number of ions with a heavy isotope of both carbon and the
halogen, e.g, [one ¹³C and one ³7C1] or [one ¹3C and 8¹Br]. Mark this [M+3]* peak on each
spectrum above.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Fa1871893-1489-414f-ba40-94b584c7772f%2Fc2695086-153c-4734-ba21-f75969c480ac%2Favy61ym_processed.png&w=3840&q=75)
![29.
On the mass spectrum of hexane in this activity, the [M]* peak (at m/z = 86) has an intensity of 10.
Calculate the expected intensity of the [M+1] peak in this spectrum.
30. Calculate the molecular weight of each of the following molecules using the most common
isotope of each element:
H3C
NH₂
H
CH3
NH3
N=C-H
CH3
r
H
H
31. What do the molecular weights in the previous question have in common with one another that set
them apart from ALL the molecular weights in the [M]* column in Model 6?
Memorization Task L2.5: Nitrogen Rule
It turns out that any molecule with an odd number of nitrogen atoms (1, 3, 5, etc.) will have an odd
molecular weight and vice versa. This "nitrogen rule" is a consequence of the fact that ¹4N is the only
common organic element that makes an odd number of bonds but has an even molecular weight.
32. Give examples of two very common elements that make an even number of bonds and whose
most common isotope has an even molecular weight.
33. Give an example of at least one element that makes an odd number of bonds and whose most
common isotope has an odd molecular weight.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Fa1871893-1489-414f-ba40-94b584c7772f%2Fc2695086-153c-4734-ba21-f75969c480ac%2Frg2oty_processed.png&w=3840&q=75)
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