CHEM 2081 Exam 1

Question 1

M-H Stretch Range
(M: N, O, C)

Answer 1

2800-3600 (cm-1)

Question 2

M=C Stretch Range
(M: O, C)

Answer 2

1450-1780 (cm-1)

Question 3

IR Nitrile/Alkyne Stretch Range

Answer 3

2100-2260 (cm-1)

Question 4

IR Fingerprint Region

Answer 4

1500 cm-1 and lower, contains C=C, C-C, and C-O stretches, as well as bond bends

Question 5

Mass Spec. Parent Peak

Answer 5

Furthest substantial peak to the right in a mass spectroscopy spectrum

Question 6

Mass Spec. Base Peak

Answer 6

Tallest peak in a mass spectroscopy spectrum

Question 7

Mass Spectrometry M+1 vs. M+2 Peaks

Answer 7

Isotopic peaks appear depending on natural abundance of heavy isotopes (e.g., Cl will have its M+ peak (35) and an M+2 peak (37) in a 3:1 ratio (75% : 25%))

Question 8

13C NMR

Answer 8

Each peak correlates to just one unique carbon (can represent multiple), no splitting

Question 9

1H NMR Integration

Answer 9

Value of area under the curve is proportional to the number of atoms represented

Question 10

Long Range NMR Coupling

Answer 10

Occurs when protons are separated by 3 bonds or more, exhibit weak coupling through a pi bond system

Question 11

Amine/Amide IR Stretches

Answer 11

Directly related to quantity of H atoms (e.g., 2 H atoms attached will lead to 2 IR peaks)