IR Spectroscopy

Question 1

O-H(ROH)

Answer 1

3600-3200 strong and broad

Question 2

N-H

Answer 2

3600-3200 medium and broad, one for each N-H

Question 3

O-H (RCO2H)

Answer 3

3600-2500 strong and very broad

Question 4

C-H (sp)

Answer 4

3300-3200 strong

Question 5

C-H (sp2)

Answer 5

3000-3200 Variable, depends on number of groups

Question 6

C-H (sp3)

Answer 6

2850-3000 variable, depends on number of groups

Question 7

O=C-H

Answer 7

2850-2750 two sharp peaks, may be masked

Question 8

C=-N

Answer 8

2260-2220 medium

Question 9

C=-C

Answer 9

2260-2100 medium narrow

Question 10

C=C

Answer 10

1700-1600 medium, narrow

Question 11

C=C (Ar)

Answer 11

1600-1500 two narrow peaks(aromatic overtones)

Question 12

C=O

Answer 12

1800-1600 very strong

Question 13

Polarity determines the intensity of absorbance how.

Answer 13

The more polar the bond, the more intense the absorbance
Ex. C-O bonds typically yield very intense absorbances.

Question 14

Number of bonds determine the intensity of the absorbance how?

Answer 14

The more bonds that absorb at the same wave number will yield a more intense absorbance.

Question 15

H-bonding determines broadness of absorbance how?

Answer 15

Bonds the have atoms involved in H-bonding will yield broad absorbances.
O-H bonds typically yield very broad absorbances.

Question 16

Bond Strength determines wave number absorbance how?

Answer 16

The strong the bond, the higher the wave number.

Question 17

Atomic mass determines the wave number how?

Answer 17

The lighter the atoms, the higher the wave number.

Question 18

Wave number

Answer 18

Number of waves per unit distance (# of waves per cm)

Question 19

Wavelength

Answer 19

Distance between wave crests

Question 20

Frequency

Answer 20

of waves per unit of time(# of waves per second)

Question 21

Spectroscopy

Answer 21

The study of the interaction of matter and electromagnetic radiation.

Question 22

C-O

Answer 22

1250-1050 strong

Question 23

C-N

Answer 23

1230-1020 medium